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1 ? fn4878.5 ICL3225, icl3245 1 microamp, +3v to +5.5v, 1mbps, rs-232 transceivers with enhanced automatic powerdown the intersil icl32xx devices are 3.0v to 5.5v powered rs-232 transmitters/receivers which meet ela/tia-232 and v.28/v.24 specifications, even at v cc = 3.0v. targeted applications are pdas, palmto ps, and notebook and laptop computers where the low operational, and even lower standby, power consumption is critical. efficient on-chip charge pumps, coupled with manual and enhanced automatic powerdown functions, reduce the standby supply current to a 1 a trickle. small footprint packaging, and the use of small, low value capacitors ensure board space savings as well. data rates greater than 1mbps are guaranteed at worst case load c onditions. this family is fully compatible with 3.3v only syst ems, mixed 3.3v and 5.0v systems, and 5.0v only systems. the icl3245 is a 3 driver, 5 receiver device that provides a complete serial port suitable for laptop or notebook computers. it also includes a noninverting always-active receiver for ?wake-up? capability. these devices, feature an enhanced automatic powerdown function which powers down the on-chip power- supply and driver circuits. this occurs when all receiver and transmitter inputs detect no signal transitions for a period of 30s. these devices power back up, automatically, whenever they sense a transition on any transmitter or receiver input. table 1 summarizes the features of the device represented by this data sheet, while application note an9863 summarizes the features of ea ch device comprising the icl32xx 3v family. features ? 15kv esd protected (human body model) ? manual and enhanced automatic powerdown features ? drop in replacements for max3225, max3245 ? meets eia/tia-232 and v.28/v .24 specifications at 3v ? latch-up free ? on-chip voltage converters require only four external 0.1 f capacitors ? guaranteed mouse driveability (icl3245) ? ?ready to transmit? indi cator output (ICL3225) ? receiver hysteresis for improved noise immunity ? guaranteed minimum data rate . . . . . . . . . . . . . . 1mbps ? low skew at transmitter/receiver input trip points. . . 10ns ? guaranteed minimum slew rate . . . . . . . . . . . . . . 24v/ s ? wide power supply range . . . . . . . single +3v to +5.5v ? low supply current in powerdow n state. . . . . . . . . . .1 a applications ? any system requiring rs-232 communication ports - battery powered, hand-hel d, and portable equipment - laptop computers, notebooks, palmtops - modems, printers and other peripherals - digital cameras - cellular/mobile phones related literature ? technical brief tb363 ?guidelines for handling and processing moisture sensit ive surface mount devices (smds)? table 1. summary of features part number no. of tx. no. of rx. no. of monitor rx. (r outb ) data rate (kbps) rx. enable function? ready output? manual power- down? enhanced automatic powerdown function? ICL3225 2 2 0 1000 no yes yes yes icl3245 3 5 1 1000 no no yes yes data sheet june 2004 caution: these devices are sensitive to electrosta tic discharge; follow proper ic handling procedures. 1-888-intersil or 321-724-7143 | intersil (and design) is a registered trademark of intersil americas inc. copyright ? intersil americas inc. 2000, 2001, 2003, 2004. all rights reserved all other trademarks mentioned are the property of their respective owners.
2 pinouts ICL3225 (pdip, ssop) top view icl3245 (ssop, tssop) top view ordering information part no. temp. range (c) package pkg. dwg. # ICL3225ca 0 to 70 20 ld ssop m20.209 ICL3225ca-t 0 to 70 20 ld ssop tape and reel m20.209 ICL3225cp 0 to 70 20 ld pdip e20.3 ICL3225ia -40 to 85 20 ld ssop m20.209 ICL3225ia-t -40 to 85 20 ld ssop tape and reel m20.209 icl3245ca 0 to 70 28 ld ssop m28.209 icl3245ca-t 0 to 70 28 ld ssop tape and reel m28.209 icl3245iv -40 to 85 28 ld tssop m28.173 icl3245iv-t -40 to 85 28 ld tssop tape and reel m28.173 ordering information (continued) part no. temp. range (c) package pkg. dwg. # ready c1+ v+ c1- c2+ c2- v- t2 out r2 in forceoff gnd t1 out r1 in r1 out t1 in invalid v cc forceon t2 in 20 19 18 17 16 15 14 13 12 11 1 2 3 4 5 6 7 8 9 10 r2 out c2+ c2- v- r1 in r2 in r3 in r4 in r5 in t1 out t3 out t3 in t2 in t1 in c1+ v cc gnd c1- forceon invalid r1 out r2 out r3 out r4 out r5 out v+ forceoff r2 outb 28 27 26 25 24 23 22 21 20 19 18 17 16 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 t2 out ICL3225, icl3245
3 pin descriptions pin function v cc system power supply input (3.0v to 5.5v). v+ internally generated positiv e transmitter supply (+5.5v). v- internally generated negative transmitter supply (-5.5v). gnd ground connection. c1+ external capacitor (voltage do ubler) is connected to this lead. c1- external capacitor (voltage do ubler) is connected to this lead. c2+ external capacitor (voltage inverter) is connected to this lead. c2- external capacitor (voltage inverter) is connected to this lead. t in ttl/cmos compatible transmitter inputs. t out rs-232 level (nominally 5.5v) transmitter outputs. r in rs-232 compatible receiver inputs. r out ttl/cmos level receiver outputs. r outb ttl/cmos level, noninverting, always enabled receiver outputs. invalid active low output that indicates if no valid rs -232 levels are present on any receiver input. ready active high output that indicates when the icl32xxe is ready to transmit (i.e., v- -4v) forceoff active low to shut down transmitters and on-chip power supply. this overrides any automatic circuitry and forceon (see table 2) . forceon active high input to override automatic powerdown ci rcuitry thereby keeping transmitters active. (forceoff must be high). typical operating circuits ICL3225 19 v cc t1 out t2 out t1 in t2 in t 1 t 2 0.1 f + 0.1 f + 0.1 f 13 12 17 8 2 4 3 7 v+ v- c1+ c1- c2+ c2- + 0.1 f 5 6 r1 out r1 in 16 5k ? r2 out r2 in 9 10 5k ? 15 c 1 c 2 + c 3 c 4 ready 1 gnd +3.3v + 0.1 f 18 ttl/cmos logic levels rs-232 levels r 1 r 2 forceon forceoff 14 20 v cc 11 invalid to power control logic ICL3225, icl3245
4 icl3245 typical operating circuits (continued) 26 v cc t1 out t2 out t3 out t1 in t2 in t3 in t 1 t 2 t 3 0.1 f + 0.1 f + 0.1 f 14 13 9 10 12 11 28 24 27 3 v+ v- c1+ c1- c2+ c2- + 0.1 f 1 2 r1 out r1 in 4 5k ? r2 out r2 in 5 18 5k ? r3 out r3 in 6 17 5k ? r4 out r4 in 7 16 5k ? r5 out r5 in r 5 8 15 5k ? 19 r2 outb c 1 c 2 + c 3 c 4 forceon forceoff 23 gnd 22 +3.3v + 0.1 f 20 25 v cc ttl/cmos logic levels rs-232 levels rs-232 levels r 1 r 2 r 3 r 4 21 invalid to power control logic ICL3225, icl3245
5 absolute maximum rati ngs thermal information v cc to ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3v to 6v v+ to ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3v to 7v v- to ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3v to -7v v+ to v- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14v input voltages t in , forceoff , forceon . . . . . . . . . . . . . . . . . . -0.3v to 6v r in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25v output voltages t out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2v r out , invalid , ready . . . . . . . . . . . . . . . . -0.3v to v cc +0.3v short circuit duration t out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . continuous esd rating . . . . . . . . . . . . . . . . . . . . . . . . . see specification table thermal resistance (typical, note 1) ja (c/w) 20 ld pdip package . . . . . . . . . . . . . . . . . . . . . . . . 80 20 ld ssop package . . . . . . . . . . . . . . . . . . . . . . . 135 28 ld ssop package . . . . . . . . . . . . . . . . . . . . . . . 100 28 ld tssop package . . . . . . . . . . . . . . . . . . . . . . 125 maximum junction temperature (plastic package) . . . . . . . 150c maximum storage temperature range . . . . . . . . . . -65c to 150c maximum lead temperature (soldering 10s) . . . . . . . . . . . . 300c (ssop, tssop - lead tips only) operating conditions temperature range icl32xxc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0c to 70c icl32xxi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40c to 85c caution: stresses above those listed in ?abs olute maximum ratings? may cause permanent dam age to the device. this is a stress o nly rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. note: 1. ja is measured with the component mounted on a low effective ther mal conductivity test board in free air. see tech brief tb379 fo r details. electrical specifications test conditions: v cc = 3v to 5.5v, c 1 - c 4 = 0.1 f; unless otherwise specified. typicals are at t a = 25c parameter test conditions temp (c) min typ max units dc characteristics supply current, automatic powerdown all r in open, forceon = gnd, forceoff = v cc 25 - 1.0 10 a supply current, powerdown forceoff = gnd 25 - 1.0 10 a supply current, automatic powerdown disabled all outputs unloaded, forceon = forceoff = v cc icl3245, v cc = 3.0v 25 - 0.3 1.0 ma icl322x, v cc = 3.15v 25 - 0.3 1.0 ma logic and transmitter inputs and receiver outputs input logic threshold low t in , forceon, forceoff full - - 0.8 v input logic threshold high t in , forceon, forceoff v cc = 3.3v full 2.0 - - v v cc = 5.0v full 2.4 - - v transmitter input hysteresis 25 - 0.5 - v input leakage current t in , forceon, forceoff full - 0.01 1.0 a output leakage current forceoff = gnd full - 0.05 10 a output voltage low i out = 1.6ma full - - 0.4 v output voltage high i out = -1.0ma full v cc -0.6 v cc -0.1 - v receiver inputs input voltage range full -25 - 25 v input threshold low v cc = 3.3v 25 0.6 1.2 - v v cc = 5.0v 25 0.8 1.5 - v input threshold high v cc = 3.3v 25 - 1.5 2.4 v v cc = 5.0v 25 - 1.8 2.4 v input hysteresis 25 - 0.5 - v input resistance 25 3 5 7 k ? transmitter outputs output voltage swing all transmitter outputs loaded with 3k ? to ground full 5.0 5.4 - v output resistance v cc = v+ = v- = 0v, transmitter output = 2v full 300 10m - ? output short-circuit current full - 35 60 ma output leakage current v out = 12v, v cc = 0v or 3v to 5.5v automatic powerdown or forceoff = gnd full - - 25 a ICL3225, icl3245
6 mouse driveability transmitter output voltage (see figure 11) t1 in = t2 in = gnd, t3 in = v cc , t3 out loaded with 3k ? to gnd, t1 out and t2 out loaded with 2.5ma each full 5--v enhanced automatic powerdown (forceon = gnd, forceoff = v cc ) receiver input thresholds to invalid high see figure 6 full -2.7 - 2.7 v receiver input thresholds to invalid low see figure 6 full -0.3 - 0.3 v invalid , ready output voltage low i out = 1.6ma full - - 0.4 v invalid , ready output voltage high i out = -1.0ma full v cc -0.6 - - v receiver positive or negative threshold to invalid high delay (t invh ) 25 - 1 - s receiver positive or negative threshold to invalid low delay (t invl ) 25 - 30 - s receiver or transmitter edge to transmitters enabled delay (t wu ) note 2 25 - 100 - s receiver or transmitter edge to transmitters disabled delay (t autopwdn ) note 2 full 15 30 60 sec timing characteristics maximum data rate r l = 3k ?, one transmitter switching c l = 1000pf full 250 - - kbps v cc = 3v to 4.5v, c l = 250pf full 1000 - - kbps v cc = 4.5v to 5.5v, c l = 1000pf full 1000 - - kbps receiver propagation delay receiver input to receiver output, c l = 150pf t phl 25 - 0.15 - s t plh 25 - 0.15 - s receiver output enable time normal operation 25 - 200 - ns receiver output disable time normal operation 25 - 200 - ns transmitter skew t phl - t plh (note 3) 25 - 25 - ns receiver skew t phl - t plh (note 3) 25 - 50 - ns transition region slew rate v cc = 3.3v, r l = 3k ? to 7k ?, measured from 3v to -3v or -3v to 3v, c l = 150pf to 1000pf 25 24 - 150 v/ s esd performance rs-232 pins (t out , r in ) human body model 25 - 15 - kv iec1000-4-2 contact discharge 25 - 8-kv iec1000-4-2 air gap discharge 25 - > 8-kv all other pins human body model 25 - 2.5 - kv notes: 2. an ?edge? is defined as a transition through t he transmitter or receiver input thresholds. 3. skews are measured at the receiver input switching points (1.4v). electrical specifications test conditions: v cc = 3v to 5.5v, c 1 - c 4 = 0.1 f; unless otherwise specified. typicals are at t a = 25c (continued) parameter test conditions temp (c) min typ max units ICL3225, icl3245
7 detailed description these icl32xx interface ics operate from a single +3v to +5.5v supply, guarantee a 1mbps minimum data rate, require only four small external 0.1 f capacitors, feature low power consumption, and meet all ela rs-232c and v.28 specifications. the circuit is di vided into three sections: the charge pump, the transmitters, and the receivers. charge-pump intersil?s new icl32xx family utilizes regulated on-chip dual charge pumps as voltage doublers, and voltage inverters to generate 5.5v transmitter supplies from a v cc supply as low as 3.0v. this allows these devices to maintain rs-232 compliant output levels over the 10% tolerance range of 3.3v powered systems. the effi cient on-chip power supplies require only four small, external 0.1 f capacitors for the voltage doubler and inverter functions at v cc = 3.3v. see the ?capacitor selection? section, and table 3 for capacitor recommendations for other operating conditions. the charge pumps operate discontinuously (i .e., they turn off as soon as the v+ and v- supplies are pumped up to the nominal values), resulting in significant power savings. transmitters the transmitters are proprietary, low dropout, inverting drivers that translate ttl/cm os inputs to eia/tia-232 output levels. coupled with the on-chip 5.5v supplies, these transmitters deliver tr ue rs-232 levels over a wide range of single supply system voltages. transmitter outputs disable and assume a high impedance state when the device enters the powerdown mode (see table 2). these outputs may be driven to 12v when disabled. all devices guarantee a 1mbps data rate for full load conditions (3k ? and 250pf), v cc 3.0v, with one transmitter operating at full speed. under more typical conditions of v cc 3.3v, r l = 3k ? , and c l = 250pf, one transmitter easily operates at 1.4mbps. transmitter skew is extremely low on these device s, and is specified at the receiver input trip points (1.4 v), rather than the arbitrary 0v crossing point typical of other rs-232 families. transmitter inputs float if left unconnected, and may cause i cc increases. connect unused inputs to gnd for the best performance. receivers all the icl32xx devices contain standard inverting receivers, but only the icl3245 receivers can three-state, via the forceoff control line. additionally, the icl3245 includes a noninverting (monitor) receiver (denoted by the r outb label) that is always acti ve, regardless of the state of any control lines. both receiver types convert rs-232 signals to cmos output levels and accept inputs up to 25v while presenting the required 3k ? to 7k ? input impedance (see figure 1) even if the power is off (v cc = 0v). the receivers? schmitt trigger input stage uses hysteresis to increase noise immunity and decrease errors due to slow input signal transitions. the icl3245 inverting receivers disable during forced (manual) powerdown, but not during automatic powerdown (see table 2). conversely, the monitor receiver remains active even during manual powerdown making it extremely useful for ring indicator monitoring. standard receivers driving powered down peripherals must be disabled to prevent current flow through the peripheral?s protection diodes (see figures 2 and 3). this renders them useless for wake up functions, but the corresponding monitor receiver can be dedicated to this task as shown in figure 3. r xout gnd v rout v cc 5k ? r xin -25v v rin +25v gnd v cc figure 1. inverting receiver connections figure 2. power drain through powered down peripheral old v cc powered gnd shdn = gnd v cc rx tx v cc current v out = v cc flow rs-232 chip down uart figure 3. disabled receivers prevent power drain icl3245 transition r x t x r2 outb r2 out t1 in forceoff = gnd v cc v cc to r2 in t1 out v out = hi-z powered detector down uart wake-up logic ICL3225, icl3245
8 powerdown functionality this 3v family of rs-232 interface devices requires a nominal supply current of 0.3ma during normal operation (not in powerdown mode). this is considerably less than the 5ma to 11ma current required of 5v rs-232 devices. the already low current requirement drops significantly when the device enters powerdown mode. in powerdown, supply current drops to 1 a, because the on-chip charge pump turns off (v+ collapses to v cc , v- collapses to gnd), and the transmitter outputs three-stat e. inverting receiver outputs may or may not disable in powerdown; refer to table 2 for details. this micro-power mode makes these devices ideal for battery powered and portable applications. software controlled (manual) powerdown these three devices allow the us er to force the ic into the low power, standby state, and utilize a two pin approach where the forceon and forceoff inputs determine the ic?s mode. for always enabled operation, forceon and forceoff are both strapped high. to switch between active and powerdown modes, under logic or software control, only the forceoff input need be driven. the forceon state isn?t cr itical, as forceoff dominates over forceon. nevertheless, if strictly manual control over powerdown is desired, the user must strap forceon high to disable the enhanced automatic powerdown circuitry. icl3245 inverting (standard) receiver outputs also disable when the device is in powerdown, thereby eliminating the possible current path through a shutdown peripheral?s input protection diode (see figures 2 and 3). connecting forceoff and forceon together disables the enhanced automatic powerdown feature, enabling them to function as a manual shutdown input (see figure 4). table 2. powerdown logic truth table rcvr or xmtr edge within 30s? forceoff input forceon input transmitter outputs receiver outputs (note 4) r outb outputs rs-232 level present at receiver input? invalid output mode of operation ICL3225 no h h active active n.a. no l normal operation (enhanced auto powerdown disabled) no h h active active n.a. yes h yes h l active active n.a. no l normal operation (enhanced auto powerdown enabled) yes h l active active n.a. yes h no h l high-z active n.a. no l powerdown due to enhanced auto powerdown logic no h l high-z active n.a. yes h x l x high-z active n.a. no l manual powerdown x l x high-z active n.a. yes h icl322x - invalid driving forceon and forceoff (emulates automatic powerdown) x note 5 note 5 active active n.a. yes h normal operation x note 5 note 5 high-z active n.a. no l forced auto powerdown icl3245 no h h active active active no l n ormal operation (enhanced auto powerdown disabled) no h h active active active yes h yes h l active active active no l n ormal operation (enhanced auto powerdown enabled) yes h l active active active yes h no h l high-z active active no l powerdown due to enhanced auto powerdown logic no h l high-z active active yes h x l x high-z high-z active no l manual powerdown x l x high-z high-z active yes h icl3245 - invalid driving forceon and forceoff (emulates automatic powerdown) x note 5 note 5 active active active yes h normal operation x note 5 note 5 high-z high-z active no l forced auto powerdown notes: 4. applies only to the icl3245. 5. input is connected to invalid output. ICL3225, icl3245
9 with any of the above control schemes, the time required to exit powerdown, and resume transmission is only 100 s. when using both manual and enhanced automatic powerdown (forceon = 0), the icl32xx won?t power up from manual powerdown until both forceoff and forceon are driven high, or until a transition occurs on a receiver or transmitter input. figure 5 illustrates a circuit for ensuring that the icl32xx powers up as soon as forceoff switches high. the rising edge of the master powerdown signal forces the device to power up, and the icl32xx returns to enhanced automatic powerdown mode an rc time constant after this rising edge. the time constant isn?t critical, because the icl32xx remains powered up for 30 seconds after the forceon falling edge, even if there are no signal trans itions. this gives slow-to-wake systems (e.g., a mouse) plenty of time to start transmitting, and as long as it starts transmitti ng within 30 seconds both systems remain enabled. invalid output the invalid output always indicates (see table 2) whether or not 30 s have elapsed with invalid rs-232 signals (see figures 6 and 8) persisting on all of the receiver inputs, giving the user an easy way to determine when the interface block should power down. invalid receiver levels occur whenever the driving peripheral?s outputs are shut off (powered down) or when the rs-232 interface cable is disconnected. in the case of a disconnected interface cable where all the receiver inputs are floating (but pulled to gnd by th e internal receiver pull down resistors), the invalid logic detects the invalid levels and drives the output low. the pow er management logic then uses this indicator to power down the interface block. reconnecting the cable restores valid levels at the receiver inputs, invalid switches high, and the power ma nagement logic wakes up the interface block. invalid can also be used to indicate the dtr or ring indicator signal, as long as the other receiver inputs are floating, or driven to gnd (as in the case of a powered down driver). enhanced automatic powerdown even greater power savings is available by using these devices which feature an enhanced automatic powerdown function. when the enhanced powerdown logic determines that no transitions have occu rred on any of the transmitter nor receiver inputs for 30 seconds, the charge pump and transmitters powerdown, ther eby reducing supply current to 1 a. the icl32xx automatically powers back up whenever it detects a transition on one of these inputs. this automatic powerdown feature provides additional system power savings without changes to t he existing operating system. enhanced automatic powerdown operates when the forceon input is low, and the forceoff input is high. tying forceon high disables automatic powerdown, but manual powerdown is always available via the overriding forceoff input. table 2 summarizes the enhanced automatic powerdown functionality. figure 4. connections for manual powerdown when no valid receiver signals are present pwr forceoff invalid cpu i/o forceon icl32xx mgt logic uart figure 5. circuit to ensure immediate power up when exiting forced powerdown forceoff forceon power master powerdown line 1m ? 0.1 f management unit icl32xx figure 6. definition of valid rs-232 receiver levels 0.3v -0.3v -2.7v 2.7v invalid level - invalid = 0 valid rs-232 level - invalid = 1 valid rs-232 level - invalid = 1 indeterminate indeterminate figure 7. enhanced automatic powerdown logic 30s timer s r forceoff autoshdn forceon r_in t_in edge detect edge detect ICL3225, icl3245
10 figure 7 illustrates the enhanced powerdown control logic. note that once the icl32xx enters powerdown (manually or automatically), the 30 second timer remains timed out (set), keeping the icl32xx powered down until forceon transitions high, or until a transition occurs on a receiver or transmitter input. the invalid output signal switches low to indicate that invalid levels have persisted on all of the receiver inputs for more than 30 s (see figure 8), but th is has no direct effect on the state of the icl32xx (see the next sections for methods of utilizing invalid to power down the device). invalid switches high 1 s after detecting a valid rs-232 level on a receiver input. invalid operates in all modes (forced or automatic powerdown, or forced on), so it is also useful for systems employing manual powerdown circuitry. the time to recover from automatic powerdown mode is typically 100 s. emulating standard automatic powerdown if enhanced automatic powerdown isn?t desired, the user can implement the standard aut omatic powerdown feature (mimics the function on the icl3221/icl3223/icl3243) by connecting the invalid output to the forceon and forceoff inputs, as shown in figure 9. after 30 s of invalid receiver levels, invalid switches low and drives the icl32xx into a forced powerdown condition. invalid switches high as soon as a rece iver input senses a valid rs- 232 level, forcing the icl32xx to power on. see the ?invalid driving forceon and forceoff ? section of table 2 for an operational summary. this operational mode is perfect for handheld devices that communicate with another computer via a detac hable cable. detaching the cable allows the internal receiver pull-down resistors to pull the inputs to gnd (an invalid rs-232 level), causing the 30 s timer to time-out and drive the ic into powerdown. reconnecting the cable restores valid levels, causing the ic to power back up. hybrid automatic powerdown options for devices which communicate only through a detachable cable, connecting invalid to forceoff (with forceon = 0) may be a desirable configuration. while the cable is attached invalid and forceoff remain high, so the enhanced automatic powerdown logic powers down the rs- 232 device whenever there is 30 seconds of inactivity on the receiver inputs transmitter outputs invalid output v+ v cc 0 v- t invl t invh figure 8. enhanced automatic powerdown, invalid and ready timing diagrams ready output transmitter inputs t wu t autopwdn t autopwdn t wu invalid region } figure 9. connections fo r automatic powerdown when no valid receiver signals are present forceoff invalid cpu i/o forceon icl32xx uart ICL3225, icl3245
11 receiver and transmitter inputs. detaching the cable allows the receiver inputs to drop to an invalid level (gnd), so invalid switches low and forces the rs-232 device to power down. the icl32xx remains powered down until the cable is reconnected (invalid = forceoff = 1) and a transition occurs on a receiver or transmitter input (see figure 7). for immediate power up when the cable is reattached, connect forceon to forceoff through a network similar to that shown in figure 5. ready output (ICL3225 only) the ready output indicates that the icl322x is ready to transmit. ready switches low whenever the device enters powerdown, and switches back high during power-up when v- reaches -4v or lower. capacitor selection the charge pumps require 0.1 f capacitors for 3.3v operation. for other supply voltages refer to table 3 for capacitor values. do not use va lues smaller than those listed in table 3. increasing the capacitor values (by a factor of 2) reduces ripple on the transmitter outputs and slightly reduces power consumption. c 2 , c 3 , and c 4 can be increased without increasing c 1 ?s value, however, do not increase c 1 without also increasing c 2 , c 3 , and c 4 to maintain the proper ratios (c 1 to the other capacitors). when using minimum required capacitor values, make sure that capacitor values do not degrade excessively with temperature. if in dou bt, use capacitors wit h a larger nominal value. the capacitor?s equivalent series resistance (esr) usually rises at low temperatures and it influences the amount of ripple on v+ and v-. power supply decoupling in most circumstances a 0.1 f bypass capacitor is adequate. in applications that are particularly sensitive to power supply noise, decouple v cc to ground with a capacitor of the same value as the charge-pump capacitor c 1 . connect the bypass capac itor as close as possible to the ic. operation down to 2.7v icl32xxe transmitter outputs meet rs-562 levels ( 3.7v), at full data rate, with v cc as low as 2.7v. rs-562 levels typically ensure inter operability with rs-232 devices. transmitter outputs when exiting powerdown figure 10 shows the response of two transmitter outputs when exiting powerdown mode. as they activate, the two transmitter outputs properly go to opposite rs-232 levels, with no glitching, ringing, nor undesirable transients. each transmitter is loaded with 3k ? in parallel with 2500pf. note that the transmitters enable only when the magnitude of the supplies exceed approximately 3v. mouse driveability the icl3245 is specifically designed to power a serial mouse while operating from low voltage supplies. figure 11 shows the transmitter output voltages under increasing load current. the on-chip switching regulator ensures the transmitters will supply at least 5v during worst case conditions (15ma for paralleled v+ transmitters, 7.3ma for single v- transmitter). table 3. required capacitor values v cc (v) c 1 ( f) c 2 , c 3 , c 4 ( f) 3.0 to 3.6 0.1 0.1 4.5 to 5.5 0.047 0.33 3.0 to 5.5 0.1 0.47 time (20 s/div.) t1 t2 2v/div 5v/div. v cc = +3.3v forceoff figure 10. transmitter outputs when exiting powerdown c1 - c4 = 0.1 f 5v/div. ready figure 11. transmitter output voltage vs load current (per transmitter, i.e., double current axis for total v out+ current) transmitter output voltage (v) load current per transmitter (ma) 0246810 -6 -4 -2 0 2 4 6 -5 -3 -1 1 3 5 13579 v out + v out - v cc v out + v out - t1 t2 t3 v cc = 3.0v icl3245 ICL3225, icl3245
12 high data rates the icl32xx maintain the rs-232 5v minimum transmitter output voltages even at high data rates. figure 12 details a transmitter loopback test circuit, and figure 13 illustrates the loopback test result at 250kbps. for this test, all transmitters were simultaneously driving rs-232 loads in parallel with 1000pf, at 250kbps. figure 14 shows the loopback results for a single transmitter driving 250pf and an rs-232 load at 1mbps. the static transmitters were also loaded with an rs-232 receiver. interconnection with 3v and 5v logic the icl32xxe directly interfac es with 5v cmos and ttl logic families. nevertheless, with the icl32xx at 3.3v, and the logic supply at 5v, ac, hc, and cd4000 outputs can drive icl32xx inputs, but icl32 xx outputs do not reach the minimum v ih for these logic families. see table 4 for more information. figure 12. transmitter loopback test circuit figure 13. loopback test at 250kbps (c l = 1000pf) icl32xx v cc c 1 c 2 c 4 c 3 + + + + c l v+ v- 5k t in r out c1+ c1- c2+ c2- r in t out + v cc 0.1 f v cc forceoff forceon t1 in t1 out r1 out 2 s/div. v cc = +3.3v 5v/div. c1 - c4 = 0.1 f figure 14. loopback test at 1mbps (c l = 250pf) table 4. logic family compatibility with various supply voltages system power-supply voltage (v) v cc supply voltage (v) compatibility 3.3 3.3 compatible with all cmos families. 5 5 compatible with all ttl and cmos logic families. 5 3.3 compatible with act and hct cmos, and with ttl. icl32xx outputs are incompatible with ac, hc, and cd4000 cmos inputs. t1 in t1 out r1 out 0.5 s/div. 5v/div. v cc = +3.3v c1 - c4 = 0.1 f ICL3225, icl3245
13 typical performance curves v cc = 3.3v, t a = 25c figure 15. transmitter output voltage vs load capacitance figure 16. slew rate vs load capacitance figure 17. supply current vs load capacitance when transmitting data figure 18. supply current vs load capacitance when transmitting data -6 -4 -2 0 2 4 6 1000 2000 3000 4000 5000 0 load capacitance (pf) transmitter output voltage (v) 1 transmitter at 1mbps v out + v out - other transmitters at 30kbps load capacitance (pf) slew rate (v/ s) 0 1000 2000 3000 4000 5000 0 10 30 50 110 -slew +slew 70 90 0 1000 2000 3000 4000 5000 load capacitance (pf) supply current (ma) 10 20 30 40 50 80 60 70 90 250kbps 120kbps ICL3225 1mbps 10 20 30 40 50 80 60 70 0 1000 2000 3000 4000 5000 load capacitance (pf) supply current (ma) 120kbps 1mbps 250kbps 90 icl3245 ICL3225, icl3245
14 die characteristics substrate potential (powered up) gnd transistor count ICL3225: 937 icl3245: 1109 process si gate cmos figure 19. supply curre nt vs supply voltage typical performance curves v cc = 3.3v, t a = 25c (continued) supply current (ma) 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 0 0.5 1.0 1.5 2.0 supply voltage (v) 2.5 3.0 3.5 no load all outputs static ICL3225, icl3245
15 ICL3225, icl3245 dual-in-line plastic packages (pdip) notes: 1. controlling dimensions: inch. in case of conflict between english and metric dimensions, the inch dimensions control. 2. dimensioning and tolerancing per ansi y14.5m - 1982. 3. symbols are defined in the ?mo series symbol list? in section 2.2 of publication no. 95. 4. dimensions a, a1 and l are measured with the package seated in jedec seating plane gauge gs - 3. 5. d, d1, and e1 dimensions do not include mold flash or protrusions. mold flash or protrusions shal l not exceed 0.010 inch (0.25mm). 6. e and are measured with the leads constrained to be perpen- dicular to datum . 7. e b and e c are measured at the lead tips with the leads uncon- strained. e c must be zero or greater. 8. b1 maximum dimensions do not include dambar protrusions. dam- bar protrusions shall not exceed 0.010 inch (0.25mm). 9. n is the maximum number of terminal positions. 10. corner leads (1, n, n/2 and n/2 + 1) for e8.3, e16.3, e18.3, e28.3, e42.6 will have a b1 dimension of 0.030 - 0.045 inch (0.76 - 1.14mm). e a -c- c l e e a c e b e c -b- e1 index 12 3 n/2 n area seating base plane plane -c- d1 b1 b e d d1 a a2 l a1 -a- 0.010 (0.25) c a m bs e20.3 (jedec ms-001-ad issue d) 20 lead dual-in-line plastic package symbol inches millimeters notes min max min max a - 0.210 - 5.33 4 a1 0.015 - 0.39 - 4 a2 0.115 0.195 2.93 4.95 - b 0.014 0.022 0.356 0.558 - b1 0.045 0.070 1.55 1.77 8 c 0.008 0.014 0.204 0.355 - d 0.980 1.060 24.89 26.9 5 d1 0.005 - 0.13 - 5 e 0.300 0.325 7.62 8.25 6 e1 0.240 0.280 6.10 7.11 5 e 0.100 bsc 2.54 bsc - e a 0.300 bsc 7.62 bsc 6 e b - 0.430 - 10.92 7 l 0.115 0.150 2.93 3.81 4 n20 209 rev. 0 12/93
16 ICL3225, icl3245 shrink small outline plastic packages (ssop) 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. in- terlead 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 dimen- sions are not necessarily exact. index area e d n 123 -b- 0.25(0.010) c a m b s e -a- b m -c- a1 a seating plane 0.10(0.004) c h 0.25(0.010) b m m l 0.25 0.010 gauge plane a2 m20.209 (jedec mo-150-ae issue b) 20 lead shrink small outline plastic package symbol inches millimeters notes min max min max a 0.068 0.078 1.73 1.99 a1 0.002 0.008? 0.05 0.21 a2 0.066 0.070? 1.68 1.78 b 0.010? 0.015 0.25 0.38 9 c 0.004 0.008 0.09 0.20? d 0.278 0.289 7.07 7.33 3 e 0.205 0.212 5.20? 5.38 4 e 0.026 bsc 0.65 bsc h 0.301 0.311 7.65 7.90? l 0.025 0.037 0.63 0.95 6 n20 207 0 deg. 8 deg. 0 deg. 8 deg. rev. 3 11/02
17 ICL3225, icl3245 thin shrink small outlin e plastic packages (tssop) index area e1 d n 123 -b- 0.10(0.004) c a m bs e -a- b m -c- a1 a seating plane 0.10(0.004) c e 0.25(0.010) b m m l 0.25 0.010 gauge plane a2 notes: 1. these package dimensions are wi thin allowable dimensions of jedec mo-153-ae, issue e. 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 0.15mm (0.006 inch) per side. 4. dimension ?e1? does not include in terlead flash or protrusions. inter- lead flash and protrusions shall not exceed 0.15mm (0.006 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 dam bar protrusion. allowable dambar protrusion shall be 0.08mm (0.003 inch) total in excess of ?b? dimen- sion at maximum material conditi on. minimum space between protru- sion and adjacent lead is 0.07mm (0.0027 inch). 10. controlling dimension: millimete r. converted inch dimensions are not necessarily exact. (angles in degrees) 0.05(0.002) m28.173 28 lead thin shrink small outline plastic package symbol inches millimeters notes min max min max a - 0.047 - 1.20 - a1 0.002 0.006 0.05 0.15 - a2 0.031 0.051 0.80 1.05 - b 0.0075 0.0118 0.19 0.30 9 c 0.0035 0.0079 0.09 0.20 - d 0.378 0.386 9.60 9.80 3 e1 0.169 0.177 4.30 4.50 4 e 0.026 bsc 0.65 bsc - e 0.246 0.256 6.25 6.50 - l 0.0177 0.0295 0.45 0.75 6 n28 287 0 o 8 o 0 o 8 o - rev. 0 6/98
18 all intersil u.s. products are manufactured, asse mbled and tested utilizing iso9000 quality systems. intersil corporation?s quality ce rtifications 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, soft ware and/or specifications at any time without notice. accordingly, the reader is cautioned to verify that da ta sheets are current before placing orders. information furnishe d 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 paten ts 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 subsidiari es. for information regarding intersil corporation and its products, see www.intersil.com ICL3225, icl3245 shrink small outline plastic packages (ssop) notes: 1. symbols are defined in the ?mo seri es 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 mo ld 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 inte rlead flash or protrusions. inter- lead 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 in- dex 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 dam bar protrusion. allowable dam- bar protrusion shall be 0.13mm (0.005 inch) total in excess of ?b? dimension at maximum material condition. 10. controlling dimension: millimete r. converted inch dimensions are not necessarily exact. index area e d n 123 -b- 0.25(0.010) c a m bs e -a- l b m -c- a1 a seating plane 0.10(0.004) c h 0.25(0.010) b m m 0.25 0.010 gauge plane a2 m28.209 (jedec mo-150-ah issue b) 28 lead shrink small outline plastic package symbol inches millimeters notes min max min max a - 0.078 - 2.00 - a1 0.002 - 0.05 - - a2 0.065 0.072 1.65 1.85 - b 0.009 0.014 0.22 0.38 9 c 0.004 0.009 0.09 0.25 - d 0.390 0.413 9.90 10.50 3 e 0.197 0.220 5.00 5.60 4 e 0.026 bsc 0.65 bsc - h 0.292 0.322 7.40 8.20 - l 0.022 0.037 0.55 0.95 6 n28 287 0 o 8 o 0 o 8 o - rev. 1 3/95

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