19-4585; Rev 0; 4/09 ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver The MAX13223E is a +3.0V to +5.5V-powered EIA/TIA232 and V.28 communications interface with fault protection on the RS-232 line interface. This allows shorts of the transmitter outputs and receiver inputs to voltages in the ±70V range without adversely affecting the MAX13223E. The MAX13223E achieves 1µA supply current using Maxim’s AutoShutdown™ feature. The MAX13223E automatically enters a low-power shutdown mode when the RS-232 cable is disconnected or the receivers are inactive. The device turns on again when a valid transition at any receiver input is sensed. A proprietary, highefficiency, dual charge-pump power supply and a low-dropout transmitter combine to deliver true RS-232 performance from a single +3.0V to +5.5V supply. The MAX13223E has two receivers and two drivers and is guaranteed to run at data rates of 250kbps for one transmitter switching while maintaining RS-232 output levels. The MAX13223E operates from input voltages ranging from +3.0V to +5.5V and is available in a 20-pin, 6.5mm x 4.4mm, TSSOP package. The MAX13223E is specified over the -40°C to +85°C temperature range. Features o ±70V Fault Protection o +3.0V to +5.5V Supply Voltage o Overvoltage Current Limiting o Current Protection at Transmitter Outputs o AutoShutdown o 250kbps (Max) Data Rate o Low Current Consumption in Shutdown 1µA (typ) o Thermal Shutdown Protection o ±8kV IEC 61000-4-2 Contact-Discharge Method o -40°C to +85°C Operating Temperature Range Ordering Information PART TEMP RANGE PIN-PACKAGE MAX13223EEUP+ -40°C to +85°C 20 TSSOP +Denotes a lead(Pb)-free/RoHS-compliant package. Typical Operating Circuit Applications Automotive VCC Telematics Equipment CBYPASS 0.1µF Base Stations Utility Meters Industrial Equipment C1+ VCC V+ C3 C1 C1- Telecomm Equipment V- C2+ POS Terminal Equipment MAX13223E C2 C4 C2- TTL/CMOS INPUTS T1IN T1OUT T2IN T2OUT R1OUT AutoShutdown is a trademark of Maxim Integrated Products, Inc. RS-232 OUTPUTS R1IN 5kΩ TTL/CMOS OUTPUTS RS-232 INPUTS R2IN R2OUT 5kΩ Typical Operating Circuit appears at end of data sheet. EN FORCEON INVALID GND FORCEOFF TO POWERMANAGEMENT UNIT VCC ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX13223E General Description MAX13223E ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver ABSOLUTE MAXIMUM RATINGS (Voltages referenced to GND.) VCC ...................................................................... -0.3V to +7.0V V+ ..........................................................................-0.3V to +7.0V V- ...........................................................................+0.3V to -7.0V V+ to V- ................................................................................+13V Input Voltages T1IN, T2IN, EN, FORCEON, FORCEOFF ..........-0.3V to +6.0V R1IN, R2IN .......................................................................±70V Output Voltages T1OUT, T2OUT ................................................................±70V R1OUT, R2OUT, INVALID ......................-0.3V to (VCC + 0.3V) Short-Circuit Duration T1OUT, T2OUT.......................................................Continuous Continuous Power Dissipation (TA = +70°C) 20-Pin TSSOP (derate 13.6mW/°C above +70°C) .....1084mW Junction-to-Case Thermal Resistance (θJC) (Note 1) 20-Pin TSSOP...............................................................20°C/W Junction-to-Ambient Thermal Resistance (θJA) (Note 1) 20-Pin TSSOP............................................................73.8°C/W Operating Temperature Range .......................... -40°C to +85°C Junction Temperature ..................................................... +150°C Storage Temperature Range ............................ -65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. 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 = +3.0V to +5.5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25°C, unless otherwise noted. For VCC = +3.0V to +3.6V, C1–C3 = 0.1µF, C4 = 1µF. For VCC = +4.5V to +5.5V, C1 = 47nF, C2–C3 = 330nF, C4 = 1µF.) (Note 2) PARAMETER Supply Voltage SYMBOL Supply Current Supply Current AutoShutdown Supply Current Shutdown CONDITIONS VCC IASD ISD MIN TYP 3.0 MAX UNITS 5.5 V AutoShutdown disabled (FORCEON = FORCEOFF = VCC), no load 8 15 mA FORCEON = GND, FORCEOFF = VCC, R1IN and R2IN idle, T1IN and T2IN idle 1.0 10 µA FORCEOFF = GND 1.0 10 µA 0.8 V LOGIC INPUTS Input-Logic Low VT_IN,LO T_IN, EN, FORCEON, FORCEOFF, VCC = +3.3V to +3.6V, +5.0V to +5.5V Input-Logic High VT_IN,HI T_IN, FORCEON, FORCEOFF, EN Transmitter Input Hysteresis Input Leakage Current VCC = +3.3V 2.0 VCC = +5.0V 2.4 VTX,INHYS IIN,LKG V 0.5 T_IN, EN, FORCEON, FORCEOFF V ±0.01 ±1 µA ±0.05 ±10 µA 0.4 V RECEIVER OUTPUTS Output Leakage Current IRX,OUT,LKG EN = VCC Output-Voltage Low VRX,OUT,LO IOUT = 1.6mA Output-Voltage High VCC 0.6 VRX,OUT,HI IOUT = -1.0mA VCC 0.2 V INVALID OUTPUT (AutoShutdown (FORCEON = GND, FORCEOFF = VCC)) Receiver-Input Level to INVALID Output High 2 VRX_IN, INV_HI Figure 6a Positive level 2.7 Negative level _______________________________________________________________________________________ -2.7 V ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver (VCC = +3.0V to +5.5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25°C, unless otherwise noted. For VCC = +3.0V to +3.6V, C1–C3 = 0.1µF, C4 = 1µF. For VCC = +4.5V to +5.5V, C1 = 47nF, C2–C3 = 330nF, C4 = 1µF.) (Note 2) PARAMETER Receiver-Input Level to INVALID Output Low INVALID Output-Voltage Low INVALID Output-Voltage High SYMBOL VRX_IN, INV_LO CONDITIONS Figure 6a MIN TYP -0.3 VRX,INV_LO IOUT = 1.6mA VRX,INV_HI IOUT = -1.0mA MAX UNITS +0.3 V 0.4 V VCC 0.6 V RECEIVER INPUTS Input-Voltage Range Overvoltage Threshold VRX,IN Input Threshold Low VRX,LO Input Threshold High VRX,HI Input Resistance (Note 3) |VRX,OVTHR| RRX,INRES -70 24 28.3 +70 V 32 V VCC = +3.3V 0.6 VCC = +5.0V 0.8 VCC = +3.3V 2.4 VCC = +5.0V 2.4 V V -24V < VR_IN < +24V (Note 3) 3 VCC = V+ = V- = 0 35 5 250 7 +32V < |VR_IN| < +70V 35 250 RL = 3kΩ, Figure 4 ±5 VCC = V+ = V- = 0, TOUT = ±2V 300 kΩ TRANSMITTER OUTPUTS Output-Voltage Swing Output Resistance VO RTX,ROUT Overvoltage Protection Threshold |VTX,FB| Output Short-Circuit Current ITX,SHORT Overvoltage Current ITX,IFBOUT Output Leakage Current in Shutdown Mode T_OUT = 0 VOUT > VTX,FB VOUT < -VTX,FB V Ω 14 19 V ±80 mA 6 -6 T_OUT = +12V ITX,LKG ±6 450 T_OUT = -12V, VCC = 0 or 3V to 5.5V in shutdown mode -150 R1IN, R2IN, T1OUT, T2OUT -70 mA 900 µA -80 PROTECTION Overvoltage Protection Range +70 V ESD PROTECTION (Note 4) R1IN, R2IN, T1OUT, T2OUT All Other Pins IEC 6100-4-2 Contact Discharge ±8 Human Body Model ±8 Human Body Model ±2 kV _______________________________________________________________________________________ 3 MAX13223E ELECTRICAL CHARACTERISTICS (continued) MAX13223E ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver TIMING CHARACTERISTICS (VCC = +3.0V to +5.5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25°C, unless otherwise noted. For VCC = +3.0V to +3.6V, C1–C3 = 0.1µF, C4 = 1µF. For VCC = +4.5V to +5.5V, C1 = 47nF, C2–C3 = 330nF, C4 = 1µF.) (Note 2) PARAMETER Maximum Data Rate SYMBOL DR CONDITIONS RL = 3kΩ, CL = 1000pF, one transmitter switching, Figure 1 MIN TYP MAX 250 UNITS kbps Receiver Positive or Negative Threshold to INVALID High tINVH VCC = 5V, Figure 6b 1 µs Receiver Positive or Negative Threshold to INVALID Low tINVL VCC = 5V, Figure 6b 30 µs Receiver Edge to Transmitters Enabled tWU VCC = 5V, Figure 6b 135 µs Receiver-Output Enable Time tRX,EN Normal operation 200 ns Receiver-Output Disable Time tRX,DIS Normal operation 200 ns 50 ns (Note 5) 200 ns Receiver Skew |tPRHL - tPRLH| Transmitter Skew |tPTHL - tPTLH| Receiver Propagation Delay Transmitter Propagation Delay tPRHL tPRLH tPTHL tPTLH 0.3 CL = 150pF, Figure 4 µs 0.3 0.8 CL = 1nF, RL = 3kΩ, Figure 3 µs 0.6 Transmitter Fall Time or Rise Time tR, tF Figure 3 0.3 µs Transmitter Time to Exit Shutdown tSHDN Figure 7 100 µs Output Recovery Time tTX,REC CL = 1nF, RL = 5kΩ (Note 6) 100 µs SROUT VCC = 3.3V, RL = 3kΩ to 7kΩ, TA = +25°C, measured from +3V to -3V or -3V to +3V, one transmitter switching, CL = 1nF Transition-Region Slew Rate 6 30 V/µs Note 2: All devices are 100% production tested at TA = +85°C. Specifications are over -40°C to +85°C and are guaranteed by design. Note 3: Both receivers will operate over the ±70V input range. The input resistance increases with input voltage. The input resistance will increase within 24V ≤ |VR_IN| ≤ 32V. Note 4: Guaranteed by design, not production tested. Note 5: Transmitter skew is measured at the transmitter zero crosspoints. Note 6: Output recovery time is the delayed time for the transmitter to enter normal operating mode after an overvoltage condition. 4 _______________________________________________________________________________________ ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver T_IN T_OUT T_IN CL VO T_OUT R_IN 15pF RL Figure 1. Driver Test Circuit Figure 2. Receiver Test Circuit Timing Diagrams VCC VCC/2 T_IN 0 VCC/2 tPTHL tPTLH V0 3V 3V 0 0 T_OUT -3V -3V -V0 tF tR Figure 3. Driver Propagation Delay VIH R_IN tR, tF ≤ 10ns 1.3V 1.7V VIL tPRHL tPRLH V0H VCC/2 R_OUT VCC/2 V0L Figure 4. Receiver Propagation Delay _______________________________________________________________________________________ 5 MAX13223E Test Circuits Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) VOUT+ 4 20 18 + SLEW SLEW RATE (V/µs) 16 2 0 -2 14 - SLEW 12 10 8 6 -4 VOUT- -8 1000 2000 3000 40 4000 30 20 20kbps 15 10 5 0 0 5000 120kbps 25 2 0 LOAD CAPACITANCE (pF) 250kbps 35 4 -6 0 45 SUPPLY CURRENT (mA) 6 MAX13223E toc02 22 MAX13223E toc01 8 OPERATING SUPPLY CURRENT vs. LOAD CAPACITANCE SLEW RATE vs. LOAD CAPACITANCE 1000 2000 3000 4000 5000 T1 TRANSMITTING AT 250kbps T2 TRANSMITTING AT 15.6kbps 0 1000 2000 MAX13223E toc04 FORCEON = FORCEOFF T2OUT 5V/div 2V/div T1OUT VCC = +3.3V C1–C4 = 0.1µF 3000 4000 LOAD CAPACITANCE (pF) LOAD CAPACITANCE (pF) TRANSMITTER TIME TO EXIT SHUTDOWN 40µs/div 6 MAX13223E toc03 TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE TRANSMITTER OUTPUT VOLTAGE (V) MAX13223E ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver _______________________________________________________________________________________ 5000 ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver PIN NAME FUNCTION Receiver Enable Control Input. Drive EN low for normal operation. Drive EN high to force the receiver outputs (R1OUT, R2OUT) into a high-impedance state. Positive Terminal of the Voltage Doubler Charge-Pump Capacitor 1 EN 2 C1+ 3 V+ +5.5V Generated by Charge Pump 4 C1- Negative Terminal of the Voltage Doubler Charge-Pump Capacitor 5 C2+ Positive Terminal of Inverting Charge-Pump Capacitor 6 C2- Negative Terminal of Inverting Charge-Pump Capacitor 7 V- 8 T2OUT -5.5V Generated by Charge Pump RS-232 Transmitter 2 Output 9 R2IN 10 R2OUT RS-232 Receiver 2 Input Receiver 2 Logic Output 11 INVALID Valid Signal Detector Output. INVALID is high if a valid RS-232 level is present on any receiver input. 12 T2IN Transmitter 2 Logic Input 13 T1IN Transmitter 1 Logic Input 14 FORCEON 15 R1OUT Receiver 1 Logic Output 16 R1IN RS-232 Receiver 1 Input 17 T1OUT 18 GND 19 VCC 20 FORCEOFF Active-High FORCEON Input. Drive FORCEON high to override AutoShutdown, keeping transmitters and charge pump on (FORCEOFF must be high). RS-232 Transmitter 1 Output Ground +3.0V to +5.5V Supply Voltage. Bypass VCC with a 0.1µF ceramic capacitor located as close to the device as possible. Active-Low FORCEOFF Input. Drive FORCEOFF low to shut down transmitters, receivers, and on-board charge pumps, overriding AutoShutdown and FORCEON. Detailed Description Figure 2 shows the receiver test circuit. Figure 3 shows driver propagation delay and Figure 4 shows receiver propagation delay. Dual Charge-Pump Voltage Converter The MAX13223E internal power supply consists of a dual-mode regulated charge pump that provides output voltages of +5.5V (doubling charge pump) and -5.5V (inverting charge pump), regardless of the input voltage (VCC) over the +3.0V to +5.5V range. The charge pumps operate in a discontinuous mode. If the output voltages are less than 5.5V, the charge pumps are enabled. If the output voltages exceed 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. RS-232 Transmitters The transmitters are inverting level translators that convert logic levels to EIA/TIA-232/V.28 levels. They guarantee a 250kbps data rate with worst-case loads of 3kΩ in parallel with 1000pF, providing compatibility with PC-to-PC communication software. The MAX13223E can operate at data rates of 250kbps (max). Transmitters can be paralleled to drive multiple receivers. When FORCEOFF is driven to ground, or the AutoShutdown circuitry senses invalid voltage levels at all receiver inputs, the transmitters are disabled and the outputs are forced into a high-impedance state. Figure 5 shows a complete system connection. RS-232 Receivers The MAX13223E’s receivers convert RS-232 signals to logic output levels. Both receiver outputs can be tristated using the EN input. In shutdown (FORCEOFF = low) or in AutoShutdown, the MAX13223E’s receivers are active (Table 1). Driving EN high places the receivers’ outputs in a high-impedance state. _______________________________________________________________________________________ 7 MAX13223E Pin Description MAX13223E ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver a) FORCEOFF FORCEON TRANSMITTER ENABLED, INVALID HIGH INVALID +2.7V RECEIVER INPUT POWERMANAGEMENT UNIT OR CPU MAX13223E INDETERMINATE +0.3V 0 AutoShutdown, TRANSMITTER DISABLED, 1µA SUPPLY CURRENT -0.3V INDETERMINATE -2.7V TRANSMITTER ENABLED, INVALID HIGH UART RS-232 b) RECEIVER INPUT VOLTAGE (V) +2.7V +0.3V -0.3V INVALID REGION -2.7V VCC INVALID OUTPUT (V) Figure 5. Interface Under Control of PMU 0 Table 1. Receiver Control Truth Table EN R_OUT 0 Active 1 High Impedence tINVL tINVH V+ tWU VCC 0 V- AutoShutdown The MAX13223E achieves 1µA supply current with Maxim’s AutoShutdown feature, which operates when FORCEON is low and FORCEOFF is high. When the device senses no valid signal levels on both receiver inputs for > 30µs (typ), the onboard charge pump and drivers are shut off, reducing supply current to 1µA. This occurs if the RS-232 cable is disconnected or the connected peripheral transmitters are turned off. The device turns on again when a valid level is applied to either RS-232 receiver input. As a result, the system saves power. Table 2 summarizes the MAX13223E’s operating modes. FORCEON and FORCEOFF override 8 Figures 6a and 6b. Trip Levels for Entering and Exiting AutoShutdown AutoShutdown. When neither control is asserted, the IC selects between these states automatically, based on receiver input levels. Figure 6a shows the input levels and Figure 6b shows the timing diagram for AutoShutdown operation. Software-Controlled Shutdown If direct software control is desired, INVALID can be used to indicate a DTR or Ring indicator signal. Connect FORCEOFF and FORCEON together to bypass AutoShutdown; therefore, the line acts as a SHDN input. _______________________________________________________________________________________ ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver MAX13223E Table 2. AutoShutdown Control INPUTS OUTPUTS INVALID OUTPUT OPERATION MODE T_OUT 0 Shutdown (Forced Off) High-Z FORCEOFF FORCEON VALID RECEIVER INPUT LEVEL 0 X No 0 X Yes 1 Shutdown (Forced Off) High-Z 1 0 No 0 Shutdown (AutoShutdown) High-Z 1 0 Yes 1 Active (AutoShutdown) Active 1 1 No 0 Active (Forced On) Active 1 1 Yes 1 Active (Forced On) Active X = Don’t Care. Applications Information Capacitor Selection The capacitor type used for C1–C4 is not critical for proper operation; either polarized or nonpolarized capacitors may be used. The charge pump requires 0.1µF capacitors for 3.3V operation. For other supply voltages, see Table 3 for required capacitor values. Do not use values smaller than those listed in Table 3. Increasing the capacitor values (e.g., by a factor of 2) reduces ripple on the transmitter outputs and slightly reduces power consumption. C2, C3, and C4 can be increased without changing C1’s value. However, do not increase C1 without also increasing the values of C2, C3, and C4 to maintain the proper ratios (C1 to the other capacitors). When using the minimum required capacitor values, make sure the capacitor value does not degrade excessively with temperature. If in doubt, use capacitors with a larger nominal value. The capacitor’s equivalent series resistance (ESR) usually rises at low temperatures and influences the amount of ripple on V+ and V-. Table 3. Required Capacitor Values VCC (V) C1, CBYPASS (µF) C2, C3 (µF) C4 (µF) 3.0 to 3.6 0.1 0.1 1 4.5 to 5.5 0.047 0.33 1 Power-Supply Decoupling Transmitter Outputs when Exiting Shutdown Figure 7 shows two transmitter outputs when exiting shutdown mode. As they become active, the two transmitter outputs are shown going to opposite RS-232 levels. Each transmitter is loaded with 3kΩ in parallel with 2500pF. The transmitter outputs display no ringing or undesirable transients as they come out of shutdown. Note that the transmitters are enabled only when the magnitude of V- exceeds approximately 3V. FORCEON = FORCEOFF T2OUT 5V/div 2V/div T1OUT VCC = +3.3V C1–C4 = 0.1µF 40µs/div Figure 7. Transmitter Outputs when Exiting Shutdown or Powering Up In most circumstances, a 0.1µF VCC bypass capacitor is adequate. In applications that are sensitive to power-supply noise, decouple VCC to ground with a capacitor of the same value as the charge-pump capacitor C1. Connect bypass capacitors as close to the IC as possible. _______________________________________________________________________________________ 9 MAX13223E ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver Fault Protection The MAX13223E is designed to survive faults such as direct shorts to power supplies, miswiring faults, connector failures, and tool misapplications of the transmitter outputs and receiver inputs to voltages in the ±70V range without damage. This fault protection is applicable in all modes of the MAX13223E: active, shutdown, and powered down. Both receivers operate over the ±70V input range, but the termination resistor (RRX,I) increases when |V R_IN | voltage exceeds ±32V. A receiver’s input termination resistor reduces to its nominal value if the input voltage reduces to within the ±24V range. The receiver inputs and transmitter outputs are independently fault protected. RC 1MΩ CHARGE-CURRENT LIMIT RESISTOR HIGHVOLTAGE DC SOURCE Cs 100pF RD 1500Ω DISCHARGE RESISTANCE DEVICE UNDER TEST STORAGE CAPACITOR Figure 8a. Human Body ESD Test Model ±8kV ESD Protection As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against electrostatic discharges encountered during handling and assembly. In using the MAX13223E, C4 must be a 1µF capacitor for the extended ESD protection. The driver outputs and receiver inputs of the MAX13223E have extra protection against static electricity. Maxim’s engineers have developed state-of-the-art structures to protect these pins against ESD of ±8kV without damage. The ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down. After an ESD event, Maxim’s E versions keep working without latchup, whereas competing RS-232 products can latch and must be powered down to remove latchup. ESD protection can be tested in various ways. The transmitter outputs and receiver inputs of this product family are characterized for protection to the following limits: 1) ±8kV using the Human Body Model 2) ±8kV using the Contact-Discharge Method specified in IEC 61000-4-2 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 8a shows the Human Body Model and Figure 8b 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 test device through a 1.5kΩ resistor. 10 IP 100% 90% Ir PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE) AMPERES 36.8% 10% 0 0 tRL TIME tDL CURRENT WAVEFORM Figure 8b. Human Body Current Waveform IEC 61000-4-2 The IEC 61000-4-2 standard covers ESD testing and performance of finished equipment. It does not specifically refer to integrated circuits. The major difference between tests done using the Human Body Model and IEC 61000-4-2 is higher peak current in IEC 61000-4-2, because series resistance is lower in the IEC 61000-4-2 model. Hence, the ESD withstand voltage measured to IEC 61000-4-2 is generally lower than that measured using the Human Body Model. Figure 9a shows the IEC 61000-4-2 model and Figure 9b shows the current waveform for the ±8kV, IEC 61000-4-2, level 4, ESD Contact-Discharge Method. ______________________________________________________________________________________ ±70V Fault-Protected, 3.0V to 5.5V, 2Tx/2Rx RS-232 Transceiver DISCHARGE RESISTANCE CHARGE CURRENT LIMIT RESISTOR HIGHVOLTAGE DC SOURCE Pin Configuration RD 330Ω Cs 150pF STORAGE CAPACITOR TOP VIEW EN 1 DEVICE UNDER TEST 20 FORCEOFF C1+ 2 19 VCC V+ 3 18 GND C1- 4 17 T1OUT C2+ 5 16 R1IN MAX13223E C2- 6 Figure 9a. IEC 61000-4-2 ESD Test Model V- 7 T2OUT 8 13 T1IN R2IN 9 12 T2IN I 100% 15 R1OUT 14 FORCEON R2OUT 10 11 INVALID 90% I PEAK TSSOP Chip Information 10% t r = 0.7ns to 1ns PROCESS: CMOS t 30ns 60ns Figure 9b. IEC 61000-4-2 ESD Generator Current Waveform Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 20 TSSOP U20+2 21-0066 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11 © 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX13223E RC 50MΩ to 100MΩ