19-0199; Rev 1; 8/95 Programmable DTE/DCE, +5V RS-232 Transceiver _______________General Description ____________________________Features M The MAX214 +5V RS-232 transceiver provides a com- 'Eliminates Null Modem Cables A plete, 8-line, software-configurable, DTE or DCE port RS-232 interface. Tx, Rx, RTS, CTS, DTR, DSR, DCD, 'Programmable DTE or DCE Serial Port X and RI circuits can be configured as either Data '1µF Charge-Pump Capacitors 2 Terminal Equipment (DTE) or Data Circuit-Terminating 1 Equipment (DCE) using the DTE/DCE control pin. The '116kbps Data Rate—Guaranteed 4 MAX214 eliminates the need to swap cables when switching between DTE and DCE configurations. '20µA Shutdown Mode ________________________Applications 'Receivers Active in Shutdown AT-Compatible Laptop Computers ______________Ordering Information AT-Compatible Desktop Computers PART TEMP. RANGE PIN-PACKAGE Modems, Printers, and Other Peripherals MAX214CPI 0°C to +70°C 28 Plastic DIP MAX214CWI 0°C to +70°C 28 Wide SO __________Typical Operating Circuit MAX214C/D 0°C to +70°C Dice* MAX214EPI -40°C to +85°C 28 Plastic DIP +5V MAX214EWI -40°C to +85°C 28 Wide SO 1m F * Dice are specified at TA = +25°C. 16 27 C1+ VCC 15 1m F __________________Pin Configuration 1m F V+ 28 C1- 1m F 21 C2+ MAX214 V- 14 TOP VIEW C2- 1m F 5 TA DTE TRA 9 C2+ 1 28 C1- DCE 6 RA RTA 10 C2- 2 27 C1+ DTE HI-Z 3 26 SHDN 25 TB DTE TRB 20 N.C. 4 25 TB DCE 23 RB RTB 19 TA 5 MAX214 24 TC DTE RA 6 23 RB 24 TC DTE TRC 18 RDC 7 22 RC DCE 22 RC RTC 17 RE 8 21 DTE/DCE DCE DTE TRA 9 20 TRB DCE 7 RDC RDTC 11 RTA 10 19 RTB DTE DTE 8 RE RRE 12 RDTC 11 18 TRC RRE 12 17 RTC 21 DTE/DCE 26 GND 13 16 VCC SHDN 3 HI-Z V- 14 15 V+ GND 13 DIP/SO ________________________________________________________________Maxim Integrated Products 1 Call toll free 1-800-998-8800 for free samples or literature.

Programmable DTE/DCE, +5V RS-232 Transceiver 4 ABSOLUTE MAXIMUM RATINGS 1 VCC...........................................................................-0.3V to +6V Continuous Power Dissipation (TA= +70°C) 2 Input Voltages Plastic DIP (derate 9.09mW/°C above +70°C).............727mW X TIN, DTE/DCE, SHDN HI-Z......................-0.3V to (VCC+ 0.3V) Wide SO (derate 12.50mW/°C above +70°C)............1000mW RIN....................................................................................±15V Operating Temperature Ranges: A Output Voltages: MAX214C–I..............................................0°C to +70°C M TOUT..................................................................................±15V MAX214E–I..........................................-40°C to +85°C ROUT........................................................-0.3V to (VCC+ 0.3V) Storage Temperature Range......................-65°C to +150°C Short-Circuit (one output at a time) Lead Temperature (soldering, 10sec).......................+300°C TOUTto GND...........................................................Continuous ROUTto GND...........................................................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, C1 to C4 = 1m F, TA= TMIN to TMAX, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS RS-232 TRANSMITTERS Logic Input Threshold Low 0.8 1.4 V Logic Input Threshold High 1.4 2.0 V Normal operation 1 10 50 Logic Input Pull-Up Current m A Shutdown ±0.01 ±1 Output Voltage Swing All transmitter outputs loaded with 3kW to ground ±5.0 ±7.5 V Transmitter Output Resistance VCC= V+ = V- = 0V, VOUT= ±2V (Note 1) 300 300k W Output Short-Circuit Current VOUT= 0V ±7 ±25 mA RS-232 RECEIVERS Input Voltage Operating Range ±15 V Positive Threshold Input Low TA= +25°C, VCC= 5V, normal operation, SHDN = 0V 0.8 1.3 V Positive Threshold Input High TA= +25°C, VCC= 5V, normal operation, SHDN = 0V 1.8 2.4 V Positive Threshold Input VCC= 5V, normal operation, SHDN = 0V (no hysteresis 0.2 0.5 1.0 V Hysteresis in shutdown) Normal operation, SHDN = 0V -2.6 -1.9 Negative Threshold Input Low TA= +25°C, VCC= 5V V Shutdown, SHDN = 5V 0.8 1.3 Normal operation, SHDN = 0V -1.5 -0.2 Negative Threshold Input High TA= +25°C, VCC= 5V V Shutdown, SHDN = 5V 1.3 2.4 Negative Threshold Input VCC= 5V, normal operation, SHDN = 0V (no hysteresis 0.2 0.4 1.0 V Hysteresis in shutdown) Input Resistance HI-Z = 0V and SHDN = 0V 3 5 7 kW HI-Z = 5V or SHDN = 5V 100 300 TTL/CMOS Output Voltage Low IOUT= 3.2mA 0.2 0.4 V TTL/CMOS Output Voltage High IOUT= -1.0mA 3.5 VCC - 0.2 V 2 _______________________________________________________________________________________

Programmable DTE/DCE, +5V RS-232 Transceiver ELECTRICAL CHARACTERISTICS (continued) M (VCC= 4.5V to 5.5V, C1 to C4 = 1m F, TA= TMIN to TMAX, unless otherwise noted.) A PARAMETER CONDITIONS MIN TYP MAX UNITS X POWER SUPPLY 2 VCCSupply Current No load, TA= +25°C 9 20 mA 1 4 Shutdown Supply Current DTE/DCE = 0V, SHDN = TA= +25°C 4 20 m A HI-Z = VCC, Figure 1 TA= TMINto TMAX 50 CONTROL LOGIC(DTE/DCE, SHDN, HI-Z) Logic Input Threshold Low 0.8 1.3 V Logic Input Threshold High 1.3 2.0 V Input Leakage Current ±1 m A AC CHARACTERISTICS Normal operation, transmitters and receivers 200 116 Data Rate kbps Receivers in shutdown mode 20 TA = +25°C, VCC= 5V, RL= 3kW to 7kW , Transition-Region Slew Rate CL= to 2500pF, 6 12 30 V/m s measured from 3V to -3V or -3V to 3V Transmitter Propagation Delay, tPHLT 1.3 3.5 m s TTL to RS-232 (Normal Operation) tPLHT 1.4 3.5 Transmitter + to - Propagation-Delay Difference (Normal Operation) tPHLT- tPLHT 100 ns RReSc-2e3iv2e tro P TroTpLa (gNaotriomna Dl Oelpaeyr,ation) tPHLR, tPLHR 0.4 1.5 m s Receiver Propagation Delay, tPHLR 0.4 10 m s RS-232 to TTL (Shutdown Mode) tPLHR 1.5 10 Receiver Propagation-Delay Difference (Normal Operation) ‰ tPHLT- tPLHT‰ 100 ns MODE-CHANGE TIMING (DTE/DCE) Transmitter Enable Time tTEN(includes charge-pump start-up time) 250 m s Transmitter Disable Time tTTR 600 ns Transmitter DTE/DCE Switch Time tTSW 600 ns Receiver DTE/DCE Switch Time tRSW 300 ns Receiver Termination-Resistor (SHDN = 0V) 300 ns Connect/Disconnect Time Receiver Termination-Resistor Connect 250 m s Entering SHDN Time Receiver Termination-Resistor 300 ns Disconnect Exiting SHDN Time Note 1: The 300W minimum is the EIA/TIA-232E specification, but the actual resistance when in shutdown mode or when VCC= 0V is typically 300kW . _______________________________________________________________________________________ 3

Programmable DTE/DCE, +5V RS-232 Transceiver 4 __________________________________________Typical Operating Characteristics 1 (VCC= 5V, C1 to C4 = 1m F, all transmitters loaded with 3kW in parallel with 2.5nF, TA = +25°C, unless otherwise noted.) 2 X TRANSMITTER OUTPUT VOLTAGE (VOL) (cid:13) TRANSMITTER OUTPUT VOLTAGE (VOH)(cid:13) A vs. LOAD CAPACITANCE (cid:13) vs. LOAD CAPACITANCE(cid:13) TRANSMITTER OUTPUT VOLTAGE (VOH)(cid:13) M AT DIFFERENT DATA RATES AT DIFFERENT DATA RATES vs. VCC POSITIVE SUPPLY VOLTAGE --65..05 MAX214-01 77..46 20kbps MAX214-02 9.0 2 TRANSM1IT TTREARNSS LMOIATDTEERD LOADED MAX214-03 120kbps 8.5 7.2 3 TRANSMITTERS LOADED -6.5 64kbps 7.0 V (V)OL -7.0 64kbps V (V)OH 66..68 120kbps V (V)OH 78..50 -7.5 20kbps 6.4 -8.0 7.0 6.2 DATA RATE = 0kbps -8.5 6.0 6.5 0 1000 2000 3000 4000 5000 6000 7000 0 1000 2000 3000 4000 5000 6000 7000 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 LOAD CAPACITANCE (pF) LOAD CAPACITANCE (pF) VCC (V) TRANSMITTER OUTPUT VOLTAGE (VOL)(cid:13) TRANSMITTER OUTPUT VOLTAGES(cid:13) (cid:13) vs. POSITIVE SUPPLY VOLTAGE vs. V+, V- LOAD CURRENT SLEW RATE vs. LOAD CAPACITANCE --77..50 3 TRANSM2 ITTRTEARNSS MLOITATDEERDS LOADED MAX214-04 1680 MAX214-05 1280 S3 LTERWASN+L(cid:13)SEWM-IT(cid:13)TERS LOADED MAX214-06 1 TRANSMITTER LOADED 4 16 3 TRANSMITTERS LOADED V) V+ AND V-(cid:13) V- LOADED,(cid:13) V+ LOADED, s) V (V)OL--88..50 - T +, T(OUTOUT --4202 ELQOUAAADLLLELD YTR(cid:13)ANSMITTNEOORN SL OVUA+NDL(cid:13)OADED, N 0OOk NbLp OVsA-D(cid:13) mSLEW RATE (V/ 111024 S1 LTERWAN+(cid:13)SMITTER LOADED 8 -9.0 -6 SLEW-(cid:13) DATA RATE = 0kbps -8 6 1 TRANSMITTER LOADED -9.5 -10 4 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 0 20 40 60 80 0 2000 4000 6000 VCC (V) LOAD CURRENT (mA) LOAD CAPACITANCE (pF) 4 _______________________________________________________________________________________

Programmable DTE/DCE, +5V RS-232 Transceiver ______________________________________________________________Pin Description M A PIN NAME FUNCTION X 1, 2 C2+, C2- Terminals for negative charge-pump capacitor 2 3 HI-Z RS-232 receiver impedance control. Take high to disconnect the termination resistor. 1 4 N.C. No connect—not internally connected 4 5, 24, 25 TA, TC, TB TTL/CMOS driver A, C, B inputs 6, 8, 22, 23 RA, RE, RC, RB TTL/CMOS receiver A, E, C, B outputs TTL/CMOS DTE receiver output D for DTE/DCE = 0V, or TTL/CMOS DCE receiver output C for 7 RDC DTE/DCE = +5V 9, 18, 20 TRA, TRC, TRB RS-232 DTE driver output for DTE/DCE= 0V, or RS-232 DCE receiver input for DTE/DCE= +5V 10, 17, 19 RTA, RTC, RTB RS-232 DTE receiver input for DTE/DCE= 0V, or RS-232 DCE driver output for DTE/DCE= +5V RS-232 DTE receiver input D for DTE/DCE= 0V, or RS-232 DCE driver output C for 11 RDTC DTE/DCE= +5V 12 RRE RS-232 receiver input 13 GND Ground 14 V- -2VCCvoltage generated by the charge pump 15 V+ +2VCCvoltage generated by the charge pump 16 VCC +4.5V to +5.5V supply voltage Data terminal equipment (DTE) and data circuit-terminating equipment (DCE) control pin. 21 DTE/DCE DCE active high and DTE active low. 26 SHDN Shutdown control; shutdown high, normal operation low 27, 28 C1+, C1- Terminals for positive charge-pump capacitor _______________Detailed Description DTE/DCE Operation The DTE/DCE pin allows circuit configuration under The MAX214 RS-232 transceiver provides a complete, software control. Tables 1a and 1b show the pin defini- 8-line, software-configurable, DTE or DCE port RS-232 tions of the MAX214 in both DTE and DCE modes. The interface. Tx, Rx, RTS, CTS, DTR, DSR, DCD, and RI Function columns show the direction of data flow from circuits can be configured as either Data Terminal the input pin to the output pin of the MAX214, and onto Equipment (DTE) or Data Circuit-Terminating the corresponding DB-25 connector’s pin. Equipment (DCE) using the DTE/DCE control pin. The MAX214 eliminates the need to swap cables when +5V to ±10V Dual Charge-Pump switching between DTE and DCE configurations. This Voltage Converter is useful when, for example, a portable computer is The +5V to ±10V conversion is performed by two required to communicate with printers, modems, and charge-pump voltage converters (Figure 2). The first other computers without carrying multiple cables. uses capacitor C1 to double the +5V to +10V, storing the +10V on the output filter capacitor, C3. The second The MAX214 runs from a single +5V supply and incor- charge-pump voltage converter uses C2 to invert the porates a dual charge-pump voltage converter to gener- +10V to -10V, storing the -10V on the V- output filter ate the necessary voltages for the RS-232 transmitters. capacitor, C4. A shutdown mode is provided to save power when transmission is not required, but the receivers always In shutdown mode, V+ is pulled to VCC by an internal stay active for simple detection of ring indicator signals. resistor, and V- falls to GND. _______________________________________________________________________________________ 5

Programmable DTE/DCE, +5V RS-232 Transceiver 4 Table 1a. DTE-Operation Pin Configurations M 1 A 2 TTL/CMOS MAX214 MAX214 RS-232 DB-25 INPUT X I/O LABEL PIN FUNCTION PIN I/O LABEL PIN THRESHOLD X A 2 Transmitter (TxD) 5 9 TxD 2 1 M 4 Receiver (RxD) 6 10 RxD 3 + Request to Send (RTS) 25 20 RTS 4 Clear to Send (CTS) 23 19 CTS 5 - Data Terminal Ready (DTR) 24 18 DTR 20 Data Set Ready (DSR) 22 17 DSR 6 - Detector Carrier Data (DCD) 7 11 DCD 8 + + Ring Indicator (RI) 8 12 RI 22 Table 1b. DCE-Operation Pin Configurations MAX214 MAX214 RS-232 DB-25 INPUT FUNCTION PIN PIN I/O LABEL PIN THRESHOLD 5 10 RxD 3 6 9 TxD 2 + 25 19 CTS 5 23 20 RTS 4 - 17 DSR 6 24 11 DCD 8 22 18 DTR 20 - 7 8 12 RI 22 + 6 _______________________________________________________________________________________

Programmable DTE/DCE, +5V RS-232 Transceiver RS-232 Drivers M With VCC= 5V, the typical driver output voltage swing ISHDN is ±8V when loaded with a nominal 5kΩ RS-232 A +5.5V receiver. Under worst-case operating conditions X 1µF 1µF (including 116kbps data rate, 3kΩ ŒŒ 2500pF load, 2 VCC = 4.5V, maximum rated temperature) the output C1+(cid:13) VCC V+ swing is guaranteed to meet the ±5V minimum speci- 1 1µF C1-(cid:13) 1µF fvieodlta bgye EswIAin/TgI Ara-2n3g2e sa nfrdo mV .(2V8+. - T0h.6eV o)p toe nV--c.ircuit output 4 MAX214 V- C2+(cid:13) +5V Input thresholds are both CMOS and TTL compatible. 1µF The inputs of unused drivers can be left unconnected C2- 400k because 400kΩ pull-up resistors to VCC are included on-chip. Since all drivers invert, the pull-up resistors Tx +5.5V TIN TOUT force the outputs of unused drivers low. The input pull-up resistors typically source 10µA; in shutdown 3k mode, they are disconnected to reduce supply current. ROUT Rx RIN +5.5V When in low-power shutdown mode, the driver outputs 0V OR +5.5V(cid:13) are turned off and their leakage current is less than DRIVE DTE/DCE 5k 1µA, even if the transmitter output is back-driven with +5.5V HI-Z voltages up to ±15V. +5.5V SHDN GND RS-232 Receivers CAPACITORS MAY BE (cid:13) The receivers convert the RS-232 signals to POLARIZED OR UNPOLARIZED CMOS-logic levels. They invert, to match the inversion of RS-232 drivers. The guaranteed receiver input thresholds are significantly tighter than the ±3V Figure 1. MAX214 Shutdown-Current Test Circuit thresholds required by the EIA/TIA-232E specification, V+ S1 C1+ S2 S5 C2+ S6 VCC GND C1 C3 C2 IL + RL + C4 IL - RL - S3 S4 S7 S8 GND VCC V - C1- C2- 120kHz Figure 2. Charge-Pump Diagram _______________________________________________________________________________________ 7

Programmable DTE/DCE, +5V RS-232 Transceiver 4 Table 2. Control Pin Configurations 1 2 CONTROL INPUTS RS-232 PINS X SHUTDOWN HI-Z DTE/DCE TRA, TRB, TRC RTA, RTB, RTC, RDTC RRE A 0 0 0 Transmit Mode Receive Mode/5kW Receive Mode/5kW M 0 0 1 Receive Mode/5kW Transmit Mode Receive Mode/5kW 0 1 0 Transmit Mode Receive Mode/HI-Z Receive Mode/HI-Z 0 1 1 Receive Mode/HI-Z Transmit Mode Receive Mode/HI-Z 1 0 0 Disabled/HI-Z Slow Receive/HI-Z Slow Receive/HI-Z 1 0 1 Slow Receive/HI-Z Disabled/HI-Z Slow Receive/HI-Z 1 1 0 Disabled/HI-Z Slow Receive/HI-Z Slow Receive/HI-Z 1 1 1 Slow Receive/HI-Z Disabled/HI-Z Slow Receive/HI-Z which improves noise margins. The polarity of each Shutdown Control receiver’s input threshold is shown in Tables 1a and 1b. In shutdown mode, the charge pumps are turned off, In normal operating mode, receiver inputs are internally V+ is pulled down to VCC, V- is pulled to ground, and connected to ground with 5kΩ resistors. So uncon- the transmitter outputs are disabled. This reduces sup- nected receivers with positive input thresholds have ply current typically to 4µA. The time required to exit high outputs, and those with negative input thresholds shutdown is about 250µs, as shown in Figure 3. have low outputs. Receivers When shut down, all receivers have positive thresholds. Receiver outputs never go into a high-impedance state; This allows the receiver inputs to respond to they are always active, even in shutdown mode (see TTL-/CMOS-logic levels, as well as RS-232 levels. The Table 2). These awake-in-shutdown receivers are use- guaranteed 0.8V input threshold ensures that receivers ful for monitoring external activity (for example, on RI), shorted to ground will have a logic 1 output. Also, the while maintaining minimal power consumption. 300kΩinput resistance to ground ensures that a receiv- Receivers in shutdown mode are slower (20kbps) than er with its input left open will also have a logic 1 output. when not shut down (116kbps), and lack the hysteresis The receiver’s 0.5V of hysteresis provides clean output present in normal operation. transitions, even with slow rise-time and fall-time sig- nals with moderate amounts of noise and ringing. The Drivers receivers have no hysteresis in shutdown mode. The driver outputs are high impedance in shutdown mode, even when back-driven with voltages up HI-Z Control to ±15V. The receiver inputs are terminated with 5kΩresistors, to comply with the requirements of EIA/TIA-232E. __________Applications Information However, these internal resistors can be disconnected by taking the HI-Z control pin to a logic high. This Capacitor Selection makes all of the MAX214’s receiver inputs high imped- The type of capacitor (C1 to C4) used is not critical for ance, and facilitates the transmission of RS-232 data proper operation. The MAX214 requires 1µF capaci- from a single transmitter to multiple receivers. In this tors, although in all cases capacitors of up to 10µF case, all but one of the receiving ICs should be put into can be used without harm. Ceramic dielectrics are the high input-impedance state. suggested for the 1µF capacitors. 8 _______________________________________________________________________________________

Programmable DTE/DCE, +5V RS-232 Transceiver When using the minimum recommended capacitor pump capacitor sizes up to 10µF reduces the imped- M values, make sure the capacitance value does not ance of the V+ and V- outputs. degrade excessively as the operating temperature High Data Rates A varies. If in doubt, use capacitors with a The MAX214 maintains the RS-232 ±5.0V minimum X larger nominal value (for example, 2 times larger). driver output voltage even at high data rates. The 2 The effective series resistance (ESR) of the capaci- Typical Operating Characteristicsshow transmitter out- tors may vary over temperature and increase put voltage levels driving 3kΩ in parallel with various 1 when below 0°C. ESR influences the amount of rip- 4 capacitive loads at data rates up to 120kbps. ple on V+ and V-, so if low ripple is required over wide temperature ranges, use larger capacitors or low-ESR types. To reduce the output impedance at V+ and V-, use larger capacitors (up to 10µF). This can be useful +10V when “stealing” power from V+ or from V-. A +5V Driver Outputs when Exiting Shutdown Figure 3 shows the MAX214 driver outputs when exiting 0V shutdown. As they become active, the two driver out- -5V puts are shown going to opposite RS-232 levels (one B driver input is high, the other is low). Each driver is +5V -10V loaded with 3kΩin parallel with 2.5nF. 0V C Power-Supply Bypassing Decouple VCC to ground with a capacitor of the same value as the charge-pump capacitors. A = TRANSMITTER OUTPUT HIGH, +5V/div(cid:13) B = TRANSMITTER OUTPUT LOW, +5V/div(cid:13) V+ and V- as Power Supplies C = SHDN INPUT, +5V/div(cid:13) (cid:13) A small amount of power can be drawn from V+ and V-, HORIZONTAL = 200m s although this will reduce noise margins. See the Output Voltage vs. Load Current graph in the Typical Operating Characteristics. Increasing the charge- Figure 3. Transmitter Outputs When Exiting Shutdown _______________________________________________________________________________________ 9

Programmable DTE/DCE, +5V RS-232 Transceiver 4 1 2 X (cid:13) STANDARD(cid:13) (cid:13) PC1(cid:13) RS-232(cid:13) PC2(cid:13) A (DTE MODE) CABLE (DCE MODE) M 5(cid:13) TA(cid:13) TRA(cid:13) 9(cid:13) 3(cid:13) TxD(cid:13) 3(cid:13) 9(cid:13) TRA(cid:13) TA(cid:13) 5(cid:13) 6(cid:13) RA(cid:13) RTA(cid:13) 10(cid:13) 2(cid:13) RxD(cid:13) 2(cid:13) 10(cid:13) RTA(cid:13) RA(cid:13) 6(cid:13) 25(cid:13) TB(cid:13) TRB(cid:13) 20(cid:13) 7(cid:13) RTS(cid:13) 7(cid:13) 20(cid:13) TRB(cid:13) TB(cid:13) 25(cid:13) 23(cid:13) RB(cid:13) RTB(cid:13) 19(cid:13) 8(cid:13) CTS(cid:13) 8(cid:13) 19(cid:13) RTB(cid:13) RB(cid:13) 23(cid:13) 24(cid:13) TC(cid:13) TRC(cid:13) 18(cid:13) 4(cid:13) DTR(cid:13) 4(cid:13) 18(cid:13) TRC(cid:13) TC(cid:13) 24(cid:13) 22(cid:13) RC(cid:13) RTC(cid:13) 17(cid:13) 6(cid:13) DSR(cid:13) 6(cid:13) 17(cid:13) RTC(cid:13) RC(cid:13) 22(cid:13) (cid:13) (cid:13) (cid:13) (cid:13) (cid:13) (cid:13) (cid:13) (cid:13) (cid:13) 7(cid:13) RDC(cid:13) RDTC(cid:13) 11(cid:13) 1(cid:13) DCD(cid:13) 1(cid:13) 11(cid:13) RDTC(cid:13) RDC(cid:13) 7(cid:13) MAX214 MAX214 8 RE RRE 12 9 RI 9 12 RRE RE 8 HIGH HIGH HI-Z SHDN DTE/DCE HI-Z SHDN DTE/DCE 3 26 21 DB-9 CONNECTORS 3 26 21 VCC POWER CONNECTIONS OMITTED FOR CLARITY. Figure 4. Typical Application Circuit Showing 2 PCs with Both DTE and DCE Operation 10 ______________________________________________________________________________________

Programmable DTE/DCE, +5V RS-232 Transceiver Table 3. Summary of EIA/TIA-232E, V.28 ___________________Chip Topography M Specifications A EIA/TIA-232E, V.28 C2- C1- SHDN X PARAMETER CONDITIONS SPECIFICATIONS HI-Z C2+ C1+ TB 2 Driver Output 3kW to 7kW load +5.0V to +15V 1 Voltage TA TC 0 Level 3kW to 7kW load -5.0V to -15V 4 1 Level Output Level, Max No load ±25V RA RB Data Rate 3kW ≤RL≤7kW, Up to 20kbits/sec CL≤2500pF RDC RC 0.178"(cid:13) Receiver Input +3.0V to +15V 4.52mm Voltage 0 Level -3.0V to -15V RE 1 Level DTE/DCE Input Level, Max ±25V Instantaneous 3kW ≤RL≤7kW, 30V/m s TRA TRB Slew Rate, Max CL≤2500pF RTA RTB Driver Output Short-Circuit 100mA Current, Max RRE GND V+ TRC V.28 1ms or 3% of the RDTC V- VCC RTC Transition Rate on period 0.156"(cid:13) Driver Output EIA/TIA-232E 4% of the period 3.96mm DRerisviesrt aOnucteput -2V < VOUT< +2V 300W TSRUABNSTSRISATTOER C COONUNNETC: T 6E9D4 T;O V+. Table 4. DB9/DB25 Cable Connections Commonly Used for EIA/TIA-232 and V.24 Asynchronous Interfaces DB9 PIN DB25 PIN NAME SYMBOL FUNCTION Received Line Signal Detector, sometimes 1 8 DCD Handshake from DCE called Data Carrier Detect 2 3 Receive Data RxD Data from DCE 3 2 Transmit Data TxD Data from DTE 4 20 Data Terminal Ready DTR Handshake from DTE 5 7 Signal Ground GND Reference point for signals 6 6 Data Set Ready DSR Handshake from DCE 7 4 Request to Send RTS Handshake from DTE 8 5 Clear to Send CTS Handshake from DCE 9 22 Ring Indicator RI Handshake from DCE ______________________________________________________________________________________ 11

Programmable DTE/DCE, +5V RS-232 Transceiver 4 ________________________________________________________Package Information 1 2 INCHES MILLIMETERS DIM(cid:13) X (cid:13) MIN(cid:13) MAX(cid:13) MIN(cid:13) MAX(cid:13) D1 A(cid:13) –(cid:13) 0.200(cid:13) –(cid:13) 5.08(cid:13) A A1(cid:13) 0.015(cid:13) –(cid:13) 0.38(cid:13) –(cid:13) M A2(cid:13) 0.125(cid:13) 0.175(cid:13) 3.18(cid:13) 4.45(cid:13) A3(cid:13) 0.055(cid:13) 0.080(cid:13) 1.40(cid:13) 2.03(cid:13) B(cid:13) 0.016(cid:13) 0.020(cid:13) 0.41(cid:13) 0.51(cid:13) B1(cid:13) 0.045(cid:13) 0.065(cid:13) 1.14(cid:13) 1.65(cid:13) C(cid:13) 0.008(cid:13) 0.012(cid:13) 0.20(cid:13) 0.30(cid:13) D(cid:13) 1.430(cid:13) 1.470(cid:13) 36.32(cid:13) 37.34(cid:13) D1(cid:13) 0.050(cid:13) 0.090(cid:13) 1.27(cid:13) 2.29(cid:13) E E(cid:13) 0.600(cid:13) 0.625(cid:13) 15.24(cid:13) 15.88(cid:13) A2 A3 E1(cid:13) 0.525(cid:13) 0.575(cid:13) 13.34(cid:13) 14.61(cid:13) E1 A D e(cid:13) 0(cid:13).100 BSC(cid:13) (cid:13)2.54 BSC(cid:13) eA(cid:13) 0(cid:13).600 BSC(cid:13) 1(cid:13)5.24 BSC(cid:13) eB(cid:13) –(cid:13) 0.700(cid:13) –(cid:13) 17.78(cid:13) a L(cid:13) 0.125(cid:13) 0.150(cid:13) 3.18(cid:13) 3.81(cid:13) a 0˚ 15˚ 0˚ 15˚ A1 21-342A e C 28-PIN PLASTIC(cid:13) L B1 eA DUAL-IN-LINE(cid:13) B eB PACKAGE INCHES MILLIMETERS DIM(cid:13) (cid:13) MIN(cid:13) MAX(cid:13) MIN(cid:13) MAX(cid:13) A(cid:13) 0.093(cid:13) 0.104(cid:13) 2.35(cid:13) 2.65(cid:13) A1(cid:13) 0.004(cid:13) 0.012(cid:13) 0.10(cid:13) 0.30(cid:13) B(cid:13) 0.014(cid:13) 0.019(cid:13) 0.35(cid:13) 0.49(cid:13) C(cid:13) 0.009(cid:13) 0.013(cid:13) 0.23(cid:13) 0.32(cid:13) E H D(cid:13) 0.697(cid:13) 0.713(cid:13) 17.70(cid:13) 18.10(cid:13) E(cid:13) 0.291(cid:13) 0.299(cid:13) 7.40(cid:13) 7.60(cid:13) e(cid:13) 0(cid:13).050 BSC(cid:13) (cid:13)1.27 BSC(cid:13) H(cid:13) 0.394(cid:13) 0.419(cid:13) 10.00(cid:13) 10.65(cid:13) h(cid:13) 0.010(cid:13) 0.030(cid:13) 0.25(cid:13) 0.75(cid:13) L(cid:13) 0.016(cid:13) 0.050(cid:13) 0.40(cid:13) 1.27(cid:13) a 0˚ 8˚ 0˚ 8˚ 21-343A D h x 45˚ a A 28-PIN PLASTIC(cid:13) 0.127mm(cid:13) SMALL-OUTLINE(cid:13) 0.004in. e B A1 C L PACKAGE 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. 12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 1995 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

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