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ISL3332, ISL3333
Data Sheet May 27, 2008 FN6362.0
3.3V, 15kV ESD Protected, Two Port, Dual Protocol (RS-232/RS-485) Transceivers
The ISL3332, ISL3333 are two port interface ICs where each port can be independently configured as a single RS-485/422 transceiver, or as a dual (2 Tx, 2 Rx) RS-232 transceiver. With both ports set to the same mode, two RS-485/RS-422 transceivers, or four RS-232 transceivers are available. If either port is in RS-232 mode, the onboard charge pump generates RS-232 compliant 5V Tx output levels from a single VCC supply as low as 3.15V. The transceivers are RS-232 compliant, with the Rx inputs handling up to 25V. In RS-485 mode, the transceivers support both the RS-485 and RS-422 differential communication standards. The receivers feature "full failsafe" operation, so the Rx outputs remain in a high state if the inputs are open or shorted together. The transmitters support up to three data rates, two of which are slew rate limited for problem free communications. The charge pump disables when both ports are in RS-485 mode, thereby saving power, minimizing noise, and eliminating the charge pump capacitors. Both RS-232 and RS-485 modes feature loopback and shutdown functions. Loopback internally connects the Tx outputs to the corresponding Rx input, to facilitate board level self test implementation. The outputs remain connected to the loads during loopback, so connection problems (e.g., shorted connectors or cables) can be detected. Shutdown mode disables the Tx and Rx outputs, disables the charge pumps, and places the IC in a low current (35A) mode. The ISL3333 is a QFN packaged device that includes two additional user selectable, lower speed and edge rate options for EMI sensitive designs, or to allow longer bus lengths. It also features a logic supply pin (VL) that sets the VOH level of logic outputs, and the switching points of logic inputs, to be compatible with another supply voltage in mixed voltage systems. The QFN also adds RS-232 mode Tx EN pins (DEN), and active low Rx enable pins (RXEN) to increase design flexibility. In RS-485 applications, active low Rx enable pins allow Tx/Rx direction control, via a single signal per port, by connecting the corresponding DE and RXEN pins together. For a single port version of these devices, please see the ISL3330, ISL3331 data sheet.
Features
* 15kV (HBM) ESD Protected Bus Pins (RS-232 or RS-485) * Operates From a Single 3.3V Supply * Two Independent Ports, Each User Selectable for RS-232 (2 Transceivers) or RS-485/RS-422 (1 Transceiver) * True Flow-Through Pinouts Simplify Board Layouts * Pb-free (RoHS compliant) * Full Failsafe (Open/Short) Rx in RS-485/422 Mode * Loopback Mode Facilitates Board Self Test Functions * User Selectable RS-485 Data Rates (ISL3333 Only) - Fast Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Mbps - Slew Rate Limited. . . . . . . . . . . . . . . . . . . . . . . 460kbps - Slew Rate Limited. . . . . . . . . . . . . . . . . . . . . . . 115kbps * Fast RS-232 Data Rate . . . . . . . . . . . . . . . Up to 400kbps * RS-232 Tx and Rx Enable Pins (ISL3333 Only) * Small Charge Pump Caps . . . . . . . . . . . . . . . . . 4 x 0.1F * Low Current Shutdown Mode. . . . . . . . . . . . . . . . . . .35A * QFN Package Saves Board Space (ISL3333 Only) * Logic Supply Pin (VL) Eases Operation in Mixed Supply Systems (ISL3333 Only)
Applications
* Gaming Applications (e.g., Slot Machines) * Single Board Computers * Factory Automation * Security Networks * Industrial/Process Control Networks * Level Translators (e.g., RS-232 to RS-422) * Point of Sale Equipment * Dual Channel RS-485 Interfaces
TABLE 1. SUMMARY OF FEATURES NO. OF PART NUMBER PORTS PACKAGE OPTIONS ISL3332 ISL3333 2 2 28 Ld SSOP RS-485 DATA RATE (bps) 20M RS-232 DATA RATE (kbps) VL PIN? 400 400 NO YES RS-232 Tx ENABLE? NO YES ACTIVE H or L LOW POWER Rx ENABLE? SHUTDOWN? NONE L YES YES
40 Ld QFN (6 x 6mm) 20M, 460k, 115k
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright (c) Intersil Americas Inc. 2008. All Rights Reserved. All other trademarks mentioned are the property of their respective owners.
ISL3332, ISL3333 Ordering Information
PART NUMBER (NOTE) ISL3332IAZ* ISL3333IRZ* PART MARKING 3332 IAZ 3333 IRZ TEMP. RANGE (C) -40 to +85 -40 to +85 PACKAGE (Pb-Free) 28 Ld SSOP 40 Ld QFN PKG. DWG. # M28.209 L40.6x6
*Add "-T" suffix for tape and reel. Please refer to TB347 for details on reel specifications. NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
Pinouts
ISL3332 (28 LD SSOP) TOP VIEW
C1NC NC C1+ 1 C1- 2 V+ 3 A1 4 B1 5 Y1 6 Z1 7 SEL1 8 SEL2 9 Z2 10 Y2 11 B2 12 A2 13 GND 14 28 C2+ 27 C226 VCC 25 RB1 24 RA1 23 DZ1/DE1 22 DY1 21 LB 20 ON/OFF 19 DY2 18 DZ2/DE2 17 RA2 16 RB2 15 VY2 B2 V+ A1 B1 Y1 Z1 SEL1 SEL2 Z2 1 2 3 4 5 6 7 8 9 10 11 A2 12 DEN1 13 SPA 14 SPB 15 GND 16 GND 17 RXEN1 18 RXEN2 19 V20 DEN2 40 39 38 37 36 35 34 33 32 31 30 RB1 29 RA1 28 DZ1/DE1 27 DY1 26 LB 25 ON/OFF 24 DY2 23 DZ2/DE2 22 RA2 21 RB2
ISL3333 (40 LD QFN) TOP VIEW
VCC C1+ C2+ C2NC NC VL
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FN6362.0 May 27, 2008
ISL3332, ISL3333
TABLE 2. ISL3332 FUNCTION TABLE INPUTS SEL1 or 2 0 X 1 1 NOTE: 1. Charge pumps are off if SEL1 = SEL2 = 1, or if ON/OFF = 0. If ON = 1, and either port is programmed for RS-232 mode, then the charge pumps are on. ON/OFF 1 0 1 1 DE 1 or 2 N.A. X 0 1 RECEIVER OUTPUTS RA ON High-Z ON ON RB ON High-Z High-Z * High-Z * DRIVER OUTPUTS Y ON High-Z High-Z ON Z ON High-Z High-Z ON CHARGE PUMPS (NOTE 1) ON OFF OFF OFF
MODE RS-232 Shutdown RS-485 RS-485
ISL3332 Truth Tables (FOR EACH PORT)
RS-232 TRANSMITTING MODE INPUTS SEL1 or 2 ON/OFF 0 0 0 0 0 1 1 1 1 0 DY 0 0 1 1 X DZ 0 1 0 1 X OUTPUTS Y 1 1 0 0 High-Z Z 1 0 1 0 High-Z RS-485 RECEIVING MODE OUTPUT A 0 0 1 1 Open X B 0 1 0 1 Open X RA 1 1 0 0 1 High-Z RB 1 0 1 0 1 High-Z INPUTS SEL1 or 2 ON/OFF 1 1 1 1 1 1 1 0 B-A -40mV -200mV Open or Shorted together X OUTPUT RA 1 0 1 High-Z RB * High-Z High-Z High-Z High-Z RS-485 TRANSMITTING MODE INPUTS SEL1 or 2 ON/OFF 1 1 1 1 1 1 1 0 DE1 or 2 1 1 0 X DY 0 1 X X OUTPUTS Y 1 0 High-Z High-Z Z 0 1 High-Z High-Z
RS-232 RECEIVING MODE INPUTS SEL1 or 2 ON/OFF 0 0 0 0 0 0 1 1 1 1 1 0
* Internally pulled high through a 40k resistor.
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FN6362.0 May 27, 2008
ISL3332, ISL3333
TABLE 3. ISL3333 FUNCTION TABLE INPUTS SEL1 or 2 ON/OFF 0 0 0 0 X 1 1 1 1 1 1 1 1 1 1 NOTE: 2. Charge pumps are off if SEL1 = SEL2 = 1, or if ON/OFF = 0. If ON = 1, and either port is programmed for RS-232 mode, then the charge pumps are on. 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 SPA X X X X X X 0 0 1 1 X 0 0 1 1 SPB X X X X X X 0 1 0 1 X 0 1 0 1 RXEN 1 or 2 0 0 1 1 X 0 0 0 0 0 1 1 1 1 1 DEN 1 or 2 DE 1 or 2 0 1 0 1 X N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. X 0 1 1 1 1 0 1 1 1 1 RECEIVER OUTPUTS RA ON ON High-Z High-Z High-Z ON ON ON ON ON RB ON ON High-Z High-Z High-Z DRIVER OUTPUTS Y High-Z ON High-Z ON High-Z Z High-Z ON High-Z ON High-Z High-Z ON ON ON ON High-Z ON ON ON ON DRIVER CHARGE DATA RATE PUMPS (NOTE 2) (Mbps) ON ON ON ON OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF 0.46 0.46 0.46 0.46 N.A. N.A. 0.46 0.115 20 20 N.A. 0.46 0.115 20 20
MODE RS-232 RS-232 RS-232 RS-232 Shutdown RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485
High-Z * High-Z High-Z * High-Z * High-Z * High-Z * ON ON ON ON
High-Z High-Z * High-Z High-Z High-Z * High-Z High-Z * High-Z High-Z * High-Z High-Z * ON ON ON ON
ISL3333 Truth Tables (FOR EACH PORT)
RS-232 TRANSMITTING MODE INPUTS SEL1 or 2 ON/OFF DEN1 or 2 0 0 0 0 0 0 1 1 1 1 1 0 1 1 1 1 0 X DY 0 0 1 1 X X DZ 0 1 0 1 X X OUTPUTS Y 1 1 0 0 Z 1 0 1 0 1 1 1 1 1 0
RS-485 TRANSMITTING MODE INPUTS SEL1 ON/ DE or 2 OFF 1 or 2 SPA SPB 1 1 1 1 1 1 1 0 X 0 0 1 X X 0 1 X X X DY 0/1 0/1 0/1 X X OUTPUTS Y 1/0 1/0 1/0 Z 0/1 0/1 0/1 DATA RATE Mbps 0.46 0.115 20 N.A. N.A.
High-Z High-Z High-Z High-Z
High-Z High-Z High-Z High-Z
RS-232 RECEIVING MODE INPUTS RXEN 1 or 2 SEL1 or 2 ON/OFF 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 1 X A 0 0 1 1 Open X X B 0 1 0 1 Open X X OUTPUT RA 1 1 0 0 1 RB 1 0 1 0 1 1 1 1 0 SEL1 or 2 1 1 1
RS-485 RECEIVING MODE INPUTS ON/OFF 1 1 1 RXEN 1 or 2 0 0 0 1 X B-A -40mV -200mV Open or Shorted together X X OUTPUT RA 1 0 1 RB * High-Z High-Z High-Z
High-Z High-Z High-Z High-Z
High-Z High-Z High-Z High-Z
* Internally pulled high through a 40k resistor.
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FN6362.0 May 27, 2008
ISL3332, ISL3333 Pin Descriptions
PIN GND LB NC ON/OFF RXEN SEL VCC VL DEN A MODE BOTH BOTH BOTH BOTH BOTH BOTH BOTH BOTH Ground connection. Enables loopback mode when low. Internally pulled-high. No Connection. If either port is in RS-232 mode, a low on ON/OFF disables the charge pumps. In either mode, a low disables all the outputs, and places the device in low power shutdown. Internally pulled-high. ON = 1 for normal operation. Active low receiver output enable. The corresponding port's Rx is enabled when RXEN is low; Rx is high impedance when RXEN is high. Internally pulled low. (QFN only) Interface Mode Select input. High puts corresponding port in RS-485 Mode, while a low puts it in RS-232 Mode. System power supply input (3.3V). Logic-Level Supply. All TTL/CMOS inputs and outputs are powered by this supply. QFN logic input pins that are externally tied high in an application, should use the VL supply for the high voltage level. (QFN only) FUNCTION
RS-232 Active high driver output enable. The corresponding port's 232 mode drivers are enabled when DEN is high; drivers are disabled when DEN is low. Internally pulled high. (QFN only). RS-232 Receiver input with 15kV ESD protection. A low on A forces RA high; A high on A forces RA low. RS-485 Inverting receiver input with 15kV ESD protection.
B
RS-232 Receiver input with 15kV ESD protection. A low on B forces RB high; A high on B forces RB low. RS-485 Noninverting receiver input with 15kV ESD protection.
DY
RS-232 Driver input. A low on DY forces output Y high. Similarly, a high on DY forces output Y low. RS-485 Driver input. A low on DY forces output Y high and output Z low. Similarly, a high on DY forces output Y low and output Z high.
DZ / DE
RS-232 Driver input. A low on DZ forces output Z high. Similarly, a high on DZ forces output Z low. RS-485 Driver output enable (DE). The driver outputs, Y and Z, are enabled by bringing DE high. They are high impedance when DE is low. Internally pulled high when port selected for RS-485 mode.
RA
RS-232 Receiver output. RS-485 Receiver output: If B > A by at least -40mV, RA is high; If B < A by -200mV or more, RA is low; RA = High if A and B are unconnected (floating) or shorted together (i.e., full fail-safe).
RB
RS-232 Receiver output. RS-485 Not used. Internally pulled-high, and unaffected by RXEN.
Y
RS-232 Driver output with 15kV ESD protection. RS-485 Inverting driver output with 15kV ESD protection.
Z
RS-232 Driver output with 15kV ESD protection. RS-485 Noninverting driver output with 15kV ESD protection.
SP C1+ C1C2+ C2V+ V-
RS-485 Speed control. Internally pulled-high. (QFN only) RS-232 External capacitor (voltage doubler) is connected to this lead. Not needed if both ports in RS-485 Mode. RS-232 External capacitor (voltage doubler) is connected to this lead. Not needed if both ports in RS-485 Mode. RS-232 External capacitor (voltage inverter) is connected to this lead. Not needed if both ports in RS-485 Mode. RS-232 External capacitor (voltage inverter) is connected to this lead. Not needed if both ports in RS-485 Mode. RS-232 Internally generated positive RS-232 transmitter supply (+5.5V). C3 not needed if both ports in RS-485 Mode. RS-232 Internally generated negative RS-232 transmitter supply (-5.5V). C4 not needed if both ports in RS-485 Mode.
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FN6362.0 May 27, 2008
ISL3332, ISL3333 Typical Operating Circuits
RS-232 MODE WITHOUT LOOPBACK
+3.3V + +3.3V 0.1F 1 + 2 28 + 27 C1+ C1C2+ C2V- 15 26 VCC V+ 3 + C3 0.1F C4 0.1F + RA1 C1 0.1F C2 0.1F + 2 28 + 27 4 5k B1 5 5k LB Rx Y1 6 D 22 DY1 DZ1 GND VCC R 25 +
RS-232 MODE WITH LOOPBACK
0.1F 1 C1+ C1C2+ C2R 24 RA1
26 VCC V+ 3 + C3 0.1F C4 0.1F +
C1 0.1F C2 0.1F
V- 15
A1
4 5k 5 5k
R
24
A1
B1
R
25 RB1 RXEN1 (QFN ONLY) 22
RB1
Y1
6
D
DY1 DZ1 VCC VCC
Z1 VCC
7 DEN1 (QFN ONLY) 8 SEL1 GND
D LB ON/OFF 14
23 21 20
Z1 VCC
7 DEN1 (QFN ONLY) 8 SEL1 GND
D LB ON/OFF 14
23 21 20
NOTE: PINOUT FOR SSOP SAME FOR PORT 2.
NOTE: PINOUT FOR SSOP SAME FOR PORT 2.
RS-485 MODE WITHOUT LOOPBACK
+3.3V + 0.1F 1 + 2 28 + 27 4 5 R 24 C1+ C1C2+ C226 VCC V+ 3 + C3 0.1F C4 0.1F + RA1 C1 0.1F C2 0.1F
RS-485 MODE WITH LOOPBACK
+3.3V
+
0.1F 1 C1+ C1C2+ C2-
26 VCC V+ 3 + C3 0.1F C4 0.1F + RA1
C1 0.1F C2 0.1F
+ 2 28 + 27 4 5
V- 15
V- 15
A1 B1
A1 B1
R
24
RXEN1 (QFN ONLY) 6 7 D 25 22 RB1 DY1 Y1 Z1 25 6 22 7 D RB1 DY1 LB Rx
Y1 Z1
23 VCC VCC 8
DE1 LB SEL1 GND 14 ON/OFF
21 VCC 20 VCC
23 VCC VCC 8
DE1 LB SEL1 GND 14 ON/OFF
21 GND 20 VCC
NOTE: PINOUT FOR SSOP SAME FOR PORT 2.
NOTE: PINOUT FOR SSOP SAME FOR PORT 2.
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FN6362.0 May 27, 2008
ISL3332, ISL3333
Absolute Maximum Ratings (TA = +25C)
VCC to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V VL (QFN Only) . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to VCC + 0.5V Input Voltages All Except A,B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to 7V Input/Output Voltages A, B (Any Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . -25V to +25V Y, Z (Any Mode, Note 3) . . . . . . . . . . . . . . . . . . . -12.5V to +12.5V RA, RB (non-QFN Package). . . . . . . . . . . . -0.5V to (VCC + 0.5V) RA, RB (QFN Package) . . . . . . . . . . . . . . . . -0.5V to (VL + 0.5V) Output Short Circuit Duration Y, Z, RA, RB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indefinite ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table
Thermal Information
Thermal Resistance (Typical)
JA (C/W) JC (C/W)
28 Ld SSOP Package (Note 5) . . . . . . 60 N/A 40 Ld QFN Package (Notes 4, 6). . . . . 31 2.5 Maximum Junction Temperature (Plastic Package) . . . . . . . +150C Maximum Storage Temperature Range . . . . . . . . . .-65C to +150C Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp
Operating Conditions
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . .-40C to +85C
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty.
NOTES: 3. One output at a time, IOUT 100mA for 10 mins. 4. JA is measured in free air with the component mounted on a high effective thermal conductivity test board with "direct attach" features. See Tech Brief TB379. 5. JA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details. 6. For JC, the "case temp" location is the center of the exposed metal pad on the package underside.
Electrical Specifications
Test Conditions: VCC = 3.15V to 3.45V, C1 - C4 = 0.1F, VL = VCC (for QFN only); Unless Otherwise Specified. Typicals are at VCC = 3.3V, TA =+25C (Note 7) SYMBOL TEST CONDITIONS TEMP MIN (C) (Note 11) TYP MAX (Note 11) UNITS
PARAMETER
DC CHARACTERISTICS - RS-485 DRIVER (SEL = VCC) Driver Differential VOUT (no load) Driver Differential VOUT (with load) VOD1 VOD2 VOD3 Change in Magnitude of Driver Differential VOUT for Complementary Output States Driver Common-Mode VOUT Change in Magnitude of Driver Common-Mode VOUT for Complementary Output States Driver Short-Circuit Current, VOUT = High or Low Driver Three-State Output Leakage Current (Y, Z) VOD R = 50 (RS-422) (Figure 1) R = 27 (RS-485) (Figure 1) RD = 60, R = 375, VCM = -7V to 12V (Figure 1) R = 27 or 50 (Figure 1) Full Full Full Full Full 2 1.5 1.5 2.3 2 0.01 VCC 5 5 0.2 V V V V V
VOC VOC
R = 27 or 50 (Figure 1) R = 27 or 50 (Figure 1)
Full Full
-
0.01
3.0 0.2
V V
IOS IOZ
-7V (VY or VZ) 12V (Note 8) Outputs Disabled, VCC = 0V or 3.6V VOUT = 12V VOUT = -7V
Full Full Full
35 -200
-
250 200 -
mA A A
DC CHARACTERISTICS - RS-232 DRIVER (SEL = GND) Driver Output Voltage Swing Driver Output Short-Circuit Current VO IOS VIH1 VIH2 VIH3 VIH4 VIH5 All TOUTS Loaded with 3k to Ground VOUT = 0V VL = VCC if QFN 2.7V VL < 3.0V (QFN Only) 2.3V VL < 2.7V (QFN Only) 1.6V VL < 2.3V (QFN Only) 1.2V VL < 1.6V (QFN Only) Full Full 5.0 -60 60 V mA
DC CHARACTERISTICS - LOGIC PINS (i.e., DRIVER AND CONTROL INPUT PINS) Input High Voltage Full Full Full Full 25 2.2 2 1.6 0.7*VL 0.7*VL V V V V V
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FN6362.0 May 27, 2008
ISL3332, ISL3333
Electrical Specifications
Test Conditions: VCC = 3.15V to 3.45V, C1 - C4 = 0.1F, VL = VCC (for QFN only); Unless Otherwise Specified. Typicals are at VCC = 3.3V, TA =+25C (Note 7) (Continued) SYMBOL VIL1 VIL2 VIL3 VIL4 VIL5 VIL6 Input Current IIN1 IIN2 Receiver Differential Threshold Voltage Receiver Input Hysteresis Receiver Input Current (A, B) VTH VTH IIN RIN TEST CONDITIONS VL = VCC if QFN VL 2.7V (QFN Only) 2.3V VL < 2.7V (QFN Only) 1.6V VL < 2.3V (QFN Only) 1.3V VL < 1.6V (QFN Only) 1.2V VL < 1.3V (QFN Only) Pins Without Pull-ups or Pull-downs LB, ON/OFF, DE (SP, RXEN, DEN, if QFN) -7V VCM 12V, Full Failsafe VCM = 0V VCC = 0V or 3.0 to 3.6V VIN = 12V VIN = -7V Receiver Input Resistance -7V VCM 12V, VCC = 0 (Note 9) or 3.0V VCC 3.6V TEMP MIN (C) (Note 11) Full Full Full Full 25 25 Full Full -2 -25 TYP 0.35*VL 0.25*VL MAX (Note 11) UNITS 0.8 0.8 0.7 0.35*VL 2 25 V V V V V V A A
PARAMETER Input Low Voltage
DC CHARACTERISTICS - RS-485 RECEIVER INPUTS (SEL = VCC) Full 25 Full Full Full -0.2 -0.64 15 35 -0.04 0.8 V mV mA mA k
DC CHARACTERISTICS - RS-232 RECEIVER INPUTS (SEL = GND) Receiver Input Voltage Range Receiver Input Threshold Receiver Input Hysteresis Receiver Input Resistance VIN VIL VIH VTH RIN VOH1 VOH2 VOH3 VOH4 Receiver Output Low Voltage Receiver Short-Circuit Current Receiver Three-State Output Current Unused Receiver (RB) Pull-Up Resistance VOL IOSR IOZR ROBZ VIN = 15V, VCC Powered Up (Note 9) IO = -1.5mA (VL = VCC if QFN) IO = -100A, VL 1.2V (QFN Only) IO = -500A, VL = 1.5V (QFN Only) IO = -150A, VL = 1.2V (QFN Only) IO = 5mA 0V VO VCC Output Disabled, 0V VO VCC (or VL for QFN) ON/OFF = VCC, SELX = VCC (RS-485 Mode) Full Full Full 25 Full -25 2.4 3 1.1 1.6 0.5 5 25 0.8 7 V V V V k
DC CHARACTERISTICS - RECEIVER OUTPUTS (485 OR 232 MODE) Receiver Output High Voltage Full Full Full Full Full Full Full 25 VCC-0.4 VL-0.1 1.2 1.0 7 0.2 40 0.4 85 10 V V V V V mA A k
POWER SUPPLY CHARACTERISTICS No-Load Supply Current, (Note 7) ICC232 ICC485 Shutdown Supply Current SEL1 or SEL2 = GND, LB = ON/OFF = VCC SEL 1 & 2 = LB = DE = ON/OFF = VCC Full Full Full Full Full 3.7 1.6 45 35 60 7 5 100 80 160 mA mA A A A
ISHDN232 ON/OFF = SELX = GND, LB = VCC, (SPX = VL, DENX = GND if QFN) ISHDN485 ON/OFF = DEX = GND, SELX = LB = VCC, (SPX = GND, DENX = VL if QFN) SSOP QFN
ESD CHARACTERISTICS Bus Pins (A, B, Y, Z) Any Mode All Other Pins Human Body Model Human Body Model Machine Model 25 25 25 15 2.5 200 kV kV V
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FN6362.0 May 27, 2008
ISL3332, ISL3333
Electrical Specifications
Test Conditions: VCC = 3.15V to 3.45V, C1 - C4 = 0.1F, VL = VCC (for QFN only); Unless Otherwise Specified. Typicals are at VCC = 3.3V, TA =+25C (Note 7) (Continued) SYMBOL TEST CONDITIONS CL 15pF CL 2500pF TEMP MIN (C) (Note 11) TYP MAX (Note 11) UNITS
PARAMETER Driver Output Transition Region Slew Rate Driver Output Transition Time Driver Propagation Delay Driver Propagation Delay Skew Driver Enable Time (QFN Only) Driver Disable Time (QFN Only) Driver Enable Time from Shutdown Driver Maximum Data Rate Receiver Propagation Delay
RS-232 DRIVER AND RECEIVER SWITCHING CHARACTERISTICS (SEL = GND, ALL VERSIONS AND SPEEDS) SR RL = 3k, Measured From 3V to -3V or -3V to 3V Full Full Full Full Full tDPHL - tDPLH (Figure 6) CL = 1000pF RL = 5k, Measured at VOUT = 3V, CL = 30pF VOUT = 3.0V, CL = 1000pF RL = 3k, CL = 500pF, One Transmitter Switching on Each Port CL = 15pF (Figure 7) tRPHL - tRPLH (Figure 7) CL = 15pF QFN Only, CL = 15pF, SW = VCC QFN Only, CL = 15pF, SW = GND QFN Only, CL = 15pF, SW = VCC QFN Only, CL = 15pF, SW = GND CL = 15pF, SW = VCC CL = 15pF, SW = GND Full 25 25 25 Full Full Full Full Full Full Full Full Full 25 25 4 0.22 250 0.46 20 9 1.2 1 1.2 300 1500 500 25 400 40 58 18 2 18 18 22 22 60 20 30 3.1 2 2 450 120 120 40 V/s V/s s s s ns ns ns s kbps ns ns ns Mbps ns ns ns ns ns ns
tr, tf tDPHL tDPLH tDSKEW tDEN tDDIS tDENSD DRD tRPHL tRPLH tRSKEW DRR tZL tZH tLZ tHZ tZLSHDN tZHSHDN
RL = 3k, CL = 2500pF, 10% - 90% RL = 3k, CL = 1000pF (Figure 6)
Receiver Propagation Delay Skew Receiver Maximum Data Rate Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable from Output Low Receiver Disable from Output High Receiver Enable from Shutdown to Output Low Receiver Enable from Shutdown to Output High
RS-485 DRIVER SWITCHING CHARACTERISTICS (FAST DATA RATE (20Mbps), SEL = VCC, ALL VERSIONS (SPA = VCC if QFN)) Driver Differential Input to Output Delay Driver Output Skew Driver Differential Rise or Fall Time Driver Enable to Output Low Driver Enable to Output High Driver Disable from Output Low Driver Disable from Output High Driver Enable from Shutdown to Output Low Driver Enable from Shutdown to Output High Driver Maximum Data Rate tDLH, tDHL RDIFF = 54, CL = 100pF (Figure 2) tSKEW tR, tF tZL tZH tLZ tHZ RDIFF = 54, CL = 100pF (Figure 2) RDIFF = 54, CL = 100pF, (Figure 2) CL = 100pF, SW = VCC (Figure 3) CL = 100pF, SW = GND (Figure 3) CL = 15pF, SW = VCC (Figure 3) CL = 15pF, SW = GND (Figure 3) Full Full Full Full Full Full Full Full Full Full 10 3 20 20 2 20 28 35 30 30 100 290 35 35 10 30 60 60 60 60 250 375 ns ns ns ns ns ns ns ns ns Mbps
tZL(SHDN) RL = 500, CL = 100pF, SW = VCC (Figure 3) tZH(SHDN) RL = 500, CL = 100pF, SW = GND (Figure 3) fMAX RDIFF = 54, CL = 100pF (Figure 2)
RS-485 DRIVER SWITCHING CHARACTERISTICS (MEDIUM DATA RATE (460kbps, QFN ONLY), SEL = VCC, SPA = SPB= GND) Driver Differential Input to Output Delay Driver Output Skew Driver Differential Rise or Fall Time Driver Enable to Output Low tDLH, tDHL RDIFF = 54, CL = 100pF (Figure 2) tSKEW tR, tF tZL RDIFF = 54, CL = 100pF (Figure 2) RDIFF = 54, CL = 100pF (Figure 2) CL = 100pF, SW = VCC (Figure 3) Full Full Full Full 200 300 500 10 660 42 1000 150 1100 100 ns ns ns ns
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FN6362.0 May 27, 2008
ISL3332, ISL3333
Electrical Specifications
Test Conditions: VCC = 3.15V to 3.45V, C1 - C4 = 0.1F, VL = VCC (for QFN only); Unless Otherwise Specified. Typicals are at VCC = 3.3V, TA =+25C (Note 7) (Continued) SYMBOL tZH tLZ tHZ TEST CONDITIONS CL = 100pF, SW = GND (Figure 3) CL = 15pF, SW = VCC (Figure 3) CL = 15pF, SW = GND (Figure 3) TEMP MIN (C) (Note 11) Full Full Full Full Full Full 460 TYP 350 30 30 2000 MAX (Note 11) UNITS 450 60 60 500 750 ns ns ns ns ns kbps
PARAMETER Driver Enable to Output High Driver Disable from Output Low Driver Disable from Output High Driver Enable from Shutdown to Output Low Driver Enable from Shutdown to Output High Driver Maximum Data Rate
tZL(SHDN) RL = 500, CL = 100pF, SW = VCC (Figure 3) tZH(SHDN) RL = 500, CL = 100pF, SW = GND (Figure 3) fMAX RDIFF = 54, CL = 100pF (Figure 2)
RS-485 DRIVER SWITCHING CHARACTERISTICS (SLOW DATA RATE (115kbps, QFN ONLY), SEL = VCC, SPA = GND, SPB= VCC) Driver Differential Input to Output Delay Driver Output Skew Driver Differential Rise or Fall Time Driver Enable to Output Low Driver Enable to Output High Driver Disable from Output Low Driver Disable from Output High Driver Enable from Shutdown to Output Low Driver Enable from Shutdown to Output High Driver Maximum Data Rate tDLH, tDHL RDIFF = 54, CL = 100pF (Figure2) tSKEW tR, tF tZL tZH tLZ tHZ RDIFF = 54, CL = 100pF (Figure2) RDIFF = 54, CL = 100pF (Figure 2) CL = 100pF, SW = VCC (Figure 3) CL = 100pF, SW = GND (Figure 3) CL = 15pF, SW = VCC (Figure 3) CL = 15pF, SW = GND (Figure 3) Full Full Full Full Full Full Full Full Full Full 800 1000 115 1600 250 1700 45 900 35 25 800 2500 500 3100 100 1200 60 60 800 1500 ns ns ns ns ns ns ns ns ns kbps
tZL(SHDN) RL = 500, CL = 100pF, SW = VCC (Figure 3) tZH(SHDN) RL = 500, CL = 100pF, SW = GND (Figure 3) fMAX RDIFF = 54, CL = 100pF (Figure 2)
RS-485 RECEIVER SWITCHING CHARACTERISTICS (SEL = VCC, ALL VERSIONS AND SPEEDS) Receiver Input to Output Delay Receiver Skew | tPLH - tPHL | Receiver Maximum Data Rate Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable from Output Low Receiver Disable from Output High Receiver Enable from Shutdown to Output Low Receiver Enable from Shutdown to Output High NOTES: 7. All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified. 8. Supply current specification is valid for loaded drivers when DE = 0V (RS-485 mode) or DEN = 0V (RS-232 mode). 9. Applies to peak current. See "Typical Performance Curves" for more information. 10. RIN defaults to RS-485 mode (>15k) when the device is unpowered (VCC = 0V), or in SHDN, regardless of the state of the SEL inputs. 11. Parameters with MIN and/or MAX limits are 100% tested at +25C, unless otherwise specified. Temperature limits established by characterization and are not production tested. tPLH, tPHL (Figure 4) tSKEW fMAX tZL tZH tLZ tHZ tZLSHDN tZHSHDN QFN Only, CL = 15pF, SW = VCC (Figure 5) QFN Only, CL = 15pF, SW = GND (Figure5) QFN Only, CL = 15pF, SW = VCC (Figure 5) QFN Only, CL = 15pF, SW = GND (Figure 5) CL = 15pF, SW = VCC (Figure 5) CL = 15pF, SW = GND (Figure 5) (Figure 4) Full Full Full Full Full Full Full Full Full 20 20 45 3 40 20 20 20 20 500 500 70 10 60 60 60 60 900 900 ns ns Mbps ns ns ns ns ns ns
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FN6362.0 May 27, 2008
ISL3332, ISL3333 Test Circuits and Waveforms
R VCC DE DY Y D Z R VOC RD VOD
FIGURE 1. RS-485 DRIVER VOD AND VOC TEST CIRCUIT
3V DY CL = 100pF Y D Z SIGNAL GENERATOR OUT (Y) tDLH DIFF OUT (Z - Y) tR SKEW = |tPLH (Y or Z) - tPHL (Z or Y)| 90% 10% 0V RDIFF CL = 100pF tPHL 50% tDHL 0V 90% 10% tF +VOD -VOD tPLH VOH 50% VOL OUT (Z) 50% 50% VOL 1.5V 1.5V 0V tPLH tPHL VOH
VCC
DE DY
FIGURE 2A. TEST CIRCUIT
FIGURE 2B. MEASUREMENT POINTS
FIGURE 2. RS-485 DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES
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FN6362.0 May 27, 2008
ISL3332, ISL3333 Test Circuits and Waveforms (Continued)
DE DY SIGNAL GENERATOR Y D Z CL tZH(SHDN) FOR SHDN TESTS, SWITCH ON/OFF RATHER THAN DE OUT (Y, Z) tZH OUTPUT HIGH 2.3V tHZ VOH - 0.5V VOH 0V tZL tZL(SHDN) OUT (Y, Z) 2.3V OUTPUT LOW tLZ VCC VOL + 0.5V V OL 500 SW VCC GND ENABLED DE (ON/OFF FOR SHDN) 1.5V 1.5V 0V 3V
PARAMETER tHZ tLZ tZH tZL tZH(SHDN) tZL(SHDN)
ON/DE 1/1/1/1/-/1 -/1
OUTPUT Y/Z Y/Z Y/Z Y/Z Y/Z Y/Z
DY 0/1 1/0 0/1 1/0 0/1 1/0
SW GND VCC GND VCC GND VCC
CL (pF) 15 15 100 100 100 100 FIGURE 3B. MEASUREMENT POINTS
FIGURE 3A. TEST CIRCUIT
FIGURE 3. RS-485 DRIVER ENABLE AND DISABLE TIMES
RXEN (QFN ONLY) 0V A B R 15pF RA B 0V tPLH 0V
+1.5V -1.5V tPHL VCC RA 1.5V 1.5V 0V
SIGNAL GENERATOR
FIGURE 4A. TEST CIRCUIT
FIGURE 4B. MEASUREMENT POINTS
FIGURE 4. RS-485 RECEIVER PROPAGATION DELAY
RXEN (QFN ONLY) A R SIGNAL GENERATOR B RA 1k SW 15pF VCC GND
ON/OFF (FOR SHDN TESTS)
3V 1.5V ENABLED 0V 3V 1.5V 0V
RXEN (QFN ONLY)
1.5V
FOR SHDN TESTS, SWITCH ON/OFF RATHER THAN RXEN
tZH tZH(SHDN)
OUTPUT HIGH 1.5V
tHZ VOH - 0.5V VOH 0V
PARAMETER tHZ (QFN Only) tLZ (QFN Only) tZH (QFN Only) tZL (QFN Only) tZH(SHDN) tZL(SHDN)
ON/RXEN 1/1/1/1/-/0 -/0
B +1.5V -1.5V +1.5V -1.5V +1.5V -1.5V
SW GND VCC GND VCC GND VCC
tZL tZL(SHDN) RA 1.5V OUTPUT LOW tLZ RA
VCC VOL + 0.5V V
OL
FIGURE 5A. TEST CIRCUIT
FIGURE 5B. MEASUREMENT POINTS
FIGURE 5. RS-485 RECEIVER ENABLE AND DISABLE TIMES
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ISL3332, ISL3333 Test Circuits and Waveforms (Continued)
VCC DEN (QFN ONLY) DY,Z Y, Z CL tDPHL RL OUT (Y,Z) 0V 0V VOSKEW = |tDPHL - tDPLH| 3V DY,Z 1.5V 1.5V 0V tDPLH VO+
D
SIGNAL GENERATOR
FIGURE 6A. TEST CIRCUIT
FIGURE 6B. MEASUREMENT POINTS
FIGURE 6. RS-232 DRIVER PROPAGATION DELAY AND TRANSITION TIMES
RXEN (QFN ONLY) A, B RA, RB CL = 15pF
3V A, B 50% 50% 0V tRPHL RA, RB SKEW = |tRPHL - tRPLH| tRPLH VOH 50% 50% VOL
R
SIGNAL GENERATOR
FIGURE 7A. TEST CIRCUIT
FIGURE 7B. MEASUREMENT POINTS
FIGURE 7. RS-232 RECEIVER PROPAGATION DELAY AND TRANSITION TIMES
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FN6362.0 May 27, 2008
ISL3332, ISL3333 Typical Application
RS-232 to RS-485 Converter
The ISL3332, ISL3333 are ideal for implementing a single IC 2-wire (Tx Data, Rx Data) protocol converter, because each port can be programmed for a different protocol. Figure 8 illustrates the simple connections to create a single transceiver RS-232 to RS-485 converter. Depending on the RS-232 data rate, using an RS-422 bus as an RS-232 "extension cord" can extend the transmission distance up to 4000' (1220m). A similar circuit on the other end of the cable completes the conversion to/from RS-232.
+3.3V C1 0.1F C2 0.1F + 0.1F 2 C128 C2+ + 27 C24 A1 5k 5 B1 5k NC RxD RS-232 OUT 6 Y1 7 Z1 8 VCC 9 SEL1 SEL2 ON/OFF 20 VCC + 1 C1+ 26 VCC V+ 3 +C3 0.1F C4 0.1F +
Detailed Description
Each of the two ISL333X ports supports dual protocols: RS-485/422, and RS-232. RS-485 and RS-422 are differential (balanced) data transmission standards for use in high speed (up to 20Mbps) networks, or long haul and noisy environments. The differential signaling, coupled with RS-485's requirement for an extended common mode range (CMR) of +12V to -7V make these transceivers extremely tolerant of ground potential differences, as well as voltages induced in the cable by external fields. Both of these effects are real concerns when communicating over the RS-485/422 maximum distance of 4000' (1220m). It is important to note that the ISL333X don't follow the RS-485 convention whereby the inverting I/O is labeled "B/Z", and the non inverting I/O is "A/Y". Thus, in the application diagrams below the 333X A/Y (B/Z) pins connect to the B/Z (A/Y) pins of the generic RS-485/RS-422 ICs. RS-422 is typically a point-to-point (one driver talking to one receiver on a bus), or a point-to-multipoint (multidrop) standard that allows only one driver and up to 10 receivers on each bus. Because of the one driver per bus limitation, RS-422 networks use a two bus, full duplex structure for bidirectional communication, and the Rx inputs and Tx outputs (no tri-state required) connect to different busses, as shown in Figure 10. Conversely, RS-485 is a true multipoint standard, which allows up to 32 devices (any combination of drivers- must be tri-statable - and receivers) on each bus. Now bidirectional communication takes place on a single bus, so the Rx inputs and Tx outputs of a port connect to the same bus lines, as shown in Figure 9. Each port set to RS-485 /422 mode includes one Rx and one Tx.RS-232 is a point-to-point, singled ended (signal voltages referenced to GND) communication protocol targeting fairly short (<150', 46m) and low data rate (<1Mbps) applications. Each port contains two transceivers (2 Tx and 2 Rx) in RS-232 mode. Protocol selection is handled via a logic pin (SELX) for each port.
V- 15 R R
NC TxD RS-232 IN
RA1 24 NC RB1 25
D D
DY1 22 DZ1 23
13 A2 RS-485 IN 12 B2 11 RS-485 OUT 10 Y2 Z2 D R
RA2 17
DY2 19 DE2 18
VCC
GND 14 NOTE: PINOUT FOR SSOP
FIGURE 8. SINGLE IC RS-232 TO RS-485 CONVERTER
GENERIC 1/2 DUPLEX 485 XCVR RO RE DE DI D 0.1F GND B/Z A/Y Y D Z GND B/Z A/Y RT RT GND D + GENERIC 1/2 DUPLEX 485 XCVR +5V + VCC R RO RE DE DI
+3.3V ISL333X VCC RA RXEN * Tx/Rx DE DY R B A + 0.1F
0.1F R +5V VCC
* QFN ONLY
FIGURE 9. TYPICAL HALF DUPLEX RS-485 NETWORK
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ISL3332, ISL3333
GENERIC 422 Rx (SLAVE) RO RE GENERIC FULL DUPLEX 422 XCVR (SLAVE) +5V R 0.1F VCC D Z Y A RA R B GND RT +5V VCC GND B A RT A B Z Y GND D DI 0.1F + + +3.3V ISL333X (MASTER) 1k OR NC DY DE + 0.1F
VCC R RO
FIGURE 10. TYPICAL RS-422 NETWORK
.
ISL333x Advantages
These dual protocol ICs offer many parametric improvements vs those offered on competing dual protocol devices. Some of the major improvements are: * 3.3V Supply Voltage - Eliminates the 5V supply that powers just the interface IC * 15kV Bus Pin ESD - Eases board level requirements * Full Failsafe RS-485 Rx - Eliminates bus biasing * Selectable RS-485 Data Rate - Up to 20Mbps, or slew rate limited for low EMI and fewer termination issues * High RS-232 Data Rate - >250kbps * Lower Tx and Rx Skews - Wider, consistent bit widths * Lower ICC - Max ICC is 2x to -4x lower than competition * Flow-Thru Pinouts - Tx, Rx bus pins on one side/logic pins on the other, for easy routing to connector/UART Packaging - Smaller (QFN) and Pb-free.
ON/OFF pin, or via the active low RXEN pins available on the QFN package option (see "ISL3333 Special Features" for more details).
Tx Features
RS-232 drivers invert and convert the standard TTL/CMOS levels from a UART, or controller serial port to RS-232 compliant levels (5V minimum). The Tx delivers these compliant output levels even at data rates of 400kbps, with loads of 500pF, and with one output in each port switching at this high rate. The drivers are designed for low skew (typically 12% of the 400kbps bit width), and are compliant to the RS-232 slew rate spec (4 to 30V/s) for a wide range of load capacitances. Tx inputs float if left unconnected, and may cause ICC increases. For the best results, connect unused inputs to GND. Tx outputs are short circuit protected, and incorporate a thermal SHDN feature to protect the IC in situations of severe power dissipation - see the RS-485 section for more details. All drivers disable in SHDN, or when the 3.3V power supply is off, and a port's drivers also disable via the corresponding DENX pin (see "ISL3333 Special Features" for more details) available on the QFN package option (see Tables 2 and 3 and the "Low Power Shutdown" section). The ISL3332's SHDN function is useful for disabling the outputs if both ports will always be disabled together (e.g., used as a four transceiver RS-232 port), and if it is acceptable for the Rx to be disabled as well.
RS-232 Mode
Rx Features
RS-232 receivers invert and convert RS-232 input levels (3V to 25V) to the standard TTL/CMOS levels required by a UART, ASIC, or controller serial port. Receivers are designed to operate at faster data rates than the drivers, and they feature very low skews (18ns) so the receivers contribute negligibly to bit width distortion. Inputs include the standards required 3k to 7k pull-down resistor, so unused inputs may be left unconnected. Rx inputs also have built-in hysteresis to increase noise immunity, and to decrease erroneous triggering due to slowly transitioning input signals. Rx outputs are short circuit protected, and are only tristatable when the entire IC is shutdown (SHDN) via the
Charge Pumps
The on-chip charge pumps create the RS-232 transmitter power supplies (typically +5.7/-5.3V) from a single supply as low as 3.15V, and are enabled only if either port is configured for RS-232 operation. The efficient design requires only four small 0.1F capacitors for the voltage doubler and inverter functions. By operating discontinuously (i.e., turning off as soon as V+ and V- pump up to the
FN6362.0 May 27, 2008
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ISL3332, ISL3333
nominal values), the charge pump contribution to RS-232 mode ICC is reduced significantly. Unlike competing devices that require the charge pump in RS-485 mode, disabling the charge pump saves power, and minimizes noise. If the application keeps both ports in RS-485 mode (e.g., a dedicated dual channel RS-485 interface), then the charge pump capacitors aren't even required. the Rx upper switching point at -40mV, thereby ensuring that the Rx recognizes a 0V differential as a high level. All the Rx outputs are short circuit protected, and are tri-state when the IC is forced into SHDN, but ISL3332 (SSOP) receiver outputs are not independently tri-statable. ISL3333 (QFN) receiver outputs are tri-statable via an active low RXEN input for each port (see "ISL3333 Special Features" for more details).
Data Rates and Cabling
Drivers operate at data rates up to 400kbps, and are guaranteed for data rates up to 250kbps. The charge pumps and drivers are designed such that one driver in each port can be operated at the rated load, and at 250kbps (see Figure 34). Figure 34 also shows that drivers can easily drive two to three thousand picofarads at data rates up to 250kbps, while still delivering compliant 5V output levels. Receivers operate at data rates up to 2Mbps. They are designed for a higher data rate to facilitate faster factory downloading of software into the final product, thereby improving the user's manufacturing throughput. Figures 37 and 38 illustrate driver and receiver waveforms at 250kbps, and 500kbps, respectively. For these graphs, one driver of each port drives the specified capacitive load, and a receiver in the port. RS-232 doesn't require anything special for cabling; just a single bus wire per transmitter and receiver, and another wire for GND. So an ISL333X RS-232 port uses a five conductor cable for interconnection. Bus terminations are not required, nor allowed, by the RS-232 standard.
Tx Features
The RS-485/RS-422 driver is a differential output device that delivers at least 1.5V across a 54 load (RS-485), and at least 2V across a 100 load (RS-422). The drivers feature low propagation delay skew to maximize bit widths, and to minimize EMI. To allow multiple drivers on a bus, the RS-485 spec requires that drivers survive worst case bus contentions undamaged. The ISL333X drivers meet this requirement via driver output short circuit current limits, and on-chip thermal shutdown circuitry. The output stages incorporate current limiting circuitry that ensures that the output current never exceeds the RS-485 spec, even at the common mode voltage range extremes of 12V and -7V. In the event of a major short circuit condition, devices also include a thermal shutdown feature that disables the drivers whenever the die temperature becomes excessive. This eliminates the power dissipation, allowing the die to cool. The drivers automatically re-enable after the die temperature drops about 15 degrees. If the contention persists, the thermal shutdown/re-enable cycle repeats until the fault is cleared. Receivers stay operational during thermal shutdown. RS-485 multi-driver operation also requires drivers to include tri-state functionality, so each port has a DE pin to control this function. If the driver is used in an RS-422 network, such that driver tri-state isn't required, then the DE pin can be left unconnected and an internal pull-up keeps it in the enabled state. Drivers are also tri-stated when the IC is in SHDN, or when the 3.3V power supply is off.
RS-485 Mode
Rx Features
RS-485 receivers convert differential input signals as small as 200mV, as required by the RS-485 and RS-422 standards, to TTL/CMOS output levels. The differential Rx provides maximum sensitivity, noise immunity, and common mode rejection. Per the RS-485 standard, receiver inputs function with common mode voltages as great as +12V and -7V, regardless of supply voltage, making them ideal for long networks where induced voltages are a realistic concern. Each RS-485/RS-422 port includes a single receiver (RA), and the unused Rx output (RB) is disabled but pulled high by an internal current source. The internal current source turns off in SHDN. Worst case receiver input currents are 20% lower than the 1 "unit load" (1mA) RS-485 limit, which translates to a 15k minimum input resistance. These receivers include a "full fail-safe" function that guarantees a high level receiver output if the receiver inputs are unconnected (floating), shorted together, or if the bus is terminated but undriven (i.e., differential voltage collapses to near zero due to termination). Failsafe with shorted, or terminated and undriven inputs is accomplished by setting
Speed Options
The ISL3332 (SSOP) has fixed, high slew rate driver outputs optimized for 20Mbps data rates. The ISL3333 (QFN) offers three user selectable data rate options: "Fast" for high slew rate and 20Mbps; "Medium" with slew rate limiting set for 460kbps; "Slow" with even more slew rate limiting for 115kbps operation. See the "Data Rate" and "Slew Rate Limited Data Rates" sections for more information. Receiver performance is the same for all three speed options.
Data Rate, Cables, and Terminations
RS-485/RS-422 are intended for network lengths up to 4000' (1220m), but the maximum system data rate decreases as the transmission length increases. Devices operating at the maximum data rate of 20Mbps are limited to maximum lengths of 20-100' (6-31m), while devices operating at or
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ISL3332, ISL3333
below 115kbps can operate at the maximum length of 4000' (1220m). Higher data rates require faster edges, so both the ISL333X versions offer an edge rate capable of 20Mbps data rates. The ISL3333 also offers two slew rate limited edge rates to minimize problems at slower data rates. Nevertheless, for the best jitter performance when driving long cables, the faster speed settings may be preferable, even at low data rates. See the "RS-485 Slew Rate Limited Data Rates" section for details. Twisted pair is the cable of choice for RS-485/RS-422 networks. Twisted pair cables tend to pick up noise and other electromagnetically induced voltages as common mode signals, which are effectively rejected by the differential receivers in these ICs. The preferred cable connection technique is "daisychaining", where the cable runs from the connector of one device directly to the connector of the next device, such that cable stub lengths are negligible. A "backbone" structure, where stubs run from the main backbone cable to each device's connector, is the next best choice, but care must be taken to ensure that each stub is electrically "short". See Table 4 for recommended maximum stub lengths for each speed option.
TABLE 4. RECOMMENDED STUB LENGTHS SPEED OPTION SLOW MED FAST MAXIMUM STUB LENGTH ft (m) 350-500 (107-152) 100-150 (30.5 - 46) 1-3 (0.3 - 0.9)
High ESD
All pins on the ISL333X include ESD protection structures rated at 2.5kV (HBM), which is good enough to survive ESD events commonly seen during manufacturing. But the bus pins (Tx outputs and Rx inputs) are particularly vulnerable to ESD events because they connect to an exposed port on the exterior of the finished product. Simply touching the port pins, or connecting a cable, can destroy an unprotected port. ISL333X bus pins are fitted with advanced structures that deliver ESD protection in excess of 15kV (HBM), without interfering with any signal in the RS-485 or the RS-232 range. This high level of protection may eliminate the need for board level protection, or at the very least will increase the robustness of any board level scheme.
Small Packages
Competing 3.3V dual protocol ICs are available only in a 28 Ld SSOP. The ISL3333's tiny 6x6mm QFN footprint is 80% smaller than the competing SSOP.
Flow Through Pinouts
Even the ISL333X pinouts are features, in that the true flow-through design simplifies board layout. Having the bus pins all on one side of the package for easy routing to a cable connector, and the Rx outputs and Tx inputs (logic pins) on the other side for easy connection to a UART, avoids costly and problematic crossovers. Competing "flow through" pinouts mix logic and bus pin inputs on one side of the package, and logic and bus pin outputs on the other side. This forces the designer to route four traces from the right side of the IC around the IC to the cable connector. Figure 11 illustrates the flow-through nature of the ISL333X's pinout.
ISL3332
Proper termination is imperative to minimize reflections when using the 20Mbps speed option. Short networks using the medium and slow speed options need not be terminated, but terminations are recommended unless power dissipation is an overriding concern. Note that the RS-485 spec allows a maximum of two terminations on a network, otherwise the Tx output voltage may not meet the required VOD. In point-to-point, or point-to-multipoint (RS-422) networks, the main cable should be terminated in its characteristic impedance (typically 120) at the end farthest from the driver. In multi-receiver applications, stubs connecting receivers to the main cable should be kept as short as possible, but definitely shorter than the limits shown in Table 4. Multipoint (RS-485) systems require that the main cable be terminated in its characteristic impedance at both ends. Again, keep stubs connecting a transceiver to the main cable as short as possible, and refer to Table 4. Avoid "star", and other configurations, where there are many "ends" which would require more than the two allowed terminations to prevent reflections.
A1 B1 CONNECTOR Y1 Z1 Z2 Y2 B2 A2
R
UART RA1
D
OR ASIC OR
DY1
DY2 RA2
CONTROLLER
FIGURE 11. ILLUSTRATION OF FLOW THROUGH PINOUT
Low Power Shutdown (SHDN) Mode
The ON/OFF pin is driven low to place the IC (both ports) in the SHDN mode, and the already low supply current drops to as low as 21A. If this functionality isn't desired, the pin can be left disconnected (thanks to the internal pull-up), or it should be connected to VCC (VL for the QFN), through a 1k resistor. SHDN disables the Tx and Rx outputs, and disables the charge pumps if either port is in RS-232 mode, so V+ collapses to VCC, and V- collapses to GND.
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ISL3332, ISL3333
All but 10uA of SHDN supply current (ICC plus IL) is due to control input (ON, LB, SP, DE, DEN) pull-up resistors (~11A/resistor), so SHDN supply current varies depending on the ISL333X configuration. The spec tables indicate the SHDN currents for configurations that optimize these currents. For example, in RS-232 mode the SP pins aren't used, so if both ports are configured for RS-232, floating or tying the SP pins high minimizes SHDN current. Likewise in RS-485 mode, the drivers are disabled in SHDN, so driving the DE and DEN pins high during this time also reduces the supply current. When enabling from SHDN in RS-232 mode, allow at least 25s for the charge pumps to stabilize before transmitting data. The charge pumps aren't used in RS-485 mode, so the transceiver is ready to send or receive data in less than 2s, which is much faster than competing devices that require the charge pump for all modes of operation.
VCC = +3.3V VCC = +2V
RA
VOH = 3.3V
RXD
ESD DIODE
DY GND
VIH 2 VOH 2
TXD GND
ISL3332 VCC = +3.3V
UART/PROCESSOR VCC = +2V
VL RA VOH = 2V RXD ESD DIODE
Internal Loopback Mode
Driving the LB pin low places both ports in the loopback mode, a mode that facilitates implementing board level self test functions. In loopback, internal switches disconnect the Rx inputs from the Rx outputs, and feed back the Tx outputs to the appropriate Rx output. This way the data driven at the Tx input appears at the corresponding Rx output (refer to "Typical Operating Circuits" on page 6"). The Tx outputs remain connected to their terminals, so the external loads are reflected in the loopback performance. This allows the loopback function to potentially detect some common bus faults such as one or both driver outputs shorted to GND, or outputs shorted together. Note that the loopback mode uses an additional set of receivers, as shown in the "Typical Operating Circuits". These loopback receivers are not standards compliant, so the loopback mode can't be used to implement a half-duplex RS-485 transceiver. If loopback won't be utilized, the pin can be left disconnected (thanks to the internal pull-up), or it should be connected to VCC (VL for the QFN), through a 1k resistor.
DY GND
VIH = 1V VOH 2
TXD GND
ISL3333
UART/PROCESSOR
FIGURE 12. USING VL PIN TO ADJUST LOGIC LEVELS
with the logic device output levels. Tailoring the logic pin input switching points and output levels to the supply voltage of the UART, ASIC, or controller eliminates the need for a level shifter/translator between the two ICs. VL can be anywhere from VCC down to 1.2V, but the input switching points may not provide enough noise margin when VL < 1.5V. Table 5 indicates typical VIH and VIL values for various VL voltages so the user can ascertain whether or not a particular VL voltage meets his needs.
TABLE 5. VIH AND VIL vs. VL FOR VCC = 3.3V VL (V) 1.2 1.5 1.8 2.3 2.7 3.3 VIH (V) 0.85 0.9 0.9 1.2 1.4 1.8 VIL (V) 0.26 0.5 0.73 1.0 1.3 1.7
ISL3333 (QFN Package) Special Features
Logic Supply (VL Pin)
The ISL3333 (QFN) includes a VL pin that powers the logic inputs (Tx inputs and control pins) and Rx outputs. These pins interface with "logic" devices such as UARTs, ASICs, and controllers, and today most of these devices use power supplies significantly lower than 3.3V. Thus, a 3.3V output level from a 3.3V powered dual protocol IC might seriously overdrive and damage the logic device input. Similarly, the logic device's low VOH might not exceed the VIH of a 3.3V powered dual protocol input. Connecting the VL pin to the power supply of the logic device (Figure 12) limits the ISL3333's Rx output VOH to VL (Figure 15), and reduces the Tx and control input switching points to values compatible 18
Note: With VL 1.6V, the ISL3333 may not operate at the full data rate unless the logic signal VIL is at least 0.2V below the typical value listed in Table 5. The VL supply current (IL) is typically less than 80A, even in the worst case configuration, as shown in Figures 20 and 21. With the Rx outputs unloaded, all of the DC VL current is due to inputs with internal pull-up resistors (DE, DEN, SP, LB,
FN6362.0 May 27, 2008
ISL3332, ISL3333
ON/OFF) being driven to the low input state. The worst case IL current occurs during SHDN (see Figure 21), due to the IL through the ON/OFF pin pull-up resistor when that pin is driven low. IIL through an input pull-up resistor is ~11A (6A for DE1 and DE2), so the IL in Figure 20 drops by about 22A (at VL = 3.3V) when the two SP inputs are high versus low (next to bottom vs. top curve). SHDN IL is lowest in the RS-232 mode, because only the DEN pins and/or the ON/OFF pin should be driven low. When all the inputs with pull-downs are driven high, IL drops to <<1A (see Figure 20), so to minimize power dissipation drive these inputs high when unneeded (e.g., SP inputs aren't used in RS-232 mode, and DEN inputs aren't used in RS-485 mode, so drive them high in those modes). QFN logic input pins that are externally tied high in an application, should use the VL supply for the high voltage level.
+3.3V ISL3330 VCC RA Tx/Rx RXEN DEN DY D R B A Y Z GND + 0.1F
ACTIVE HIGH RX ENABLE +3.3V ISL3333 VCC RA RXEN * R B A Y D Z GND * QFN ONLY ACTIVE LOW RX ENABLE + 0.1F
RS-232 Mode Tx Enable/Disable (DEN)
The ISL3333 also adds an RS-232 mode Tx enable pin (DENX) for each port. Driving one of these pins low disables both drivers in the corresponding port. Because RS-232 is a point-to-point (only one Tx allowed on the bus) standard, the main use for this disable function is to reduce power by eliminating the load current (approximately 1mA per Tx output) through the 5k resistor in the Rx at the cable's far end. The ICC in this mode is still considerably higher than in SHDN, but the enable time from Tx disable is much faster (1.5s vs. 25s) than the enable time from SHDN due to the charge pumps remaining on during Tx disable. The DENX pin is ignored if the corresponding port is set for RS-485 mode, and it is internally pulled high.
Tx/Rx DE DY
FIGURE 13. USING ACTIVE LOW vs ACTIVE HIGH RX ENABLE
Active Low Rx Enable (RXEN)
In many RS-485 applications, especially half duplex configurations, users like to accomplish "echo cancellation" by disabling the corresponding receiver while its driver is transmitting data. This function is available on the QFN package via an active low RXEN pin for each port. The active low function also simplifies direction control, by allowing a single Tx/Rx direction control line. If an active high RXEN were used, either two valuable I/O pins would be used for direction control, or an external inverter is required between DE and RXEN. Figure 13 details the advantage of using the RXEN pin.
minimize EMI and reflections. Nevertheless, for the best jitter performance when driving long cables, the faster speed options may be preferable, even at lower data rates. The faster output transitions deliver less variability (jitter) when loaded with the large capacitance associated with long cables. Of course, faster transitions require more attention to ensuring short stub lengths and quality terminations, so there are trade-offs to be made. Assuming a jitter budget of 10%, it is likely better to go with the slow speed option for data rates of 115kbps or less, to minimize fast edge effects. Likewise, the medium speed option is a good choice for data rates between 115kbps and 460kbps. For higher data rates, or when the absolute best jitter is required, use the high speed option. Speed selection is via the SPA and SPB pins (see Table 3), and the selection pertains to each port programmed for RS-485 mode.
Evaluation Board
An evaluation board, part number ISL3333EVAL1Z, is available to assist in assessing the dual protocol IC's performance. The evaluation board contains a QFN packaged device, but because the same die is used in all packages, the board is also useful for evaluating the functionality of the other versions. The board's design allows for evaluation of all standard features, plus the QFN specific features. Refer to the eval board application note for details, and contact your sales rep for ordering information.
RS-485 Slew Rate Limited Data Rates
The SSOP version of this IC operates with Tx output transitions optimized for a 20Mbps data rate. These fast edges may increase EMI and reflection issues, even though fast transitions aren't required at the lower data rates used by many applications. The ISL3333 (QFN version) solves this problem by offering two additional, slew rate limited, data rates that are optimized for speeds of 115kbps, and 460kbps.The slew limited edges permit longer unterminated networks, or longer stubs off terminated busses, and help 19
FN6362.0 May 27, 2008
ISL3332, ISL3333 Typical Performance Curves
30 RECEIVER OUTPUT CURRENT (mA) VOL, +25 C HIGH OUTPUT VOLTAGE (V) 25 20 15 10 5.0 0 VOH, +25 C VOL, +85 C
VCC = VL = 3.3V, TA = +25C; Unless Otherwise Specified
3.5 3.0 2.5 2.0 1.5 1.0 0.5 IOH = -2mA 0
VOH, +85 C
IOH = -0.5mA IOH = -1mA IOH = -6mA
0
1 2 RECEIVER OUTPUT VOLTAGE (V)
3
3.3
1
1.5
2.0 VL (V)
2.5
3.0
3.3
FIGURE 14. RECEIVER OUTPUT CURRENT vs RECEIVER OUTPUT VOLTAGE
90 DRIVER OUTPUT CURRENT (mA) 80 70 60 50 40 30 20 10 0 0 0.5 1 1.5 2 2.5 3 3.5 DIFFERENTIAL OUTPUT VOLTAGE (V)
FIGURE 15. RECEIVER HIGH OUTPUT VOLTAGE vs LOGIC SUPPLY VOLTAGE (VL) (QFN ONLY)
DIFFERENTIAL OUTPUT VOLTAGE (V) 2.30 2.25 2.20 2.15 2.10 2.05 2.00 1.95 1.9 -40 -25 0 50 25 TEMPERATURE (C) 75 85 RDIFF = 54 RDIFF = 100
FIGURE 16. RS-485, DRIVER OUTPUT CURRENT vs DIFFERENTIAL OUTPUT VOLTAGE
250 +85 C 200 150 OUTPUT CURRENT (mA) 100 -40 C +25 C
FIGURE 17. RS-485, DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs TEMPERATURE
4.5 RS-232, RXEN = X, DEN = VL (IF QFN) 4.0 3.5 RS-232, DEN = GND, RXEN = X (QFN ONLY) ICC (mA) 3.0 2.5 RS-485, HALF DUPLEX, DE = VCC, RXEN = X 2.0 1.5
50 Y OR Z = LOW 0 Y OR Z = HIGH -50 +85 C -40 C -7 -6 -4 -2 0 2 4 6 OUTPUT VOLTAGE (V) 8 10 12 +25 C
-100 -150
RS-485, DE = GND, RXEN = X -25 RS-485, FULL DUPLEX, DE = VCC, RXEN = X 0 50 25 75 TEMPERATURE (C) 85
1 -40
FIGURE 18. RS-485, DRIVER OUTPUT CURRENT vs SHORT CIRCUIT VOLTAGE
FIGURE 19. SUPPLY CURRENT vs TEMPERATURE
20
FN6362.0 May 27, 2008
ISL3332, ISL3333 Typical Performance Curves
60 NO LOAD VIN = VL or GND 50 LB = ON = VL, RXEN = GND VL VCC VL > VCC
VCC = VL = 3.3V, TA = +25C; Unless Otherwise Specified (Continued)
100 90 80 70 ICC and IL (A) NO LOAD VIN = VL or GND LB = VL ON = DZ/DE = DY = GND
D GN
40 IL (A)
E ,D ND =G N= VL
60 50 40 30 20 10
30
5 -48 RS E ,D P =S
20
RS-2
RS-485 ,D
32
GN N= , DE
P= D, S
VL
10
D, S P E = GN
= DE N
= VL
D P GN ,S N= 5 IL DE = -48 SP RS I, 32 L = VL -2 EN RS D, D GN = GN D , SP N= 85 I L , DE S-4 = VL R , SP 32 I L RS-2
= EN =D
= DEN RS-232 I L, SP
= VL
RS-232, DEN = SP = VL 0 1 1.5 2.0 2.5 VL (V) 3.0 3.5 4.0
RS-232/RS-485 ICC 1.5 2.0 2.5 VL (V) 3.0 3.5 4.0
0 1
FIGURE 20. VL SUPPLY CURRENT vs VL VOLTAGE (QFN ONLY)
1640 1630
FIGURE 21. VCC and VL SHDN SUPPLY CURRENTS vs VL VOLTAGE (QFN ONLY)
300
RDIFF = 54, CL = 100pF
RDIFF = 54, CL = 100pF |tPLHZ - tPHLY|
250 PROPAGATION DELAY (ns) 1620 1610 tDHL 1600 1590 1580 1570 1560 1550 -40 -25 0 25 50 75 85 0 -40 -25 0 tDHL tDLH SKEW (ns) 150 200 |tPHLZ - tPLHY|
100
50 |tDLH - tDHL| 25 50 75 85
TEMPERATURE (C)
TEMPERATURE (C)
FIGURE 22. RS-485, DRIVER PROPAGATION DELAY vs TEMPERATURE (SLOW DATA RATE, QFN ONLY)
550 545 PROPAGATION DELAY (ns) 540 535 530 525 520 515 -40 RDIFF = 54, CL = 100pF
FIGURE 23. RS-485, DRIVER SKEW vs TEMPERATURE (SLOW DATA RATE, QFN ONLY)
16 14 12 10 SKEW (ns) |tPLHZ - tPHLY| RDIFF = 54, CL = 100pF
tDHL tDLH tDHL
8 6 4
|tPHLZ - tPLHY|
|tDLH - tDHL| 2 0 -40 0 25 TEMPERATURE (C) 50 85
-25
0
25 TEMPERATURE (C)
50
75
85
-25
75
FIGURE 24. RS-485, DRIVER PROPAGATION DELAY vs TEMPERATURE (MEDIUM DATA RATE, QFN ONLY)
FIGURE 25. RS-485, DRIVER SKEW vs TEMPERATURE (MEDIUM DATA RATE, QFN ONLY)
21
FN6362.0 May 27, 2008
ISL3332, ISL3333 Typical Performance Curves
24 23
PROPAGATION DELAY (ns) 2.5 |tDLH - tDHL| RDIFF = 54, CL = 100pF
VCC = VL = 3.3V, TA = +25C; Unless Otherwise Specified (Continued)
3.0 RDIFF = 54, CL = 100pF
22 21 20
SKEW (ns) 1.5 tDLH 2.0
19
tDHL
|tPHLZ - tPLHY|
18 17
1.0
0.5
16 15
-40 -25 0 25 TEMPERATURE (C) 50 75 85 0 -40 -25
|tPLHZ - tPHLY| 0 25 TEMPERATURE (C) 50 75 85
FIGURE 26. RS-485, DRIVER PROPAGATION DELAY vs TEMPERATURE (FAST DATA RATE)
DRIVER INPUT (V) RECEIVER OUTPUT (V) RDIFF = 54, CL = 100pF DY 5 0
FIGURE 27. RS-485, DRIVER SKEW vs TEMPERATURE (FAST DATA RATE)
RECEIVER OUTPUT (V) RDIFF = 54, CL = 100pF DY 5 0 DRIVER INPUT (V) DRIVER INPUT (V)
5 0
5 0
RA
RA
DRIVER OUTPUT (V)
DRIVER OUTPUT (V)
4 Y 3 2 1 0 TIME (400ns/DIV) Z
4 Z 3 2 Y 1 0 TIME (400ns/DIV)
FIGURE 28. RS-485, DRIVER AND RECEIVER WAVEFORMS, LOW TO HIGH (SLOW DATA RATE, QFN ONLY)
DRIVER INPUT (V) RECEIVER OUTPUT (V) RDIFF = 54, CL = 100pF DY 5 0
FIGURE 29. RS-485, DRIVER AND RECEIVER WAVEFORMS, HIGH TO LOW (SLOW DATA RATE, QFN ONLY)
RECEIVER OUTPUT (V) RDIFF = 54, CL = 100pF DY 5 0
5 0
5 0
RA
RA
DRIVER OUTPUT (V)
DRIVER OUTPUT (V)
4 Y 3 2 1 0 TIME (200ns/DIV) Z
4 Z 3 2 Y 1 0 TIME (200ns/DIV)
FIGURE 30. RS-485, DRIVER AND RECEIVER WAVEFORMS, LOW TO HIGH (MEDIUM DATA RATE, QFN ONLY)
FIGURE 31. RS-485, DRIVER AND RECEIVER WAVEFORMS, HIGH TO LOW (MEDIUM DATA RATE, QFN ONLY)
22
FN6362.0 May 27, 2008
ISL3332, ISL3333 Typical Performance Curves
RECEIVER OUTPUT (V)
VCC = VL = 3.3V, TA = +25C; Unless Otherwise Specified (Continued)
DRIVER INPUT (V) RECEIVER OUTPUT (V) RDIFF = 54, CL = 100pF DY 5 0 DRIVER INPUT (V) 85
RDIFF = 54, CL = 100pF DY 5 0
5 0
5 0
RA
RA
DRIVER OUTPUT (V)
DRIVER OUTPUT (V)
4 Y 3 2 1 0 TIME (10ns/DIV) Z
4 3 2 1 0
Z
Y
TIME (10ns/DIV)
FIGURE 32. RS-485, DRIVER AND RECEIVER WAVEFORMS, LOW TO HIGH (FAST DATA RATE)
7.5 TRANSMITTER OUTPUT VOLTAGE (V) RS-232 REGION OF NONCOMPLIANCE
FIGURE 33. RS-485, DRIVER AND RECEIVER WAVEFORMS, HIGH TO LOW (FAST DATA RATE)
7.5 TRANSMITTER OUTPUT VOLTAGE (V)
5.0 2.5
VOUT+
250kbps
5.0
VOUT+
2.5 OUTPUTS STATIC ALL TOUTS LOADED WITH 3k TO GND AND AT V+ OR V-
ALL TOUTS LOADED WITH 3k TO GND 0 -2.5 -5 VOUT -7.5 0 1000 2000 3000 2 TRANSMITTERS AT 250kbps or 400kbps, OTHER TRANSMITTERS AT 30kbps
400kbps
0
400kbps 250kbps 4000 5000
-2.5
-5 VOUT -7.5 -40 -25 0 25 TEMPERATURE (C) 50 75
LOAD CAPACITANCE (pF)
FIGURE 34. RS-232, TRANSMITTER OUTPUT VOLTAGE vs LOAD CAPACITANCE
50 TRANSMITTER OUTPUT CURRENT (mA) 40 30 20 VOUT SHORTED TO GND 10 0 -10 Y or Z = HIGH -20 -30 -40 -25 0 25 50 75 85
FIGURE 35. RS-232, TRANSMITTER OUTPUT VOLTAGE vs TEMPERATURE
CL = 2000pF, 2 CHANNELS SWITCHING Y or Z = LOW 5 DY 0 5 0 Y/A -5 5 RA 0
2s/DIV.
TEMPERATURE (C)
FIGURE 36. RS-232, TRANSMITTER SHORT CIRCUIT CURRENT vs TEMPERATURE
FIGURE 37. RS-232, TRANSMITTER AND RECEIVER WAVEFORMS AT 250kbps
23
FN6362.0 May 27, 2008
ISL3332, ISL3333 Typical Performance Curves
5 DY 0 5 0 Y/A -5 5 RA 0
VCC = VL = 3.3V, TA = +25C; Unless Otherwise Specified (Continued)
58
CL = 1000pF, 2 CHANNELS SWITCHING RECEIVER + DUTY CYCLE (%)
VIN = 5V FULL TEMP RANGE
57 56 55
SR IN = 15V/s
54 53 52 51 50 49 0 500 1000 1500 2000
SR IN = 100V/s
2s/DIV.
DATA RATE (kbps)
FIGURE 38. RS-232, TRANSMITTER AND RECEIVER WAVEFORMS AT 400kbps
550 500 450 DATA RATE (kbps) 400 350 300 250 200 2 TRANSMITTERS AT +85C 150 100 0 1000 2000 3000 4000 LOAD CAPACITANCE (pF) 5000 1 TRANSMITTER AT +85C 2 TRANSMITTERS AT +25C 1 TRANSMITTER AT +25C VOUT 4V AND DUTY CYCLE BETWEEN 40% AND 60% ALL TOUTS LOADED WITH 5k TO GND
FIGURE 39. RS-232, RECEIVER OUTPUT +DUTY CYCLE vs DATA RATE
7.5 TRANSMITTER OUTPUT VOLTAGE (V) +25C +85C RS-232 REGION OF NONCOMPLIANCE
5 2.5
VOUT+
2 TRANSMITTERS SWITCHING 0 ALL TOUTS LOADED WITH 5k TO GND, CL = 1000pF -2.5 +85C VOUT -7.5 0 100 200 300 400 DATA RATE (kbps) 500 600 +25C
-5
FIGURE 40. RS-232, TRANSMITTER MAXIMUM DATA RATE vs LOAD CAPACITANCE
650 2 TRANSMITTERS SWITCHING
FIGURE 41. RS-232, TRANSMITTER OUTPUT VOLTAGE vs DATA RATE
Die Characteristics
SUBSTRATE AND QFN PAD POTENTIAL (POWERED UP): GND TRANSISTOR COUNT:
600 ALL TOUTS LOADED WITH 3k TO GND, CL = 1000pF 550 SKEW (ns) 500 450 400 +25C 350 300 250 0 50 200 400 DATA RATE (kbps) -40 C +85C
4838 PROCESS: BiCMOS
600 650
FIGURE 42. RS-232, TRANSMITTER SKEW vs DATA RATE
24
FN6362.0 May 27, 2008
ISL3332, ISL3333 Shrink Small Outline Plastic Packages (SSOP)
N INDEX AREA E -B1 2 3 L SEATING PLANE -AD -CA 0.25 0.010 GAUGE PLANE H 0.25(0.010) M BM
M28.209 (JEDEC MO-150-AH ISSUE B)
28 LEAD SHRINK SMALL OUTLINE PLASTIC PACKAGE INCHES SYMBOL A A1 A2 B C D MIN 0.002 0.065 0.009 0.004 0.390 0.197 MAX 0.078 0.072 0.014 0.009 0.413 0.220 MILLIMETERS MIN 0.05 1.65 0.22 0.09 9.90 5.00 MAX 2.00 1.85 0.38 0.25 10.50 5.60 NOTES 9 3 4 6 7 8 Rev. 2 6/05
A1 0.10(0.004) A2 C
E e H L N
e
B 0.25(0.010) M C AM BS
0.026 BSC 0.292 0.022 28 0 8 0.322 0.037
0.65 BSC 7.40 0.55 28 0 8.20 0.95
NOTES: 1. Symbols are defined in the "MO Series Symbol List" in Section 2.2 of Publication Number 95. 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. 3. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion and gate burrs shall not exceed 0.20mm (0.0078 inch) per side. 4. Dimension "E" does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.20mm (0.0078 inch) per side. 5. The chamfer on the body is optional. If it is not present, a visual index feature must be located within the crosshatched area. 6. "L" is the length of terminal for soldering to a substrate. 7. "N" is the number of terminal positions. 8. Terminal numbers are shown for reference only. 9. Dimension "B" does not include dambar protrusion. Allowable dambar protrusion shall be 0.13mm (0.005 inch) total in excess of "B" dimension at maximum material condition. 10. Controlling dimension: MILLIMETER. Converted inch dimensions are not necessarily exact.
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation's quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com 25
FN6362.0 May 27, 2008
ISL3332, ISL3333
Package Outline Drawing
L40.6x6
40 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE Rev 3, 10/06
4X 4.5 6.00 A B 6 PIN 1 INDEX AREA 31 30 36X 0.50 40 1 6 PIN #1 INDEX AREA
4 . 10 0 . 15 6.00
21 (4X) 0.15 20 TOP VIEW 40X 0 . 4 0 . 1 BOTTOM VIEW 11
10
0.10 M C A B 4 0 . 23 +0 . 07 / -0 . 05
SEE DETAIL "X" 0.10 C BASE PLANE SIDE VIEW ( 36X 0 . 5 ) SEATING PLANE 0.08 C C
0 . 90 0 . 1 ( 5 . 8 TYP ) ( 4 . 10 )
C ( 40X 0 . 23 ) ( 40X 0 . 6 ) TYPICAL RECOMMENDED LAND PATTERN
0 . 2 REF
5
0 . 00 MIN. 0 . 05 MAX. DETAIL "X"
NOTES: 1. Dimensions are in millimeters. Dimensions in ( ) for Reference Only. 2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994. 3. Unless otherwise specified, tolerance : Decimal 0.05 4. Dimension b applies to the metallized terminal and is measured between 0.15mm and 0.30mm from the terminal tip. 5. Tiebar shown (if present) is a non-functional feature. 6. The configuration of the pin #1 identifier is optional, but must be located within the zone indicated. The pin #1 identifier may be either a mold or mark feature.
26
FN6362.0 May 27, 2008

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