general description the max3314e is a ?v-powered eia/tia-232-compat-ible interface. it has one transmitter and one receiver in a flow-through architecture. the transmitter output and the receiver input are protected to ?5kv using iec 1000-4-2 air-gap discharge, ?kv using iec 1000-4-2 contact discharge, and ?5kv using the human body model. the transmitter has a low-dropout output stage provid- ing minimum rs-232-compatible ?.7v output levels while driving 3k and 1000pf at 460kbps. both +5v and -5v must be supplied externally. the max3314e has a shdn function that reduces sup- ply current to 1?. the transmitter is disabled and putinto tristate while the receiver remains active. the max3314e is available in 8-pin ?ax, sot23, and so packages. ________________________applications digital cameraspdas gps pos telecommunications handy-terminals set-top boxes features ? esd protection for rs-232 i/o pins ?5kv?uman body model?kv?ec 1000-4-2 contact discharge ?5kv?ec 1000-4-2 air-gap discharge ? 1? low-power shutdown with receiver active ? 30? operating supply current ? 460kbps guaranteed data rate ? 8-pin sot23 package ? ?.7v rs-232-compatible levels max3314e 15kv esd-protected, 460kbps, 1a, rs-232-compatible transceiver ________________________________________________________________ maxim integrated products 1 rin tout tin 12 8 7 gnd v- rout v cc sot23/ max/so top view 3 4 6 5 max3314e shdn pin configuration c bypass 0.1 f 27 18 56 43 shdn v- tout rin tin rout v cc gnd 5k +5v max3314e capacitors may be polarized or nonpolarized. 0.1 f -5v typical operating circuit 19-1696; rev 1; 3/01 ordering information part temp. range pin-package max3314ecka-t 0 c to +70 c 8 sot23-8 max3314ecua 0 c to +70 c 8 max max3314ecsa 0 c to +70 c 8 so MAX3314EEKA-t -40 c to +85 c 8 sot23-8 max3314eeua -40 c to +85 c 8 max max3314eesa -40 c to +85 c 8 so for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. downloaded from: http:///
max3314e 15kv esd-protected, 460kbps, 1a, rs-232-compatible transceiver 2 _______________________________________________________________________________________ absolute maximum ratings stresses beyond those listed under ?bsolute 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. v cc to gnd .............................................................-0.3v to +6v v- to gnd ...............................................................+0.3v to -6v input voltages tin, shdn to gnd ...............................................-0.3v to +6v rin to gnd ......................................................................?5v output voltages tout to gnd................................................................?3.2v rout .................................................?0.3v to (v cc + 0.3v) short-circuit duration tout to gnd .........................................................continuous continuous power dissipation 8-pin sot23 (derate 9.7mw/? above +70?)...........777mw 8-pin ?ax (derate 4.1mw/? above +70?) ............300mw 8-pin so (derate 5.88mw/? above +70?)...............471mw operating temperature ranges max3314ec_a ..................................................0? to +70? max3314ee_a................................................-40? to +85? junction temperature .....................................................+150? storage temperature range ............................-65? to +150? lead temperature (soldering, 10s) ................................+300? parameter symbol conditions min typ max units dc characteristics p osi ti ve s up p l y op er ati ng rang e v cc 4.75 5 5.25 v n egati ve s up p l y op er ating range v- -4.75 -5 -5.25 v positive supply current shdn = v cc , no load 30 100 a negative supply current shdn = v cc , no load 15 30 a shutdown supply current shdn = gnd 1 10 a logic inputs (tin, shdn ) input logic threshold low v il 0.8 v input logic threshold high v ih 2.4 v transmitter input hysteresis 0.5 v input leakage current 0.01 a receiver output output voltage low v ol i out = 1.6ma 0.4 v output voltage high v oh i out = -1.0ma v cc - 0.3 v cc - 0.1 v receiver input input threshold low v il 0.8 v input threshold high v ih 2.4 v input hysteresis 0.5 v input resistance 5 k transmitter output output voltage swing tr ansm i tter outp ut l oad ed w i th 3k to g r ound 3.7 v output resistance (note 1) v cc = v- = 0, transmitter output = 2v 300 output short-circuit current 60 ma output leakage current v out = 12v, transmitter disabled 25 a esd protection (transmitter output, receiver input) human body model 15 iec 1000-4-2 air-gap discharge 15 esd-protection voltage iec 1000-4-2 contact discharge 8 kv electrical characteristics (v cc = +5v, v- = -5v, t a = t min to t max . typical values are at t a = +25 c.) downloaded from: http:///
max3314e 15kv esd-protected, 460kbps, 1a, rs-232-compatible transceiver _______________________________________________________________________________________ 3 note 1: not tested, guaranteed by design. timing characteristics (v cc = +5v, v- = -5v, t a = t min to t max . typical values are at t a = +25 c.) parameter symbol conditions min typ max units maximum data rate r l = 3k , c l = 1000pf, transmitter switching 460 kbps t plh receiver input to receiver output,c l = 150pf 0.15 receiver propagation delay t phl receiver input to receiver output,c l = 150pf 0.15 ? transmitter skew 100 ns receiver skew 50 ns transition region slew rate r l = 3k to 7k , c l = 150pf to 1000pf, measured from +3v to -3v or -3v to +3v 8 v/? 0 21 54 3 87 6 9 0 1000 500 1500 2000 2500 3000 slew rate vs. load capacitance max3314e-01 load capacitance (pf) slew rate (v/s) +slew -slew -6 1 -1-2 2 3 54 6 0 1000 1500 2000 2500 3000 transmitter output voltage vs. load capacitance max3314e-02 load capacitance (pf) transmitter output voltage (v) 0 -3-4 -5 500 20kbps/120kbps 460kbps/250kbps 460kbps/250kbps 20kbps/120kbps 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 0 500 1000 1500 2000 2500 3000 supply current vs. load capacitance max3314e-03 load capacitance (pf) supply current (ma) 250kbps 120kbps 460kbps 20kbps typical operating characteristics (v cc = +5v, v- = -5v, 250kbps data rate, transmitter loaded with 3k and c l , t a = +25 c, unless otherwise noted.) downloaded from: http:///
max3314e 15kv esd-protected, 460kbps, 1a, rs-232-compatible transceiver 4 _______________________________________________________________________________________ detailed description rs-232-compatible drivers the transmitter is an inverting level translator that con-verts cmos-logic levels to ?.7v eia/tia-232-compati- ble levels. it guarantees data rates up to 460kbps with worst-case loads of 3k in parallel with 1000pf. when shdn is driven low, the transmitter is disabled and put into tristate. the transmitter input does not have a pull-up resistor. connect to ground if unused. rs-232-compatible receivers the max3314e s receiver converts rs-232 signals to cmos-logic output levels. the receiver is rated toreceive signals to ?5v. it will remain active during shutdown mode. max3314e shutdown mode in shutdown mode, the transmitter output is put into highimpedance (table 1). this reduces supply current to 1?. the time required to exit shutdown is less than 2.5?. applications information capacitor selection the capacitor type used is not critical for proper opera-tion; either polarized or nonpolarized capacitors are acceptable. if polarized capacitors are used, connect polarity as shown in the typical operating circuit . bypass v cc and v- to ground with at least 0.1?. transmitter outputs when exiting shutdown figure 1 shows the transmitter output when exitingshutdown mode. the transmitter is loaded with 3k in parallel with 1000pf. the transmitter output displays noringing or undesirable transients as the max3314e comes out of shutdown. high data rates the max3314e maintains minimum rs-232-compatible?.7v transmitter output voltage even at high data rates. figure 2 shows a transmitter loopback test circuit. figure 3 shows the loopback test result at 120kbps, and figure 4 shows the same test at 250kbps. 15kv esd protection as with all maxim devices, esd-protection structures areincorporated on all pins to protect against electrostatic discharges encountered during handling and assembly. the max3314e driver outputs and receiver inputs have extra protection against static discharge. maxim s engi- neers have developed state-of-the-art structures to pro-tect these pins against esd of ?5kv without damage. the esd structures withstand high esd in all states: nor- mal operation, shutdown, and powered down. after an esd event, maxim s e versions keep working without latchup, whereas competing products can latch andmust be powered down to remove latchup. esd protection can be tested in various ways. the trans- mitter outputs and receiver inputs of the product family are characterized for protection to the following limits: ?5kv using the human body model ?kv using the contact discharge method specifiedin iec 1000-4-2 ?5kv using the iec 1000-4-2 air-gap method pin description pin name function 1v cc +5v 5% external power supply. decouple with a 0.1 f capacitor to ground. 2 shdn shutdown, active low (0 = off, 1 = on). 3 rout ttl/cmos receiver output 4 tin ttl/cmos transmitter input 5 tout rs-232-compatible transmitter output 6 rin rs-232-compatible receiver input 7 v- -5v 5% external power supply. decouple with a 0.1 f capacitor to ground. 8 gnd ground downloaded from: http:///
esd test conditions esd performance depends on a variety of conditions.contact maxim for a reliability report that documents test setup, test methodology, and test results. human body model figure 5 shows the human body model, and figure 6shows the current waveform it generates when dis- charged into low impedance. this model consists of a 100pf capacitor charged to the esd voltage of interest, which is then discharged into the test device through a 1.5k resistor. max3314e 15kv esd-protected, 460kbps, 1a, rs-232-compatible transceiver _______________________________________________________________________________________ 5 table 1. shutdown logic truth table shdn transmitter output receiver output l high z active h active active figure 1. transmitter outputs when exiting shutdown orpowering up 1 s/div shdn tout 5v/div 0 1.5v/div 0 tin = gnd tin = v cc figure 2. loopback test circuit 0.1 f shdn tout rin tin rout v cc gnd 5k +5v max3314e 0.1 f -5v 1000pf v- figure 3. loopback test result at 120kbps 5 s/div tout tinrout figure 4. loopback test result at 250kbps 2 s/div tout tinrout downloaded from: http:///
max3314e iec 1000-4-2 the iec 1000-4-2 standard covers esd testing and per-formance of finished equipment; it does not specifically refer to ics. the max3314e helps design equipment that meets level 4 (the highest level) of iec 1000-4-2 without the need for additional esd-protection compo- nents. the major difference between tests done using the human body model and iec 1000-4-2 is higher peak current in iec 1000-4-2 because series resistance is lower in the iec 1000-4-2 model. hence, the esd with- stand voltage measured to iec 1000-4-2 is generally lower than that measured using the human body model. figure 7 shows the iec 1000-4-2 model, and figure 8 shows the current waveform for the 8kv, iec 1000-4-2, level 4, esd contact discharge test. the air-gap test involves approaching the device with a charged probe. the contact discharge method connects the probe to the device before the probe is energized. machine model the machine model for esd tests all pins using a200pf storage capacitor and zero discharge resis- tance. its objective is to emulate the stress caused by contact that occurs with handling and assembly duringmanufacturing. of course, all pins require this protec- tion during manufacturing, not just rs-232 inputs and outputs. therefore, after pc board assembly, the machine model is less relevant to i/o ports. chip information transistor count: 128 15kv esd-protected, 460kbps, 1a, rs-232-compatible transceiver 6 _______________________________________________________________________________________ charge-current limit resistor discharge resistance storagecapacitor c s 100pf r c 1m r d 1500 high- voltage dc source device under test figure 6. human body current waveform i p 100% 90% 36.8% t rl time t dl current waveform peak-to-peak ringing(not drawn to scale) i r 10% 0 0 amperes figure 7. iec 1000-4-2 esd test model charge-current limit resistor discharge resistance storagecapacitor c s 150pf r c 50m to 100m r d 330 high- voltage dc source device under test figure 8. iec 1000-4-2 esd generator current waveform t r = 0.7ns to 1ns 30ns 60ns t 100% 90%10% i peak i figure 5. human body esd test model downloaded from: http:///
max3314e 15kv esd-protected, 460kbps, 1a, rs-232-compatible transceiver _______________________________________________________________________________________ 7 package information 8lumaxd.eps sot23, 8l.eps downloaded from: http:///
max3314e 15kv esd-protected, 460kbps, 1a, rs-232-compatible transceiver 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. 8 _____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 2001 maxim integrated products printed usa is a registered trademark of maxim integrated products. package information (continued) soicn.eps downloaded from: http:///
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