19-1076; Rev 0; 9/96 MAKiLM +15kV ESD-Protected, EMC-Compliant, 230kbps RS-232 Serial Port for Motherboards/Desktop PCs General Description The MAX3185 is a complete OTE RS-232 serial port designed to meet the stringent ESD requirements of the European community. All transmitter outputs and receiv- er inputs are protected to +15kV using IEC 1000-4-2 Air-Gap Discharge, +8kV using IEC 1000-4-2 Contact Discharge, and +15kV using the Human Body Model. The MAX3185 has three RS-232 transmitters, five RS- 232 receivers, and no charge pump, optimizing it for operation in desktop PC and motherboard applications. It is guaranteed to run at data rates up to 230kbps, pro- viding compatibility with popular software for communi- cating with personal computers. Power-supply current is less than 300UA for Ipp and Iss, and less than imA for icc. The MAX3185 is pin and functionally compatible with the industry-standard 75185, so existing designs can instantly become EMC compliant. The MAX3185 is available in an SO package and in the tiny SSOP that further reduces board space. Features @ Enhanced ESD Protection: +15kVHuman Body Model +8kVIEC1000-4-2, Contact Discharge +15kV-IEC1000-4-2, Air-Gap Discharge Latchup Free During an ESD Event 20-Pin SSOP and SO Packages Guaranteed 230kbps Data Rate Flow-Through Pinout Pin Compatible with SN75C185 Complete DTE Serial Port rf @ Ordering Information PART TEMP. RANGE PIN-PACKAGE 2 MAX3185CWP OC to +70C 20 SO Applicat PP lications MAX3185CAP OC to +70C 20 SSOP Desktop PC MAX3185EWP -40C to +85C 20 SO Motherboards MAX3185EAP -40C to +85C 20 SSOP Instruments Equipment Meeting IEC 1000-4-2 Typical Operating Circuit Pin Configuration MAAXLAA MAXIAA MAX3185 TOP VIEW 4 nD RS-23 $282 TTLYCMOS Logic vO TTLICMOS Logic vo INTERCONNECTING CABLE 2 Teh mm 2 yp mw 2 A A 2 &/ \8/ \8/ VY Vec RiOUT R20UT R30UT THIN T2IN R4QUT T3IN R5QUT MAAXLAA TH) ono MAX3185 SO/SSOP Vpo RUIN R2iN R3IN TIOUT TOUT RAIN T30UT RSIN Vss MAAXLAA For free samples & the latest literature: http:/Awww.maxim-ic.com, or phone 1-800-998-8800 S8LEXVIN Maxim Integrated Products 2-107MAX3185 +15kV ESD-Protected, EMC-Compliant, 230kbps RS-232 Serial Port for Motherboards/Desktop PCs ABSOLUTE MAXIMUM RATINGS -0.3V to +7V Continuous Power Dissipation (Ta = +70C) .-0.3V to +14V Wide SO (derate 10.00mW/C above +70C).............. 800mWw +0.3V to -14V SSOP (derate 8.0OmW/C above +70C) oo... 640mWw Operating Temperature Ranges Leeceeeeenenee eee tccanes eects eeeneriepecsnsaseendanestigeceseeaseeees MAX3185C_ Poo, OCS to +70C bocce uence eetetecesecegnestecesenpeensesaatitiitesusettnasiteriseeateeasees MAX3185E_P.......... -40C to +85C Storage Temperature Range .......... 65C to +160C Lead Temperature (soldering, 108C) .......0.c ee +300C Short-Circuit Duration Tout (one at a time) Continuous Rou (one at a time) a Continuous 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 = +4.5V to +5.5V, Voo = +10.8V to +13.2V, Vsg = -10.8V to -13.2V, Ta = TMIN to Tmax, Unless otherwise noted. Typical values are at Ta = +25C.) PARAMETER SYMBOL | CONDITIONS MIN TYP MAX | UNITS DC CHARACTERISTICS Voc 45 5.5 Operating Voltage Range Vob 10.8 13.2 Vv Vss -13.2 -10.8 Icc No load 380 1500 Supply Current lop No load 185 500 LA iss No load 185 500 LOGIC Input Logic Threshoid Low VILT TiN 0.8 Vv Input Logic Threshold High VIHT TIN 2.0 Vv Input Leakage Current 0.01 1 pA Output Voltage Low VOLR Rout; ISINK = 3.2mA 0.4 Vv Output Voltage High VOHR Rout: Isquace = 1mA Voc - 0.6 Vv TRANSMITTER OUTPUTS / Vop = 7.0V, Vss = -7.0V, Re = 3kQ +5.0 Output Voltage Swing Vpp 2 12V. Ves = 1 2V, AL = ak 395 Vv Transmitter Output Resistance Voc = Vop = Vss = OV, VT_out = 2V 300 Q Ae 282 Output Short-Circuit 35 +60 mA RECEIVER INPUTS Receiver Input Voltage 25 25 Vv Operating Range RS-232 Input Threshold Low 0.75 Vv RS-232 Input Threshold High 2.4 v RS-232 Input Hysteresis 0.65 Vv RS-232 Input Resistance 3 5 7 kQ Receiver Output Short-Circuit +40 mA Current MA AXLAA 2-108+15kV ESD-Protected, EMC-Compliant, 230kbps RS-232 Serial Port for Motherboards/Desktop PCs ELECTRICAL CHARACTERISTICS (continued) (Vcc = +4.5V to +5.5V, Vop = +10.8V to +13.2V. Vss = -10.8V to -13.2V, Ta = TIN to TMax, unless otherwise noted. Typical values are at Ta = +25C.) PARAMETER | SYMBOL | CONDITIONS MIN TYP MAX | UNITS ESD CHARACTERISTICS Human Body Model +15 ESD Protection {EC 1000-4-2 (Contact Discharge) +8 kV IEC 1000-4-2 (Air-Gap Discharge) #15 TIMING CHARACTERISTICS Transmitter Output t Vopb = 12V, Vss = -12V, AL = 3kQ, 4 Propagation Delay, Low to High PLHT Cy = 1000pF, Ta = +25C HS Transmitter Output t Vop = 12V, Vssg = -12V, Ry = 3kQ, 4 Propagation Delay, High toLow | PALT | oy = 1000pF, Ta = +25C us Transmitter Propagation Delay ts Vop = 12V, Vss = -12V, RL = 3kQ, 04 Skew, | teLHt - teHtt | KT Cy = 1000pF, Ta = +25C , us Vop = 12V, Vss = -12V, Ci = 150pF to Ri = 3kQ to 7kQ, 2500pF 4 30 Transition Output Slew Rate SR measured from +3V to -3V Vus or -3V to +3V, Figure 3. CL = 50pF to 8 30 Ta = +25C 1O00pF Receiver Output _ _ 7 Propagation Delay, Low to High 'PLHR Vec = SV, CL = SOpF, Ta = +25C 4.0 ps Receiver Output _ _ _ Propagation Delay, High to Low tPHLR =| Voc = 5V, CL = SOpF. Ta = +25C 4.0 ps Receiver Propagation Delay t Voc = 5V, = 50pF, Ta = +25 4 Skew, | teLur - teuir | SKR cc = V, CL pF, Ta = +25C 0 Us Voc = 5V, Vop = 12V, Ci = SOPF to 120 Vsg = -12V, 2500pF Guaranteed Data Rate DR RL = 3kQ to 7kQ G2 S0nFt kbps = Sela | , L = SOpF to Ta= +25C 1000pF 230 Mouse Driveability T30UT = -5mA, TIOUT = T2OUT = +5mA t7.5 Vv 2-109 MAAXLIM SSLEXVINMAX3185 +15kV ESD-Protected, EMC-Compliant, 230kbps RS-232 Serial Port for Motherboards/Desktop PCs (Voc = +5.0V, Vop = +12.0V, Vss = -12.0V, Ta = +25C, unless otherwise noted.) SUPPLY CUREENT (mA} o 12.5 = 10.0 75 5,0 2.5 2.5 5.0 75 -10.0 TRANSMITTER OUTPUT VOLTAGE SUPPLY CURRENT SUPPLY CURRENT vs. SUPPLY VOLTAGE vs. LOAD CAPACITANCE fon. 240kbps [herent 5 ae 3 loo. fon, 120kbps 3 : = lop. 1 (pp. 20kbps 1 TRANSMITTER AT DATA RATE = = ot na a icg_| 2 TRANSMITTERS AT DATA RATE / 16 if + TRANSMITTER AT DATA RATE = a e 3 z Iss, 20kbps 3x0 + 25000F LOAD > 2 TRANSMITTERS AT DATA RATE / 1 = Igg, 120kbps & +0, LOAD % 240kbps Isg. 240kbps a ee 10.8 14.4 12.0 12.6 13.2 0 1000 2000 3000 4000 5000 SUPPLY VOLTAGE (V) LOAD CAPACITANCE (pF) TRANSMITTER OUTPUT VOLTAGE MAX3185 TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE vs. LOAD CURRENT PER TRANSMITTER 25 fos i ow g 20 = a Ss 1 TRANSMITTER AT DATA RATE = 2 2 TRANSMITTERS AT DATA RATE / 16 5 = 15 Skiz + C, LOAD - w 2 z Qo food = 10 i a Ee a 240kbps = 2 5 420kbps < 0 12.5 2-110 0 1000 2000 3000 4000 = 5000 0 2 4 6 8 10 12 14 16 18 LOAD CAPACITANCE (pF) LOAD CURRENT PER TRANSMITTER (mA) Typical Operating Characteristics SLEW RATE vs. LOAD CAPACITANCE FALL RISE 1 TRANSMITTER 240kbps 2 TRANSMITTERS 15kbos 3ks2 + Cy LOAD. 0 1000 2000 3000 4000 5000 LOAD CAPACITANCE (pF) SLEW RATE vs. TEMPERATURE a a FALL, SQO0pF ! : Ph RISE, 500p! RISE, 2000pF = FALL, 2000pF 5-35-19 5 25 45 65 85 105 125 TEMPERATURE (C) PAMXLMA+15kV ESD-Protected, EMC-Compliant, 230kbps RS-232 Serial Port for Motherboards/Desktop PCs Pin Description PIN NAME FUNCTION 1 Vop Supply-Voltage Input, +10.8V to +13.2V 12, 14, 17, 18, 19 RS50UT-R1OUT Receiver Outputs, swing between GND and Vcc 16, 15, 13 T3IN, T2iN, T1IN Transmitter Inputs 10 Vss Supply-Voltage Input, -10.8V to -13.2V 11 GND Ground. Connect system to ground. 2,3,4,7,9 RiINRSIN Receiver Inputs 5,6, 8 TIOUT, T2OUT, TZOUT | Transmitter Outputs, swing between Vpp and Vss 20 Vec Supply-Voltage Input, +4.5V to +5.5V Detailed Description Re SOM to 100M Ap 3300 215kV ESD Protection CHARGE-CURRENT DISCHARGE LIMIT RESISTOR RESISTANCE HIGH- VOLTAGE Cs STORAGE oc 150pF CAPACITOR SOURCE DEVICE UNDER >| TEST Figure 1a. 1EC1000-4-2 ESD Test Model | A 10% L..------}--------}------- 90% | \ A = i 10% } te = 0.7ns 10 TNS m tH, t g___. 6015. __-J Figure 1b. 1EC1000-4-2 ESD-Generator Current Waveform MAAKLIM As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against electro- static discharges encountered during handling and assembly. The MAX3185 driver outputs and receiver inputs have extra protection against static electricity found in normal operation. Maxim's engineers devel- oped state-of-the-art structures to protect these pins against ESD of +15kV, without damage. After an ESD event, the MAX3185 continues working without latchup. ESD protection can be tested in several ways. The transmitter outputs and the receiver inputs are charac- terized for protection to the following: 1) +15kV using the Human Body Model 2) +8kV using the Contact-Discharge Method specified in 1EC1000-4-2 (formerly IEC801-2) 3) +15kV using the Air-Gap Method specified in IEC 1000-4-2 (formerly IEC801-2) ESD Test Conditions ESD performance depends on a number of conditions. Contact Maxim for a reliability report that documents test setup, methodology, and results. SS8LEXVWN 2-111MAX3185 2-112 +15kV ESD-Protected, EMC-Compliant, 230kbps RS-232 Serial Port for Motherboards/Desktop PCs Human Body Model Figure 2a shows the Human Body Model, and Figure 2b shows the current waveform it generates when dis- charged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of inter- est, which is then discharged into the device through a 1.5kQ resistor. 1EC1000-4-2 The IEC 1000-4-2 standard covers ESD testing and per- formance of finished equipment: it does not specifically refer to integrated circuits. The MAX3185 helps you design equipment that meets Level 4 (the highest ievel) of 1EC1000-4-2, without additional ESD-protection com- ponents. The main difference between tests done using the Human Body Mode! and 1EC1000-4-2 is higher peak current in IEC1000-4-2. Because series resistance is lower in the IEC1000-4-2 ESD test model (Figure 1a), the ESD withstand voltage measured to this standard is generally lower than that measured using the Human Body Model. Figure 1b shows the current waveform for the +8kV 1EC1000-4-2 Level 4 ESD Contact-Discharge test. The Air-Gap test involves approaching the device with a charge probe. The Contact-Discharge method connects the probe to the device before the probe is energized. CHARGE-CURRENT DISCHARGE LIMIT RESISTOR RESISTANCE HIGH: pe) DEVICE VOLTAG Cg STORAGE UNDER pC 100pF CAPACITOR | TEST SOURCE Figure 2a. Human Body ESD Test Model Machine Model The Machine Model for ESD testing uses a 200pF stor- age capacitor and zero-discharge resistance. It mimics the stress caused by handling during manufacturing and assembly. Of course, all pins (not just RS-232 inputs and outputs) require this protection during man- ufacturing. Therefore, the Machine Model is less rele- vant to the I/O ports than are the Human Body Model and IEC 1000-4-2. Applications Information Use proper layout to ensure other devices on your board are not damaged in an ESD strike. Currents as high as 60A can instantaneously pass into ground, so be sure to minimize the ground-lead return path to the power supply. A separate return path to the power sup- ply is recommend. Trace widths should be greater than 40 mils. Bypass Vcc, Vop, and Vss with 0.1pF capaci- tors as close to the part as possible to ensure maxi- mum ESD protection. Tie any unused transmitter inputs to GND or Vcc. No external protection diodes are needed because the MAX3185 is not sensitive to power-supply sequencing. Ip 100% lr PEAK-TO-PEAK RINGING 90% {NOT DRAWN 10 SCALE) AMPERES 36.8% 10% F5 ee 0 0 te TIME t~ <+__ t to CURRENT WAVEFORM Figure 2b. Human Body Model Current Waveform MAAKLIM+15kV ESD-Protected, EMC-Compliant, 230kbps RS-232 Serial Port for Motherboards/Desktop PCs 3.0V DRIVER INPUT 1.54 ov TeHL TeLH Vou 34V 3.0V Vout ww ~3.0V. +3.3V te tae leaned _. pa |....2--_- VoL ft) : + SIGNAL GENERATOR QO RL T o Figure 3. Slew-Rate Test Circuit and Timing Diagram TRANSISTOR COUNT: 217 Chip Information MAAXLAA SS8SLEXVN 2-113