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19-3580; Rev 0; 2/05
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
General Description
The MAX3160E/MAX3161E/MAX3162E are programmable RS-232/RS-485/RS-422 multiprotocol transceivers. The MAX3160E/MAX3161E are pin programmable as a 2Tx/2Rx RS-232 interface or a single RS-485/RS-422 transceiver. The MAX3162E is configured as a 2Tx/2Rx RS-232 interface, and a single RS-485/RS-422 transceiver simultaneously. The MAX3160E/MAX3161E/MAX3162E feature enhanced electrostatic discharge (ESD) protection. All of the transmitter outputs and receiver inputs are protected to 15kV using the Human Body Model. All devices incorporate a proprietary low-dropout transmitter output stage, and an on-board dual charge pump to allow RS-232- and RS-485-/RS-422-compliant performance from a +3V to +5.5V supply. The receivers feature true fail-safe circuitry that guarantees a logic-high receiver output when the receiver inputs are open or shorted. These devices also feature pin-selectable transmitter slew rates for RS-232 and RS-485/RS-422 modes. Slewrate limiting minimizes EMI and reduces reflections caused by improperly terminated cables, allowing errorfree data transmission up to 250kbps. Disabling slew-rate limiting allows these devices to transmit at data rates up to 10Mbps in RS-485/RS-422 mode and up to 1Mbps in RS-232 mode. The MAX3160E/MAX3161E/MAX3162E feature a 10nA shutdown mode, short-circuit limiting, and thermal shutdown circuitry to protect against excessive power dissipation. The MAX3160E/MAX3162E offer a flow-through pinout that facilitates board layout. The MAX3160E/ MAX3161E/MAX3162E are available in tiny SSOP packages and operate over the commercial and extended temperature ranges.
Features
Single Supply Operation from +3V to +5.5V ESD Protection 15kV Human Body Model Pin-Selectable as 2Tx/2Rx RS-232 or Single RS-485/RS-422 (MAX3160E/MAX3161E) 2Tx/2Rx RS-232 and Single RS-485/RS-422 (MAX3162E) Pin-Selectable RS-232/RS-485 Transmitter Slew Rates Reduce EMI 10Mbps RS-485 and 1Mbps RS-232 Data Rates Pin-Selectable Half-Duplex or Full-Duplex RS-485/RS-422 Operation (MAX3160E/MAX3161E) RS-485/RS-422 True Fail-Safe Receivers 10nA Shutdown Supply Current 1/8-Unit Load Allows up to 256 Transceivers on the Bus
MAX3160E/MAX3161E/MAX3162E
Ordering Information
PART MAX3160ECAP MAX3160EEAP MAX3161ECAG MAX3161EEAG MAX3162ECAI MAX3162EEAI TEMP RANGE 0C to +70C -40C to +85C 0C to +70C -40C to +85C 0C to +70C -40C to +85C PINPACKAGE 20 SSOP 20 SSOP 24 SSOP 24 SSOP 28 SSOP 28 SSOP PACKAGE CODE A20-2 A20-2 A24-3 A24-3 A28-1 A28-1
Typical Operating Circuit
+3V TO +5.5V
________________________Applications
Point-of-Sales Equipment Industrial Controls RS-232 to RS-485 Interface Converters Peripherals Networking Security Systems
TX RTS 13 DI/T1IN 16 15 8 7
2 VCC RS-485/RS232 11
MAX3160E
Z(B)/T1OUT 5 6 13 14 RJ45 DB9
MAX3100 11
RX CTS 10 SPI 12
DE485/T2IN Y(A)/T2OUT RO/R2OUT R1OUT A/R2IN B/R1IN
GND FAST HDPLX SHDN 4 10 12 9
P
SHDN
Pin Configurations appear at end of data sheet. Selector Guide appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products 1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
ABSOLUTE MAXIMUM RATINGS
VCC to GND. .............................................................-0.3V to +6V V+ to GND ................................................................-0.3V to +7V V- to GND. ................................................................-7V to +0.3V V+ - V- (Note 1)....................................................................+13V Input Voltages T1IN, T2IN, DI, DE485, RE485, TE232, RE232, SHDN, FAST, HDPLX, RS485/RS232 to GND. .................-0.3V to +6V A, B, R1IN, R2IN to GND .................................................25V Output Voltages T1OUT, T2OUT, Y, Z to GND (VCC = 0 or SHDN = GND) ..............................................................13.2V T1OUT, T2OUT to GND (VCC = 5.5V and SHDN = VCC) .....................................................-13.2V to +9V R2OUT, R1OUT, RO to GND..................-0.3V to (VCC + 0.3V) Output Short-Circuit Duration T1OUT, T2OUT, Y, Z ..............................................Continuous Continuous Power Dissipation (TA = +70C) 20-Pin SSOP (derate 8.0mW/C above +70C) ...........640mW 24-Pin SSOP (derate 8.0mW/C above +70C) ...........640mW 28-Pin SSOP (derate 9.1mW/C above +70C) ...........727mW Operating Temperature Ranges MAX316_CA_ ......................................................0C to +70C MAX316_EA_ ...................................................-40C to +85C Storage Temperature Range .............................-65C to +150C Junction Temperature ......................................................+150C Lead Temperature (soldering, 10s) .................................+300C
Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = +3V to +5.5V, C1-C4 = 0.1F when tested at +3.3V 10%; C1 = 0.047F and C2, C3, C4 = 0.33F when tested at +5V10%; TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25C.) (Note 2)
PARAMETER DC CHARACTERISTICS SYMBOL CONDITIONS MAX3160E/MAX3161E, no load, RS-485/ RS-232 = GND VCC Standby Current ICC MAX3160E/MAX3161E, no load, RS-485/ RS-232 = VCC MAX3162E, no load VCC Shutdown Current ISHDN SHDN = GND, receiver inputs open or grounded MIN TYP MAX UNITS
1.2 2.5 3 0.01
2.8 5.5 6 1 A mA
TRANSMITTER AND LOGIC INPUTS (DI, T1IN, T2IN, DE485, RE 4 85 , TE232, R E 2 3 2 , FAST, HDPLX, SHDN, RS-485/ R S - 232 ) Logic-Input Low Logic-Input High Logic-Input Leakage Current Transmitter Logic Hysteresis Receiver Output-Voltage Low Receiver Output-Voltage High Receiver Output Short-Circuit Current Receiver Output Leakage Current VIL VIH IINL VHYS VOL VOH IOSR IOZR IOUT = 2.5mA IOUT = -1.5mA 0 VO VCC Receivers disabled VCC - 0.6 20 0.05 85 1 VCC = +3.3V VCC = +5V 2.0 2.4 0.01 0.5 0.4 1 0.8 V V A V V V mA A
RS-232 AND RS-485/RS-422 RECEIVER OUTPUTS (R1OUT, R2OUT, RO)
2
_______________________________________________________________________________________
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3V to +5.5V, C1-C4 = 0.1F when tested at +3.3V 10%; C1 = 0.047F and C2, C3, C4 = 0.33F when tested at +5V10%; TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25C.) (Note 2)
PARAMETER SYMBOL RS-232 RECEIVER INPUTS (R1IN, R2IN) Input Voltage Range Logic-Input Low Logic-input High Input Hysteresis Input Resistance RS-485/RS-422 RECEIVER INPUTS (Note 3) MAX3160E Input Resistance RIN -7V < VCM < +12V MAX3161E/ MAX3162E VCM = +12V VCM = -7V VCM = +12V VCM = -7V -200 30 Both transmitter outputs loaded with 3k to GND VCC = V+ = V- = 0, T_OUT = 2V ISC IO T_OUT = GND VOUT = 9V TE232 = GND or SHDN = GND MAX3160E MAX3161E MAX3162E R = 27 (RS-485) Differential Output Voltage VOD Figure 1 R = 50 (RS-422) R = 27 or 50, Figure 1 R = 27 or 50, Figure 1 2 48 96 0.25 -0.15 0.125 -0.075 -50 mV mV mA k VCC = +3.0V to 5.5V VCC = 0 3 6 VCC = +3.3V VCC = +5V 2.0 2.4 0.5 5 11 7 16 CONDITIONS MIN -25 TYP MAX +25 0.8 V V k UNITS V
MAX3160E/MAX3161E/MAX3162E
MAX3160E Input Current IIN MAX3161E/MAX3162E Input Differential Threshold Input Hysteresis VTH VTH -7V VCM +12V
RS-232 TRANSMITTER OUTPUTS (T1OUT, T2OUT) Output Voltage Swing Output Resistance Output Short-Circuit Current Output Leakage Current 5 300 5.4 10M 30 60 125 25 25 A V mA
RS-485/RS-422 TRANSMITTER OUTPUTS (Y, Z) 1.5 V
Change in Magnitude of Differential Output Voltage for Complementary Output States Common-Mode Output Voltage Change in Magnitude of Common-Mode Output Voltage for Complementary Output States
|VOD| VOC
0.2 3
V V
|VOC|
R = 27 or 50, Figure 1
0.2
V
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3
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3V to +5.5V, C1-C4 = 0.1F when tested at +3.3V 10%; C1 = 0.047F and C2, C3, C4 = 0.33F when tested at +5V10%; TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25C.) (Note 2)
PARAMETER Output Short-Circuit Current Output Leakage Current SYMBOL ISC IO CONDITIONS VY or VZ = -7V to +12V VY or VZ = -7V or +12V, DE485 = GND or SHDN = GND MAX3160E MAX3161E MAX3162E 250 25 6 4 30 V/s CL = 150pF to 2500pF 30 CL = 150pF to 1000pF MIN TYP MAX 250 125 25 25 kbps ns A UNITS mA
RS-232 TRANSMITTER TIMING CHARACTERISTICS (SLOW MODE, FAST = GND, 250kbps, one transmitter switching) Maximum Data Rate Transmitter Skew tTSKEW RL = 3k, CL = 1000pF RL = 3k, CL = 150pF, Figure 6 VCC = +3.3V, TA = +25C, RL = 3k to 7k, measured from +3.0V to -3.0V or -3.0V to +3.0V
Transition-Region Slew Rate
RS-232 TRANSMITTER TIMING CHARACTERISTICS (FAST MODE, FAST = VCC, 1Mbps, one transmitter switching) VCC = +3V to +4.5V, RL = 3k, CL = 250pF Maximum Data Rate Transmitter Skew tTSKEW VCC = +4.5V to +5.5V, RL = 3k, CL = 1000pF RL = 3k, CL = 150pF, Figure 6 VCC = +3.3V, TA = +25C, RL = 3k to 7k, CL = 150pF to 1000pF, measured from +3.0V to -3.0V or -3.0V to +3.0V tPHL,tPLH tRZL,tRZH tRLZ,tRHZ tRSKEW tDPHL, tDPLH tDR, tDF tDSKEW tDZH, tDZL tDLZ, tDHZ MAX3160E MAX3161E MAX3162E 13 24 1 1 10 150 V/s 150 Mbps ns
Transition-Region Slew Rate
RS-232 RECEIVER TIMING CHARACTERISTICS Receiver Propagation Delay Receiver Output Enable Time Receiver Output Disable Time Receiver Skew Differential Driver Propagation Delay Differential Driver Rise and Fall Time Differential Driver Propagation Delay Skew Driver Output Enable Time Driver Output Disable Time R_IN to R_OUT, CL = 15pF, Figure 5 CL = 50pF, Figures 2, 10, MAX3162E CL = 15pF, Figures 2, 10, MAX3162E CL = 50pF, Figure 5 0.15 200 200 100 s ns ns ns
RS-485/RS-422 DRIVER TIMING CHARACTERISTICS (SLOW MODE, FAST = GND, 250kbps) RDIFF = 54, CL = 50pF, Figures 3, 7 RDIFF = 54, CL = 50pF, Figures 3, 7 RDIFF = 54, CL = 50pF, Figures 3, 7 CL = 50pF, Figures 4, 8 CL = 50pF, Figures 4, 8 400 200 200 200 400 400 800 800 200 900 400 ns ns ns ns ns
4
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3V to +5.5V, C1-C4 = 0.1F when tested at +3.3V 10%; C1 = 0.047F and C2, C3, C4 = 0.33F when tested at +5V10%; TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25C.) (Note 2)
PARAMETER SYMBOL CONDITIONS RS-485/RS-422 DRIVER TIMING CHARACTERISTICS FAST MODE, FAST = VCC, 10Mbps) Differential Driver Propagation Delay Differential Driver Rise and Fall Times Differential Driver Propagation Delay Skew Driver Output Enable Time Driver Output Disable Time tDPHL, tDPLH tDR, tDF tDSKEW tDZH,tDZL tDHZ,tDLZ tRPLH, tRPHL tRSKEW tRZL, tRZH tRLZ, tRHZ RDIFF = 54, CL = 50pF, Figures 3, 7 RDIFF = 54, CL = 50pF, Figures 3, 7 RDIFF = 54, CL = 50pF, Figures 3, 7 CL = 50pF, Figures 4, 8 CL = 50pF, Figures 4, 8 400 200 MIN TYP MAX UNITS
MAX3160E/MAX3161E/MAX3162E
60 10
120 25 10 900 400
ns ns ns ns ns
RS-485/RS-422 RECEIVER TIMING CHARACTERISTICS Receiver Propagation Delay Receiver Propagation Delay Skew Receiver Output Enable Time Receiver Output Disable Time ESD PROTECTION R_IN, T_OUT, A, B, Y, Z Human Body Model 15 kV CL = 15pF, Figures 9, 11 CL = 15pF, Figures 9, 11 MAX3162E, CL = 50pF, Figures 2, 10 MAX3162E, CL = 15pF, Figures 2, 10 80 1 100 100 150 10 ns ns ns ns
Note 2: All currents into the device are positive. All currents out of the device are negative. Note 3: Applies to A, B for MAX3162E and MAX3160E/MAX3161E with HDPLX = GND, or Y, Z for MAX3160E/MAX3161E with HDPLX = VCC.
Typical Operating Characteristics
(VCC = +3.3V, 250kbps data rate, CBYPASS, C1, C2, C3, C4 = 0.1F, all RS-232 transmitters (RS-232 mode) loaded with 3k to ground, TA = +25C, unless otherwise noted.)
RS-232 TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE (FAST = GND)
MAX3160E toc01
RS-232 TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE (FAST = VCC)
DATA RATE = 1Mbps TRANSMITTER OUTPUT VOLTAGE (V) 7.50 5.00 SLEW RATE (V/s) 2.50 0 -2.50 -5.00 -7.50 0 500 1000 1500 2000 2500
MAX3160E toc02
RS-232 TRANSMITTER SLEW RATE vs. LOAD CAPACITANCE (FAST = GND)
16 14 12 FALLING 10 8 6 4 2 0 0 1000 2000 3000 4000 5000 RISING
MAX3160E toc03
10.00 TRANSMITTER OUTPUT VOLTAGE (V) 7.50 5.00 2.50 0 -2.50 -5.00 -7.50 0 1000 2000 3000 4000
10.00
18
-10.00 5000 LOAD CAPACITANCE (pF)
-10.00 LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
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5
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
Typical Operating Characteristics (continued)
(VCC = +3.3V, 250kbps data rate, CBYPASS, C1, C2, C3, C4 = 0.1F, all RS-232 transmitters (RS-232 mode) loaded with 3k to ground, TA = +25C, unless otherwise noted.) MAX3160E/MAX3161E OPERATING SUPPLY CURRENT RS-232 TRANSMITTER SLEW RATE NO-LOAD SUPPLY CURRENT vs. LOAD CAPACITANCE WHEN vs. LOAD CAPACITANCE (FAST = VCC) vs. TEMPERATURE TRANSMITTING DATA (RS-232 MODE)
MAX3160E toc04
100 90 SLEW RATE (V/s) 80 70 60 50 40 30 20 10 0 0 400 800 1200 1600 FALLING RISING
50 SUPPLY CURRENT (mA) 40
DATA RATE = 1Mbps
2.5 SUPPLY CURRENT (mA) 2.0 1.5 1.0 0.5 0
RS-485 MODE
DATA RATE = 250kbps 30 20 DATA RATE = 20kbps 10 0
RS-232 MODE
2000
0
1000
2000
3000
4000
5000
-40
-15
10
35
60
85
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
TEMPERATURE (C)
SHUTDOWN CURRENT vs. TEMPERATURE
MAX3160E toc07
RS-485/RS-422 OUTPUT CURRENT vs. DRIVER-OUTPUT LOW VOLTAGE
MAX3160E toc08
RS-485/RS-422 OUTPUT CURRENT vs. DRIVER-OUTPUT LOW VOLTAGE
MAX3160E toc09
250
140 120 OUTPUT CURRENT (mA) 100 80 60 40 20
140 120 OUTPUT CURRENT (mA) 100 80 60 40 20 0
SHUTDOWN CURRENT (nA)
200
150
100
50
0 -40 -15 10 35 60 85 TEMPERATURE (C)
0 0 2 4 6 8 10 12 OUTPUT LOW VOLTAGE (V)
-7
-5
-3
-1
1
3
5
OUTPUT LOW VOLTAGE (V)
RS-485/RS-422 DRIVER OUTPUT CURRENT vs. DIFFERENTIAL OUTPUT VOLTAGE
MAX3160E toc10
RS-485/RS-422 DRIVER DIFFERENTIAL OUTPUT vs. TEMPERATURE
2.9 2.8 OUTPUT VOLTAGE (V) 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2.0 RDIFF = 100 FIGURE 1
MAX3160E toc11
RECEIVER OUTPUT CURRENT vs. RECEIVEROUTPUT LOW VOLTAGE
MAX3160E toc12
100 90 80 OUTPUT CURRENT (mA) 70 60 50 40 30 20 10 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
3.0
30 25 OUTPUT CURRENT (mA) 20 15 10 5 0
4.0
-40
-15
10
35
60
85
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
OUTPUT LOW VOLTAGE (V)
TEMPERATURE (C)
OUTPUT LOW VOLTAGE (V)
6
_______________________________________________________________________________________
MAX3160E toc06
MAX3160E to05
110
60
3.0
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
Typical Operating Characteristics (continued)
(VCC = +3.3V, 250kbps data rate, CBYPASS, C1, C2, C3, C4 = 0.1F, all RS-232 transmitters (RS-232 mode) loaded with 3k to ground, TA = +25C, unless otherwise noted.)
RECEIVER OUTPUT CURRENT vs. RECEIVER-OUTPUT HIGH VOLTAGE
MAX3160E toc13
RS-485/RS-422 RECEIVER PROPAGATION DELAY vs. TEMPERATURE
MAX3160E toc14
RS-485/RS-422 DRIVER PROPAGATION DELAY vs. TEMPERATURE (FAST = VCC)
CL = 50pF RDIFF = 54 DATA RATE = 10Mbps RISING FALLING
MAX3160E toc15
14 12 OUTPUT CURRENT (mA) 10 8 6 4 2 0 0 0.5 1.0 1.5 2.0 2.5 3.0
100 90 PROPAGATION DELAY (ns) 80 70 60 50 40 30 20 10 0 FALLING RISING
50 45 PROPAGATION DELAY (ns) 40 35 30 25 20
3.5
-40
-15
10
35
60
85
-40
-15
10
35
60
85
OUTPUT-HIGH VOLTAGE (V)
TEMPERATURE (C)
TEMPERATURE (C)
RS-485/RS-422 DRIVER PROPAGATION DELAY vs. TEMPERATURE (FAST = GND)
MAX3160E toc16
RS-485/RS-422 DRIVER PROPAGATION (FAST = VCC, 10Mbps)
CL = 50pF RDIFF = 54
RS-485/RS-422 DRIVER PROPAGATION (FAST = GND, 250kbps)
MAX3160E toc18
MAX3160E toc17
400 350 PROPAGATION DELAY (ns) 300 FALLING 250 200 150 100 -40 -15 10 35 60 CL = 50pF RDIFF = 54 DATA RATE = 250kbps RISING
DI 2V/div
CL = 50pF RDIFF = 54
DI 2V/div
VY - V Z 2V/div
VY - V Z 2V/div
85
20ns/div
1.0s/div
TEMPERATURE (C)
I-V OUTPUT IMPEDANCE CURVE IN RS-232 SHUTDOWN MODE
MAX3160E toc19
RS-485/RS-422 RECEIVER PROPAGATION (FAST = VCC, 5Mbps)
MAX3160E toc20
RS-485/RS-422 RECEIVER PROPAGATION (FAST = VCC, 5Mbps)
MAX3160E toc21
400 200 OUTPUT CURRENT (A) 0 -200 -400 -600 -800 -1000 -20 -15 -10 -5 0 5 10 15
CL = 15pF VY - V Z 2V/div
CL = 50pF RDIFF = 54 DE485 2V/div
RO 2V/div
VY - V Z 2V/div
20
4ns/div
100ns/div
OUTPUT VOLTAGE (V)
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7
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
Typical Operating Characteristics (continued)
(VCC = +3.3V, 250kbps data rate, CBYPASS, C1, C2, C3, C4 = 0.1F, all RS-232 transmitters (RS-232 mode) loaded with 3k to ground, TA = +25C, unless otherwise noted.)
MAX3160E RS-232 TRANSMITTER PROPAGATION (FAST = GND, 250kbps)
MAX3160E toc22
MAX3160E RS-232 TRANSMITTER PROPAGATION (FAST = VCC, 250kbps)
CL = 150pF RL = 7k DI 2V/div
MAX3160E toc23
CL = 1000pF RL = 7k
DI 2V/div
T_OUT 5V/div
T_OUT 5V/div
1.0s/div
1.0s/div
MAX3161E/MAX3162E RS-232 TRANSMITTER PROPAGATION (FAST = GND, 250kbps)
MAX3160E toc24
MAX3161E/MAX3162E RS-232 TRANSMITTER PROPAGATION (FAST = VCC, 250kbps)
CL = 150pF RL = 7k DI 2V/div
MAX3160E toc25
CL = 1000pF RL = 7k
DI 2V/div
T_OUT 5V/div
T_OUT 5V/div
1.0s/div
1.0s/div
TRANSMITTER OUTPUT VOLTAGE vs. SUPPLY VOLTAGE (FAST = GND)
MAX3160E toc26
SUPPLY CURRENT vs. SUPPLY VOLTAGE WITH RS-232 RUNNING (FAST = GND)
MAX3160E toc27
10.00 TRANSMITTER OUTPUT VOLTAGE (V) 7.50 5.00 2.50 0 -2.50 -5.00 -7.50 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 INPUTS AT VCC AND GND 2 TRANSMITTERS LOADED WITH 3k
12 10 SUPPLY CURRENT (mA) 8 6 4 2 0 CL = 50pF RL = 3k 1 TRANSMITTER AT 250kbps 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
-10.00 6.0 SUPPLY VOLTAGE (V)
6.0
SUPPLY VOLTAGE (V)
8
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
Pin Description
PIN MAX3160E 1 2 3 4 -- 5 -- -- MAX3161E 1 2 3 4 5 -- -- 6 MAX3162E 1 2 3 4 5 -- 6 -- NAME C1+ VCC C1GND T1OUT Z(B)/T1OUT Z Z(B) FUNCTION Positive Terminal of the Positive Flying Capacitor Positive Supply Voltage Negative Terminal of the Positive Flying Capacitor Ground RS-232 Driver Output Inverting RS-485/RS-422 Driver Output in Full-Duplex Mode (and Inverting RS-485/RS-422 Receiver Input in Half-Duplex Mode)/RS-232 Driver Output Inverting RS-485/RS-422 Driver Output Inverting RS-485/RS-422 Driver Output in Full-Duplex Mode (and Inverting RS-485/RS-422 Receiver Input in Half-Duplex Mode) Noninverting RS-485/RS-422 Driver Output in Full-Duplex Mode (and Noninverting RS-485/RS-422 Receiver Input in Half-Duplex Mode)/RS-232 Driver Output Noninverting RS-485/RS-422 Driver Output Noninverting RS-485/RS-422 Driver Output in Full-Duplex Mode (and Noninverting RS-485/RS-422 Receiver Input in Half-Duplex Mode) RS-232 Receiver Output RS-232 Driver Output RS-485/RS-422 Receiver Output/RS-232 Receiver Output Active-Low Shutdown-Control Input. Drive SHDN low to shut down transmitters and charge pump. RS-232 Driver Output Transmitter Speed-Select Input. Select slew-rate limiting for RS-232 and RS-485/RS-422. Slew-rate limits with a logic-level low. RS-485/RS-422 Receiver Output Pin-Selectable Mode Functionality Input. Operates as RS-485/RS-422 with a logic-level high; operates as RS-232 with a logic-level low. RS-485/RS-422 Receiver Enable Input. Logic-level low enables RS-485/RS-422 receivers. Pin-Selectable Mode Functionality Input. Operates in fullduplex mode when low; operates in half-duplex mode when high.
MAX3160E/MAX3161E/MAX3162E
6 -- -- 7 -- 8 9 -- 10 -- 11
-- -- 7 9 8 10 11 -- 12 -- 13
-- 7 -- 9 8 -- 13 10 14 11 --
Y(A)/T2OUT Y Y(A) R1OUT T2OUT RO/R2OUT SHDN R2OUT FAST RO RS-485/RS-232
--
--
12
RE485
12
14
--
HDPLX
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9
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
Pin Description (continued)
PIN MAX3160E 13 14 -- -- 15 -- -- 16 -- 17 -- 18 19 20 -- -- -- -- MAX3161E -- -- -- 15 19 -- 16 20 17 21 18 22 23 24 -- -- -- -- MAX3162E -- -- 15 17 -- 16 18 -- 19 25 20 26 27 28 21 22 23 24 NAME A/R2IN B/R1IN RE232 A DE485/T2IN TE232 B DI/T1IN R2IN VR1IN C2C2+ V+ T2IN DE485 DI T1IN FUNCTION Noninverting RS-485/RS-422 Receiver Input/RS-232 Receiver Input Inverting RS-485/RS-422 Receiver Input/RS-232 Receiver Input RS-232 Receiver Enable. Logic-level low enables RS-232 receivers. Noninverting RS-485/RS-422 Receiver Input RS-485/RS-422 Driver Enable/RS-232 Driver Input RS-232 Transmitter Output Enable Inverting RS-485/RS-422 Receiver Input RS-485/RS-422 Driver Input/RS-232 Driver Input RS-232 Receiver Input Negative Charge-Pump Rail RS-232 Receiver Input Negative Terminal of the Negative Flying Capacitor Positive Terminal of the Negative Flying Capacitor Positive Charge-Pump Rail RS-232 Driver Input RS-485/RS-422 Driver Enable Input RS-485/RS-422 Driver Input RS-232 Driver Input
10
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
MAX3160E Functional Diagram
MAX3160E/MAX3161E/MAX3162E
RS-232 MODE VCC 1 C1 2 3 CBYPASS 4 5 6 7 8 9 SHDN MAX3160E 10 FAST RS-485/RS-232 11 10 FAST GND ESD PROTECTION T1 T2 ESD PROTECTION R1 R2 V17 C4 RS-232 OUTPUTS 16 15 14 13 RS-232 INPUTS LOGIC INPUTS 5 RS-485 OUTPUTS 6 7 R0 LOGIC OUTPUT 8 9 SHDN R C1+ VCC C1CHARGE PUMP V+ C2+ C220 C3 19 C2 18 3 CBYPASS 4 C1 2 VCC 1 C1+ VCC C1GND
RS-485 MODE V+ C2+ CHARGE PUMP C2VESD PROTECTION Z Y 20 19 C3 18 17 16 D DE485 ESD PROTECTION B A 15 14 RS-485 INPUTS 13 12 HDPLX MAX3160E RS-485/RS-232 11 LOGIC INPUT LOGIC INPUTS
C2
C4
LOGIC OUTPUTS
HDPLX 12
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11
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
MAX3161E Functional Diagram
RS-232 MODE VCC 1 C1 2 3 CBYPASS 4 RS-232 OUTPUT 5 ESD PROTECTION 6 7 RS-232 OUTPUT 8 9 LOGIC OUTPUTS 10 11 SHDN 12 FAST GND T1 V21 C4 20 19 18 17 16 15 HDPLX 14 RS-232 INPUTS LOGIC INPUTS RS-485 OUTPUTS 7 8 9 R0 LOGIC OUTPUT 10 11 SHDN 12 FAST R 5 6 C1+ VCC C1CHARGE PUMP V+ C2+ C224 C3 23 C2 22 3 CBYPASS 4 C1 2 VCC 1 C1+ VCC C1GND
RS-485 MODE V+ C2+ CHARGE PUMP C2V24 C3 23 C2 22 21 20 ESD PROTECTION Z Y LOGIC INPUTS 19 D DE485 18 17 ESD PROTECTION B A 16 RS-485 INPUTS 15 14 LOGIC INPUT
C4
T2 R1 R2
ESD PROTECTION
MAX3161E
HDPLX MAX3161E
RS-485/RS-232 13
RS-485/RS-232 13
12
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
MAX3162E Functional Diagram
Y R VCC 1 C1 2 3 CBYPASS 4 RS-232 5 OUTPUT 6 RS-485 OUTPUTS 7 RS-232 8 OUTPUT R1 9 10 11 RO LOGIC INPUT 12 RE485 R ESD PROTECTION LOGIC OUTPUTS R2 20 RS-232 INPUTS 19 B A 18 RS-485 INPUTS 17 DI TE232 MAX3162E 14 FAST RE-232 16 15 LOGIC INPUTS 3V DE485 Y VOD RDIFF Z CL ESD PROTECTION Z Y GND T1 24 23 D DE485 T2 211 LOGIC INPUTS 22 S2 RECEIVER OUTPUT V25 C4 TEST POINT CL 1k S1 1k VCC C1+ VCC C1CHARGE PUMP V+ C2+ C2VOD C3 27 C2 26 Z R VOC
MAX3160E/MAX3161E/MAX3162E
Test Circuits
28
Figure 1. RS-485/RS-422 Driver DC Test Load
Figure 2. RS-485/RS-422 and RS-232 Receiver Enable/Disable Timing Test Load
13 SHDN
Figure 3. RS-485/RS-422 Driver Timing Test Circuit
OUTPUT UNDER TEST
500 CL
S1
VCC
S2
Figure 4. RS-485/RS-422 Driver Enable/Disable Timing Test Load
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13
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
Test Circuits (continued)
+3V 0V INPUT 1.5V 1.5V +3V INPUT 1.5V 0V 1.5V
OUTPUT
VCC 50% 50% GND OUTPUT
V+ 0V V-
tPHL tRSKEW = | tPLH - tPHL |
tPLH
tPLH tSKEW = | tPLH - tPHL |
tPHL
Figure 5. RS-232 Receiver Propagation-Delay Timing
3V DI 0 1.5V tDPLH tDPHL 1.5V 1/2 VO
Figure 6. RS-232 Transmitter Propagation-delay Timing
3V DE485 0
1.5V
1.5V
Z VO Y VO 0 -VO 1/2 VO 10% tDR 90% VDIFF = Vy - Vz 90%
tDZL Y, Z VOL Y, Z 10% 2.3V 0 tDZH
tDLZ VOL + 0.5V
2.3V OUTPUT NORMALLY LOW OUTPUT NORMALLY HIGH
VDIFF
VOH - 0.5V tDHZ
tDF tDSKEW = | tDPLH - tDPHL |
Figure 7. RS-485/RS-422 Driver Propagation Delays
Figure 8. RS-485/RS-422 Driver Enable and Disable Times
RO
VOH VOL A B VCC/2 tRPHL INPUT tRSKEW = | tRPLH - tRPHL | OUTPUT tRPLH VCC/2
3V RE232 OR RE485 0
1.5V
1.5V
tRZL VCC RO
tRLZ VOL + 0.5V
1V -1V
1.5V OUTPUT NORMALLY LOW OUTPUT NORMALLY HIGH
RO 0
1.5V tRZH tRHZ
VOH - 0.5V
Figure 9. RS-485/RS-422 Receiver Propagation Delays
Figure 10. MAX3162 RS-485/RS-422 and RS-232 Receiver Enable and Disable Times
B VID A R RO
CL
Figure 11. RS-485/RS-422 Receiver Propagation Delays Test Circuit 14 ______________________________________________________________________________________
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
Detailed Description
The MAX3160E/MAX3161E/MAX3162E +3V to +5.5V, multiprotocol transceivers can be pin-configured in a number of RS-232 and RS-485/RE-422 interface combinations. These circuit configurations are ideal for the design of RS-232 to RS-485 converters, multiprotocol buses, or any application that requires both RS-232 and RS-485 transceivers. The slew rate of these devices is on-the-fly pin selectable, allowing reduced EMI data rates, or up to 10Mbps RS-485 communications. Power consumption can be reduced to 10nA by using the shutdown function, but the RS-232 receivers remain active allowing other devices to query the interface controller. A flow-through pinout and the space-saving SSOP packages (available in commercial and extended temperature ranges) facilitate board layout. MAX3161E The MAX3161E is a 2T X /2R X RS-232 transceiver in RS-232 mode or a single RS-485/RS-422 transceiver in RS-485 mode. When in RS-485 mode, the unused RS232 transmitter and receiver outputs are disabled. When in RS-232 mode, the RS-485 transmitter outputs are disabled and the RS-232 receiver inputs are 5k to GND. The RS-485 receiver inputs are always 1/8-unit load. Logic lines are shared between the two protocols and are used for signal inputs and as an RS-485 driver enable. MAX3162E The MAX3162E is a 2Tx/2Rx RS-232 transceiver and a single RS-485/RS-422 transceiver simultaneously. All drivers, receivers, and transmitters can be enabled or disabled by pin selection. All outputs are high-impedance when not activated. RS-232 receiver inputs are 5k when enabled, and RS-485 receiver inputs are 1/8-unit load.
MAX3160E/MAX3161E/MAX3162E
Device Selection
The MAX3160E/MAX3161E/MAX3162E contain RS-232 transceivers and an RS-485/RS-422 transceiver. The primary difference between the devices is the multiplexing of the I/O ports. The MAX3160E has common transmitter outputs and receiver inputs for its RS-232 and RS-485/RS-422 transceivers, and common digital I/O ports. The MAX3160E is optimized for multiprotocol operation on a single interface bus and comes in a 20-pin SSOP package. The MAX3161E has separate transmitter outputs and receiver inputs for its RS-232 and RS-485/RS-422 transceivers, and common digital I/O ports. The MAX3161E is optimized for multiplexing a single UART across two interface buses and is available in a 24-pin SSOP package. The MAX3162E has separate transmitter outputs and receiver inputs for its RS-232 and RS-485/RS-422 transceivers, and separate digital I/O ports. The MAX3162E is optimized for protocol translation between two interface buses and comes in a 28-pin SSOP package. See Tables 1-12, the Functional Diagrams, and the following descriptions for details on each device. MAX3160E The MAX3160E is a 2T X /2R X RS-232 transceiver in RS-232 mode, capable of RS-232-compliant communication. Assertion of RS-485/RS-232 converts the device to a single RS-485 transceiver by multiplexing the RS232 I/O ports to an RS-485 driver and receiver pair. The logic inputs now control the driver input and the driver enable. One logic output carries the RS-485 receiver output, and the other is tri-stated. The receiver input impedance is dependent on the device mode and is 1/4-unit load for RS-485 operation and 5k for RS-232 operation.
Fast-Mode Operation
The FAST control input is used to select the slew-rate limiting of the RS-232 transmitters and the RS-485/ RS-422 drivers. With FAST unasserted, the RS-232 transmitters and the RS-485/RS-422 driver are slew-rate limited to reduce EMI. RS-232 data rates up to 1Mbps and RS-485/RS-422 data rates up to 10Mbps are possible when FAST is asserted. FAST can be changed during operation without interrupting data communications.
Half-Duplex RS-485/RS-422 Operation
Asserting HDPLX places the MAX3160E/MAX3161E in half-duplex mode. The RS-485 receiver inputs are internally connected to the driver outputs. To receive RS-485 data, disable the RS-485 outputs by driving DE485 low. HDPLX has no affect on RS-232 operation.
Low-Power Shutdown
The MAX3160E/MAX3161E/MAX3162E have an activelow shutdown control input, SHDN. When SHDN is driven low, the charge pump and transmitters are shut down and supply current is reduced to 10nA. The RS-232 receiver outputs remain active if in RS-232 mode. The charge-pump capacitors must be recharged when coming out of shutdown before resuming operation in either RS-232 or RS-485/RS-422 mode (Figure 12).
Dual Charge-Pump Voltage Converter
The MAX3160E/MAX3161E/MAX3162E's internal power supply consists of a regulated dual charge pump that provides output voltages of +5.5V (doubling charge pump), and -5.5V (inverting charge pump), for input voltages (V CC) over the +3.0V to +5.5V range. The charge pumps operate in a discontinuous mode. If the
15
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
magnitude of either output voltage is less than +5.5V, the charge pumps are enabled. If the magnitude of both output voltages exceeds +5.5V, the charge pumps are disabled. Each charge pump requires a flying capacitor (C1, C2) and a reservoir capacitor (C3, C4) to generate the V+ and V- supplies (see the Functional Diagrams). The receivers convert RS-232 signals to CMOS-logic output levels. All receivers have inverting outputs that remain active in shutdown. The MAX3160E/MAX3161E/ MAX3162E permit their receiver inputs to be driven to 25V. Floating receiver input signals are pulled to ground through internal 5k resistors, forcing the outputs to a logic-high. The MAX3162E has transmitter and receiver enable pins that allow its outputs to be tri-stated.
RS-485/RS-422 Transceivers
The MAX3160E/MAX3161E/MAX3162E RS-485/RS-422 transceivers feature fail-safe circuitry that guarantees a logic-high receiver output when the receiver inputs are open or shorted, or when they are connected to a terminated transmission line with all drivers disabled (see the Fail-Safe Section). The MAX3160E/MAX3161E/ MAX3162E also feature pin-selectable reduced slewrate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission up to 250kbps The transmitters can operate at speeds up to 10Mbps with the slew-rate limiting disabled. Drivers are short-circuit current limited and thermally limited to protect them against excessive power dissipation. Half-duplex communication is enabled by driving HDPLX high (MAX3160E/MAX3161E.)
15kV ESD Protection
As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against ESD encountered during handling and assembly. The MAX3160E/ MAX3161E/MAX3162E receiver inputs and transmitter outputs have extra protection against static electricity found in normal operation. Maxim's engineers developed state-of-the-art structures to protect these pins against 15kV ESD, without damage. After an ESD event, the MAX3160E/MAX3161E/MAX3162E continue working without latchup. The receiver inputs and transmitter outputs are characterized for 15kV ESD protection using the Human Body Model ESD Test Conditions ESD performance depends on a number of conditions. Contact Maxim for a reliability report that documents test setup, methodology, and results. Human Body Model Figure 13a shows the Human Body Model, and Figure 13b shows the current waveform it generates when discharged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the device through a 1.5k resistor.
Fail-Safe
The MAX3160E/MAX3161E/MAX3162E guarantee a logic-high RS-485 receiver output when the receiver inputs are shorted or open, or when they are connected to a terminated transmission line with all drivers disabled. This is done by having the receiver threshold between -50mV and -200mV. If the differential receiver input voltage (A-B) is greater than or equal to -50mV, RO is logic-high. If A-B is less than or equal to -200mV, RO is logic-low. In the case of a terminated bus with all transmitters disabled, the receiver's differential input voltage is pulled to 0 by the termination. This results in a logic-high with a 50mV minimum noise margin.
RS-232 Transceivers
The MAX3160E/MAX3161E/MAX3162E RS-232 transmitters are inverting-level translators that convert CMOS-logic levels to 5V EIA/TIA-232-compliant levels. The transmitters are guaranteed at a 250kbps data rate in slew-rate limited mode (FAST = GND) with worst-case loads of 3k in parallel with 1000pF. Data rates up to 1Mbps can be achieved by asserting FAST. When powered down or in shutdown, the MAX3160E/ MAX3161E/MAX3162E outputs are high impedance and can be driven to 13.2V. The transmitter inputs do not have pullup resistors. Connect unused inputs to ground or VCC.
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
SHDN 5V/div T1OUT 2V/div GND T2OUT 2V/div HIGHVOLTAGE DC SOURCE RC 1M CHARGE-CURRENT LIMIT RESISTOR RD 1.5k DISCHARGE RESISTANCE DEVICE UNDER TEST
Cs 100pF
STORAGE CAPACITOR
40s/div
Figure 12. RS-232 Transmitter Outputs when Exiting Shutdown
Figure 13a. Human Body ESD Test Model
Machine Model The Machine Model for ESD testing uses a 200pF storage capacitor and zero-discharge resistance. It mimics the stress caused by handling during manufacturing and assembly. Of course, all pins (not just RS-485 inputs) require this protection during manufacturing. Therefore, the Machine Model is less relevant to the I/O ports than are the Human Body Model and IEC 1000-4-2.
IP 100% 90% AMPERES 36.8% 10% 0 0 tRL TIME
Ir
PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE)
Applications Information
Capacitor Selection
The capacitor type used for C1-C4 is not critical for proper operation; polarized or nonpolarized capacitors can be used. Ceramic chip capacitors with an X7R dielectric provide the best combination of performance, cost, and size. The charge pump requires 0.1F capacitors for 3.3V operation. For other supply voltages, see Table 13 for required capacitor values. Do not use values smaller than those listed in Table 13. Increasing the capacitor values reduces ripple on the transmitter outputs and slightly reduces power consumption. C2, C3, and C4 can be changed without changing C1's value. However, do not increase C1 without also increasing the values of C2, C3, C4, and CBYPASS to maintain the proper ratios to the other capacitors. When using the minimum required capacitor values, make sure the capacitance value does not degrade excessively with temperature or voltage. This is typical of Y5V and Z5U dielectric ceramic capacitors. If in doubt, use capacitors with a larger nominal value. The capacitor's equivalent series resistance (ESR), which
tDL CURRENT WAVEFORM
Figure 13b. Human Body Model Current Waveform
usually rises at low temperatures, influences the amount of ripple on V+ and V-.
Power-Supply Decoupling
In applications that are sensitive to power-supply noise, decouple VCC to ground with a capacitor of the same value as reservoir capacitors C2, C3, and C4. Connect the bypass capacitor as close to the IC as possible.
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17
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
RS-232 Transmitter Outputs when Exiting Shutdown
Figure 12 shows two transmitter outputs when exiting shutdown mode. As they become active, the two transmitter outputs are shown going to opposite RS-232 levels (one transmitter input is high, the other is low). Each transmitter is loaded with 3k in parallel with 1000pF. The transmitter outputs display no ringing or undesirable transients as they come out of shutdown. Note that the transmitters are enabled only when V- exceeds approximately -3V.
VCC CBYPASS
C1+ C1 C1C2+ C2 C2T_ IN
VCC
V+ C3
MAX3160E MAX3161E MAX3162E
VC4
High Data Rates
The MAX3160E/MAX3161E/MAX3162E maintain the RS-232 5V required minimum transmitter output voltage even at high data rates. Figure 14 shows a transmitter loopback test circuit. Figure 15 shows a loopback test result at 250kbps, and Figure 16 shows the same test at 1Mbps. Figure 15 demonstrates a single slew-rate limited transmitter driven at 250kbps (FAST = GND) into an RS-232 load in parallel with 1000pF. Figure 17 shows a single transmitter driven at 1Mbps (FAST asserted), loaded with an RS-232 receiver in parallel with 1000pF. These transceivers maintain the RS-232 5V minimum transmitter output voltage at data rates up to 1Mbps.
T_ OUT
R_ OUT
R_ IN
1000pF 5k VCC SHDN GND
Figure 14. Loopback Test Circuit
256 Transceivers on the Bus
The standard RS-485 receiver input impedance is 12k (one-unit load), and the standard driver can drive up to 32-unit loads. The MAX3160E has a 1/4-unit load receiver input impedance (48k), allowing up to 128 transceivers to be connected in parallel on one communication line. The MAX3161E/MAX3162E have a 1/8unit load receiver input impedance (96k), allowing up to 256 transceivers to be connected in parallel on one communication line. Any combination of these devices and/or other RS-485 transceivers with a total of 32-unit loads or fewer can be connected to the line.
The MAX3160E/MAX3161E/MAX3162E inputs are protected to RS-232 levels of 25V for the receiver inputs and 13V for the transmitter/driver outputs. This provides additional protection for the RS-485 transceivers against ground differential or faults due to miswiring.
RS-485/RS-422 Reduced EMI and Reflections
The MAX3160E/MAX3161E/MAX3162E can be configured for slew-rate limiting by pulling FAST low. This minimizes EMI and reduces reflections caused by improperly terminated cables. Operation in slew-rate limited mode reduces the amplitudes of high-frequency harmonics.
RS-485/RS-422 Driver Output Protection
Two mechanisms prevent excessive output current and power dissipation caused by faults or by bus contention. The first, a foldback current limit on the output stage, provides immediate protection against short circuits over the whole common-mode voltage range (see the Typical Operating Characteristics). The second, a thermal shutdown circuit, forces the driver outputs into a high-impedance state if the die temperature becomes excessive, typically over +150C.
RS-485/RS-422 Line Length vs. Data Length
The RS-485/RS-422 standard covers line lengths up to 4000ft. For line lengths greater than 4000ft, use the repeater application shown in Figure 17.
RS-232/RS-485 Protocol Translator
Figure 18 shows the MAX3162E configured as an RS-232/RS-485 protocol translator. The direction of translation is controlled through the RTS signal (R1IN). The single-ended RS-232 receiver input signal is translated to a differential RS-485 transmitter output. Similarly, a differential RS-485 receiver input signal is translated to a single-ended RS-232 transmitter output. RS-232 data received on R2IN is transmitted as an RS485 signal on Z and Y. RS-485 signals received on A and B are transmitted as an RS-232 signal on T1OUT.
Protection Against Wiring Faults
EIA/TIA-485 standards require a common input voltage range of -7V to +12V to prevent damage to the device.
18
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
TIN TOUT 5V/div
TIN TOUT 5V/div
ROUT
1s/div
ROUT
ROUT
1s/div
200ns/div
Figure 15. MAX3161E/MAX3162E RS-232 Loopback Test Result at 250kbps, FAST = Low
Figure 16. MAX3161E/MAX3162E RS-232 Loopback Test Result at 1Mbps, FAST = High
Multiprotocol Bus The Typical Operating Circuit shows a standard application for the MAX3160E. The MAX3160E's outputs are multiplexed between RS-232 and RS-485 protocols by a microprocessor (P). The P also directs the shutdown functions, enable lines, and the duplex of the MAX3160E. Data is transmitted to the MAX3100 UART through an SPITM port. The UART asynchronously transfers data through the MAX3160E to the pin-selected RS-232 or RS-485 protocal. See Table 14 for commonly used cable connections.
Multiprotocol Bus Multiplexer
The Typical Application Circuit shows the MAX3161E configured as a multiprotocol bus multiplexer. The MAX3161E separates the RS-232 and RS-485 lines, but shares the logic pins between modes. This application allows the P to monitor a point-to-point RS-232 bus, and a multidrop RS-485 interface. The MAX3100 UART asynchronously transfers data through the MAX3161E to the pin-selected RS-232 or RS-485 protocol.
SPI is a registered trademark of Motorola, Inc.
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
3.3V
MAX3160E MAX3161E MAX3162E A RO R RE485 B DATA IN
2 27 C2+ VCC C1+ 1 3 C2 100nF
120
CBYPASS 100nF
DE485 Z D Y 120 DATA OUT
RCV
26 13 5 10 23
C1 100nF
C2- MAX3162E C1SHDN T1OUT R2OUT DI R2IN R1IN RE232 TE232 FAST V+ GND T1IN
DI
24
NOTE: RE485 ON MAX3162E ONLY
TX RTS
19 20 15 16 14 28 C3 100nF
11 RO 9 R1OUT 12 RE485 22 DE485 A B Z Y V17 18 6 7 25 C4 100nF
Figure 17. RS-485 Line Repeater
Figure 18. Protocol Translator
20
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
RS-232 Transmitters Truth Tables
Table 1. MAX3160E
INPUTS SHDN 0 1 1 1 RS-485/ RS-232 X 0 0 1 DI/T1IN, DE485/T2IN X 0 1 X OUTPUTS Z(B)/T1OUT, Y(A)/T2OUT 1/8-unit load 1 0 RS-485 mode X 1 X SHDN X X X
RS-232 Receivers Truth Tables
Table 4. MAX3160E
INPUTS RS-485/ RS-232 0 0 0 B/R1IN, A/R2IN 0 1 Inputs open OUTPUTS R1OUT, RO/R2OUT 1 0 1 R1OUT High-impedance, RO/R2OUT in RS-485 mode
MAX3160E/MAX3161E/MAX3162E
Table 2. MAX3161E
INPUTS SHDN 0 1 1 1 RS-485/ RS-232 X 0 0 1 DI/T1IN, DE485/T2IN X 0 1 X OUTPUTS T1OUT, T2OUT High-impedance 1 0 High-impedance SHDN X X X RS-485/ RS-232 0 0 0 R1IN, R2IN 0 1 Inputs open
Table 5. MAX3161E
INPUTS OUTPUTS R1OUT, RO/R2OUT 1 0 1 R1OUT High-impedance, RO/R2OUT in RS-485 mode
Table 3. MAX3162E
SHDN 0 X 1 1 INPUTS TE232 X 0 1 1 T1IN,T2IN X X 0 1 OUTPUTS T1OUT, T2OUT High-impedance High-impedance 1 0 SHDN X X X X X 1 X
Table 6. MAX3162E
INPUTS RE232 1 0 0 0 R1IN, R2IN X 0 1 Inputs open OUTPUTS R1OUT, R2OUT High-impedance 1 0 1
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15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
RS-485/RS-422 Drivers Truth Tables
Table 7. MAX3160E
INPUTS SHDN 0 1 1 1 X R RS-485/RS - 2 3 2 X 1 1 1 0 DE485/T2IN X 0 1 1 X DI/T1IN X X 0 1 X Z(B)/T1OUT 1/8-unit load 1/8-unit load 1 0 RS-232 mode OUTPUTS Y(A)/T2OUT 1/8-unit load 1/8-unit load 0 1
Table 8. MAX3161E
INPUTS SHDN 0 X X 1 1 R RS-485/R S -2 3 2 X 0 X 1 1 DE485/T2IN X X 0 1 1 DI/T1IN X X X 0 1 Z(B) 1/8-unit load 1/8-unit load 1/8-unit load 1 0 OUTPUTS Y(A) 1/8-unit load 1/8-unit load 1/8-unit load 0 1
Table 9. MAX3162E
INPUTS SHDN 0 X 1 1 DE485 X 0 1 1 DI X X 0 1 Z High-impedance High-impedance 1 0 OUTPUTS Y High-impedance High-impedance 0 1
RS-485/RS-422 Receivers Truth Tables
Table 10. MAX3160E
INPUTS R RS-485/RS - 232 1 1 1 1 1 1 1 0 SHDN 0 1 1 1 1 1 1 X HDPLX X 0 0 0 1 1 1 X (A - B)* X -50mV -200mV Floating X X X X (Y - Z)* X X X X -50mV -200mV Floating X OUTPUT RO/R2OUT High-impedance up to VCC 1 0 1 1 0 1 RS-232 mode
*Y and Z correspond to pins Y(A)/T2OUT and Z(B)/T1OUT. A and B correspond to pins A/R2IN and B/R1IN. 22 ______________________________________________________________________________________
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
RS-485/RS-422 Receivers Truth Tables (continued)
Table 11. MAX3161E
INPUTS RS-485/RS-232 1 1 1 1 1 1 1 0 SHDN 0 1 1 1 1 1 1 X HDPLX X 0 0 0 1 1 1 X A-B X -50mV -200mV Floating X X X X Y(A) - Z(B) X X X X -50mV -200mV Floating X OUTPUT RO/R2OUT High-impedance up to VCC 1 0 1 1 0 1 RS-232 mode
MAX3160E/MAX3161E/MAX3162E
Table 12. MAX3162E
INPUTS SHDN 0 X 1 1 1 RE485 X 1 0 0 0 A-B X X -50mV -200mV Inputs OUTPUT RO High-impedance High-impedance 1 0 1
Table 13. Required Minimum Capacitance Values
SUPPLY VOLTAGE (V) +3.0 to +3.6 +4.5 to +5.5 +3.0 to +5.5 C1 (F) 0.1 0.047 0.1 C2, C3, C4, CBYPASS (F) 0.1 0.33 0.47
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23
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
Table 14. Cable Connections Commonly Used for EIA/TIA-232 and V.24 Asynchronous Interfaces
EIA/TIA-232 STANDARD DCD RD TD DTR SG DSR RTS CTS RI CONNECTOR PIN 1 2 3 4 5 6 7 8 9 MAX3160E MAX3161E MAX3162E EQUIVALENT -- R2IN T1OUT -- GND -- T2OUT R1IN -- PIN NUMBER MAX3160E -- 13 5 -- 4 -- 6 14 -- MAX3161E -- 17 5 -- 4 -- 8 18 -- MAX3162E -- 19 5 -- 4 -- 8 20 -- Data carrier detect Received data Transmitted data Data terminal ready Signal ground Data set ready Request to send (= DTE ready) Clear to send (= DCE ready) Ring indicator FUNCTION (AS SEEN BY DTE)
Typical Application Circuit
+3.3V
2 VCC
14 HDPLX RS-232 5 17 8 18
DB9
TX MAX3100 UART RX
13 12
DI/T1IN 20 10 19 9 R1OUT RO/R2OUT DE485/T2IN MAX3161E
T1OUT R2IN T2OUT R1IN
RTS CTS
11 10
1
RS-485 Y(A) RJ45
SPI GND 4 FAST 12
7
Z(B) RS-485/ 6 RS-232 SHDN 13 11
P
RS-485/RS-232
SHDN
MULTIPROTOCOL BUS MULTIPLEXER
24
______________________________________________________________________________________
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers
Pin Configurations
TOP VIEW
MAX3160E/MAX3161E/MAX3162E
C1+ 1 VCC 2 C1- 3 GND 4 Z(B)/T1OUT 5 Y(A)/T2OUT 6 R1OUT 7 RO/R2OUT 8 SHDN 9 FAST 10
20 V+ 19 C2+ 18 C217 V-
C1+ 1 VCC 2 C1- 3 GND 4 T1OUT 5 Z(B) 6 Y(A) 7 T2OUT 8 R1OUT 9 RO/R2OUT 10 SHDN 11
24 V+ 23 C2+ 22 C221 V-
C1+ 1 VCC 2 C1- 3 GND 4 T1OUT 5 Z6 Y7 T2OUT 8 R1OUT 9 R2OUT 10 RO 11 RE485 12 SHDN 13 FAST 14
28 V+ 27 C2+ 26 C225 V24 T1IN
MAX3160E
16 DI/T1IN 15 DE485/T2IN 14 B/R1IN 13 A/R2IN 12 HDPLX 11 RS-485/RS-232
MAX3161E
20 DI/T1IN 19 DE485/T2IN 18 R1IN 17 R2IN 16 B 15 A 14 HDPLX 13 RS-485/RS-232
MAX3162E
23 DI 22 DE485 21 T2IN 20 R1IN 19 R2IN 18 B 17 A 16 TE232 15 RE232
SSOP
FAST 12
SSOP
SSOP
Selector Guide
PART DUAL MODE No No Yes FLOWTHROUGH PINOUT Yes No Yes RS-485 INPUT UNIT LOADS 1/4 1/8 1/8
Chip Information
TRANSISTOR COUNT: 1805 PROCESS: CMOS
MAX3160E MAX3161E MAX3162E
______________________________________________________________________________________
25
15kV ESD-Protected, +3.0V to +5.5V, 10nA, RS-232/RS-485/RS-422 Multiprotocol Transceivers MAX3160E/MAX3161E/MAX3162E
Package Information
2 1
SSOP.EPS
INCHES DIM A A1 B C E H D E e H L MIN 0.068 0.002 0.010 MAX 0.078 0.008 0.015
MILLIMETERS MIN 1.73 0.05 0.25 MAX 1.99 0.21 0.38 D D D D D INCHES MIN 0.239 0.239 0.278 0.317 0.397 MAX 0.249 0.249 0.289 0.328 0.407 MILLIMETERS MIN 6.07 6.07 7.07 8.07 10.07 MAX 6.33 6.33 7.33 8.33 10.33 N 14L 16L 20L 24L 28L
0.20 0.09 0.004 0.008 SEE VARIATIONS 0.205 0.301 0.025 0 0.212 0.311 0.037 8 5.20 7.65 0.63 0 5.38 7.90 0.95 8 0.0256 BSC 0.65 BSC
N
A C B e D A1 L
NOTES: 1. D&E DO NOT INCLUDE MOLD FLASH. 2. MOLD FLASH OR PROTRUSIONS NOT TO EXCEED .15 MM (.006"). 3. CONTROLLING DIMENSION: MILLIMETERS. 4. MEETS JEDEC MO150. 5. LEADS TO BE COPLANAR WITHIN 0.10 MM.
PROPRIETARY INFORMATION TITLE:
PACKAGE OUTLINE, SSOP, 5.3 MM
APPROVAL DOCUMENT CONTROL NO. REV.
21-0056
1 1
C
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
26 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.

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