MAX214 19-0199; Rev 1; 8/95 Programmable DTE/DCE, +5V RS-232 Transceiver _______________General Description ____________________________Features The MAX214 +5V RS-232 transceiver provides a com-'Eliminates Null Modem Cables plete, 8-line, software-configurable, DTE or DCE port 'Programmable DTE or DCE Serial Port RS-232 interface. Tx, Rx, RTS, CTS, DTR, DSR, DCD, and RI circuits can be configured as either Data '1µF Charge-Pump Capacitors Terminal Equipment (DTE) or Data Circuit-Terminating Equipment (DCE) using the DTE/DCE control pin. The'116kbps Data Rate—Guaranteed MAX214 eliminates the need to swap cables when '20µA Shutdown Mode switching between DTE and DCE configurations. 'Receivers Active in Shutdown ________________________Applications 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 MAX214EWI -40°C to +85°C 28 Wide SO +5V * Dice are specified at TA = +25°C. 1μF 16 1μF 27 V CC __________________Pin Configuration C1+ 15 1μF V+ 28 C1- 1 MAX214 C2+ 14 1μF TOP VIEW V- 2 C2- 1μF 5 TA DTE TRA 9 1 28 C1- C2+ DCE C2- 2 27 C1+ 6 RA RTA 10 DTE 3 26 SHDN HI-Z 20 25 TB DTE TRB 4 25 N.C. TB DCE TC TA 5 24 23 RB RTB 19 MAX214 DTE RA 6 23 RB 24 TC TRC 18 DTE RDC 7 22 RC DCE RE 8 21 DTE/DCE 22 RC RTC 17 DTE TRA 9 20 TRB DCE DCE 7 RDC 11 RDTC 10 19 RTB RTA DTE DTE 18 TRC RDTC 11 8 RE RRE 12 RRE 12 17 RTC 21 DTE/DCE GND 13 16 V 26 CC SHDN 3 V- 14 15 V+ HI-Z GND DIP/SO 13 ________________________________________________________________ Maxim Integrated Products 1 Call toll free 1-800-998-8800 for free samples or literature. Programmable DTE/DCE, +5V RS-232 Transceiver ABSOLUTE MAXIMUM RATINGS V ...........................................................................-0.3V to +6V Continuous Power Dissipation (TA = +70°C) CC Input Voltages Plastic DIP (derate 9.09mW/°C above +70°C) .............727mW T , DTE/DCE, SHDN HI-Z ......................-0.3V to (V + 0.3V) Wide SO (derate 12.50mW/°C above +70°C) ............1000mW IN CC R ....................................................................................±15V Operating Temperature Ranges: IN Output Voltages: MAX214C I ..............................................0°C to +70°C – T ..................................................................................±15V MAX214E I ..........................................-40°C to +85°C OUT – R ........................................................-0.3V to (V + 0.3V) Storage Temperature Range......................-65°C to +150°C OUT CC Short-Circuit (one output at a time) Lead Temperature (soldering, 10sec) .......................+300°C T to GND ...........................................................Continuous OUT R to GND...........................................................Continuous OUT 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 (V = 4.5V to 5.5V, C1 to C4 = 1mF, T = T to T , unless otherwise noted.) CC A MIN MAX 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 110 50 mA Logic Input Pull-Up Current Shutdown ±0.01 ±1 Output Voltage Swing All transmitter outputs loaded with 3kWto ground ±5.0 ±7.5 V WTransmitter Output Resistance V = V+ = V- = 0V, V = ±2V (Note 1) 300 300k CC OUT Output Short-Circuit Current V = 0V ±7 ±25 mA OUT 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 V = 5V, normal operation, SHDN = 0V (no hysteresis Positive Threshold Input CC 0.2 0.5 1.0 V in shutdown) Hysteresis Normal operation, SHDN = 0V -2.6 -1.9 Negative Threshold Input Low T = +25°C, V = 5V V A CC Shutdown, SHDN = 5V 0.8 1.3 Normal operation, SHDN = 0V -1.5 -0.2 Negative Threshold Input High T = +25°C, V = 5V V A CC Shutdown, SHDN = 5V 1.3 2.4 V = 5V, normal operation, SHDN = 0V (no hysteresis Negative Threshold Input CC 0.2 0.4 1.0 V in shutdown) Hysteresis HI-Z = 0V and SHDN = 0V 35 7 Input Resistance kW HI-Z = 5V or SHDN = 5V 100 300 TTL/CMOS Output Voltage Low I = 3.2mA 0.2 0.4 V OUT TTL/CMOS Output Voltage High IOUT = -1.0mA 3.5 VCC - 0.2 V 2 _______________________________________________________________________________________ MAX214 MAX214 Programmable DTE/DCE, +5V RS-232 Transceiver ELECTRICAL CHARACTERISTICS (continued) (V = 4.5V to 5.5V, C1 to C4 = 1mF, T = T to T , unless otherwise noted.) CC A MIN MAX PARAMETER CONDITIONS MIN TYP MAX UNITS POWER SUPPLY V Supply Current No load, T = +25°C 920 mA CC A T = +25°C 420 A DTE/DCE = 0V, SHDN = mA Shutdown Supply Current HI-Z = , Figure 1 V CC T = T to T 50 A MIN MAX 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 ±1mA AC CHARACTERISTICS Normal operation, transmitters and receivers 200 116 Data Rate kbps Receivers in shutdown mode 20 T A = +25°C, VCC = 5V, RL = 3kWto 7kW, Transition-Region Slew Rate 612 30 V/ms C = to 2500pF, L measured from 3V to -3V or -3V to 3V t 1.3 3.5 Transmitter Propagation Delay, PHLT ms TTL to RS-232 (Normal Operation) t 1.4 3.5 PLHT Transmitter + to - Propagation-Delay t - t 100 ns PHLT PLHT Difference (Normal Operation) Receiver Propagation Delay, ms t , t 0.4 1.5 PHLR PLHR RS-232 to TTL (Normal Operation) t 0.4 10 PHLR Receiver Propagation Delay, ms RS-232 to TTL (Shutdown Mode) t 1.5 10 PLHR Receiver Propagation-Delay Difference t - t‰PHLT PLHT‰100 ns (Normal Operation) MODE-CHANGE TIMING (DTE/DCE) Transmitter Enable Time t (includes charge-pump start-up time) 250ms TEN Transmitter Disable Time tTTR 600 ns Transmitter DTE/DCE Switch Time t 600 ns TSW Receiver DTE/DCE Switch Time t 300 ns RSW Receiver Termination-Resistor (SHDN = 0V) 300 ns Connect/Disconnect Time Receiver Termination-Resistor Connect ms 250 Entering SHDN Time Receiver Termination-Resistor 300 ns Disconnect Exiting SHDN Time Note 1: The 300Wminimum is the EIA/TIA-232E specification, but the actual resistance when in shutdown mode or when V = 0V CC is typically 300kW. _______________________________________________________________________________________ 3 Programmable DTE/DCE, +5V RS-232 Transceiver __________________________________________Typical Operating Characteristics (V = 5V, C1 to C4 = 1mF, all transmitters loaded with 3kWin parallel with 2.5nF, T = +25°C, unless otherwise noted.) CC A TRANSMITTER OUTPUT VOLTAGE (V ) TRANSMITTER OUTPUT VOLTAGE (VOH) OL vs. LOAD CAPACITANCE vs. LOAD CAPACITANCE TRANSMITTER OUTPUT VOLTAGE (V ) OH AT DIFFERENT DATA RATES AT DIFFERENT DATA RATES vs. V POSITIVE SUPPLY VOLTAGE CC -5.5 9.0 7.6 20kbps 1 TRANSMITTER LOADED 7.4 2 TRANSMITTERS LOADED -6.0 8.5 120kbps 7.2 3 TRANSMITTERS LOADED 64kbps -6.5 7.0 8.0 -7.0 6.8 64kbps 120kbps 7.5 6.6 -7.5 20kbps 6.4 7.0 -8.0 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) V (V) CC TRANSMITTER OUTPUT VOLTAGES TRANSMITTER OUTPUT VOLTAGE (V OL) vs. V+, V- LOAD CURRENT SLEW RATE vs. LOAD CAPACITANCE vs. POSITIVE SUPPLY VOLTAGE -7.0 10 20 SLEW+ 3 TRANSMITTERS LOADED 8 3 TRANSMITTERS LOADED 18 2 TRANSMITTERS LOADED 6 SLEW- -7.5 16 3 TRANSMITTERS LOADED 1 TRANSMITTER LOADED 4 V+ AND V- V- LOADED, V+ LOADED, 14 2 EQUALLY NO LOAD NO LOAD -8.0 SLEW+ LOADED ON V+ ON V- 1 TRANSMITTER LOADED 0 12 -2 -8.5 10 ALL TRANSMITTERS UNLOADED, 0kbps -4 8 -6 SLEW- -9.0 6 1 TRANSMITTER LOADED -8 DATA RATE = 0kbps 4 -9.5 -10 0 2000 4000 6000 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 LOAD CURRENT (mA) LOAD CAPACITANCE (pF) V (V) CC 4 _______________________________________________________________________________________ MAX214 V (V) OL V (V) OL MAX214-01 MAX214-04 T +, T (V) OUT OUT- V (V) OH MAX214-05 MAX214-02 V (V) SLEW RATE (V/μs) OH MAX214-06 MAX214-03 MAX214 Programmable DTE/DCE, +5V RS-232 Transceiver ______________________________________________________________Pin Description PIN NAME FUNCTION 1, 2 C2+, C2- Terminals for negative charge-pump capacitor 3 HI-Z RS-232 receiver impedance control. Take high to disconnect the termination resistor. 4 N.C. No connect—not internally connected 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- -2V voltage generated by the charge pump CC 15 V+ +2V voltage generated by the charge pump CC 16 V +4.5V to +5.5V supply voltage CC 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 DTE/DCE Operation _______________Detailed Description 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 V by an internal CC stay active for simple detection of ring indicator signals. resistor, and V- falls to GND. _______________________________________________________________________________________ 5 MAX214 Programmable DTE/DCE, +5V RS-232 Transceiver Table 1a. DTE-Operation Pin Configurations TTL/CMOS MAX214 MAX214 RS-232 DB-25 INPUT FUNCTION I/O LABEL PIN PIN I/O LABEL PIN THRESHOLD Transmitter (TxD) 5 9 TxD 2 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 _______________________________________________________________________________________ MAX214 MAX214 Programmable DTE/DCE, +5V RS-232 Transceiver RS-232 Drivers With VCC = 5V, the typical driver output voltage swing I SHDN is ±8V when loaded with a nominal 5kΩ RS-232 +5.5V receiver. Under worst-case operating conditions 1µF 1µF (including 116kbps data rate, 3kΩ ŒŒ 2500pF load, VCC = 4.5V, maximum rated temperature) the output V CC C1+ V+ swing is guaranteed to meet the ±5V minimum speci- 1µF fied by EIA/TIA-232 and V.28. The open-circuit output 1µF C1- voltage swing ranges from (V+ - 0.6V) to V-. MAX214 V- C2+ Input thresholds are both CMOS and TTL compatible. +5V 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 T T OUT force the outputs of unused drivers low. The input IN +5.5V pull-up resistors typically source 10µA; in shutdown 3k mode, they are disconnected to reduce supply current. Rx +5.5V R R OUT IN When in low-power shutdown mode, the driver outputs 0V OR +5.5V are turned off and their leakage current is less than 5k DTE/DCE DRIVE 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 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 S2 S5 S6 C1+ C2+ V CC GND C1 C3 C2 I + R + I - R - L L L L C4 S3 S4 S7 S8 GND V V - CC C1- C2- 120kHz Figure 2. Charge-Pump Diagram _______________________________________________________________________________________ 7 Programmable DTE/DCE, +5V RS-232 Transceiver Table 2. Control Pin Configurations CONTROL INPUTS RS-232 PINS SHUTDOWN HI-Z DTE/DCE TRA, TRB, TRC RTA, RTB, RTC, RDTC RRE Receive Mode/5kWReceive Mode/5kW0 0 0 Transmit Mode 0 0 1 Receive Mode/5kWTransmit 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 V , V- is pulled to ground, and CC 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. 300kΩ input 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- Drivers nals with moderate amounts of noise and ringing. The The driver outputs are high impedance in shutdown receivers have no hysteresis in shutdown mode. mode, even when back-driven with voltages up HI-Z Control to ±15V. The receiver inputs are terminated with 5kΩ resistors, 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 _______________________________________________________________________________________ MAX214 MAX214 Programmable DTE/DCE, +5V RS-232 Transceiver When using the minimum recommended capacitor pump capacitor sizes up to 10µF reduces the imped- values, make sure the capacitance value does not ance of the V+ and V- outputs. degrade excessively as the operating temperature High Data Rates varies. If in doubt, use capacitors with a The MAX214 maintains the RS-232 ±5.0V minimum larger nominal value (for example, 2 times larger). driver output voltage even at high data rates. The The effective series resistance (ESR) of the capaci- Typical Operating Characteristics show transmitter out- tors may vary over temperature and increase put voltage levels driving 3kΩ in parallel with various when below 0°C. ESR influences the amount of rip- 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 0V Figure 3 shows the MAX214 driver outputs when exiting -5V shutdown. As they become active, the two driver out- puts are shown going to opposite RS-232 levels (one B +5V -10V driver input is high, the other is low). Each driver is loaded with 3kΩ in parallel with 2.5nF. C 0V Power-Supply Bypassing Decouple V to ground with a capacitor of the same CC A = TRANSMITTER OUTPUT HIGH, +5V/div value as the charge-pump capacitors. B = TRANSMITTER OUTPUT LOW, +5V/div C = SHDN INPUT, +5V/div V+ and V- as Power Supplies A small amount of power can be drawn from V+ and V-, HORIZONTAL = 200μs although this will reduce noise margins. See the Output Voltage vs. Load Current graph in the Typical Figure 3. Transmitter Outputs When Exiting Shutdown Operating Characteristics. Increasing the charge- _______________________________________________________________________________________ 9 Programmable DTE/DCE, +5V RS-232 Transceiver STANDARD PC1 PC2 RS-232 (DTE MODE) (DCE MODE) CABLE 5 TA TRA 9 TxD 9 TRA TA 5 3 3 6 RA RTA 10 RxD 10 RTA RA 6 2 2 25 TB TRB 20 RTS 20 TRB TB 25 7 7 23 RB RTB 19 CTS 19 RTB RB 23 8 8 24 TC TRC 18 DTR 18 TRC TC 24 4 4 22 RC RTC 17 DSR 17 RTC RC 22 6 6 7 RDC RDTC 11 DCD 11 RDTC RDC 7 1 1 MAX214 MAX214 8 RE RRE 12 RI 12 RRE RE 8 9 9 HIGH HIGH HI-Z SHDN DTE/DCE HI-Z SHDN DTE/DCE DB-9 CONNECTORS 3 26 21 3 26 21 V CC POWER CONNECTIONS OMITTED FOR CLARITY. Figure 4. Typical Application Circuit Showing 2 PCs with Both DTE and DCE Operation 10 ______________________________________________________________________________________ MAX214 MAX214 Programmable DTE/DCE, +5V RS-232 Transceiver ___________________Chip Topography Table 3. Summary of EIA/TIA-232E, V.28 Specifications C2- C1- SHDN EIA/TIA-232E, V.28 PARAMETER CONDITIONS HI-Z C2+ C1+ TB SPECIFICATIONS Driver Output 3kW to 7kW load +5.0V to +15V TC TA Voltage 0 Level 3kW to 7kW load -5.0V to -15V 1 Level No load ±25V Output Level, Max RA RB 3kW≤ R ≤ 7kW, L Data Rate Up to 20kbits/sec C ≤ 2500pF L 0.178" RDC RC 4.52mm Receiver Input +3.0V to +15V Voltage RE 0 Level -3.0V to -15V DTE/DCE 1 Level ±25V Input Level, Max 3kW≤ R ≤ 7kW, Instantaneous L TRA TRB 30V/ms Slew Rate, Max C ≤ 2500pF L RTA RTB Driver Output Short-Circuit 100mA Current, Max RRE GND V+ TRC 1ms or 3% of the RDTC V- V RTC CC V.28 period Transition Rate on 0.156" Driver Output 3.96mm EIA/TIA-232E 4% of the period TRANSISTOR COUNT: 694; Driver Output -2V < V < +2V 300WOUT Resistance SUBSTRATE CONNECTED TO 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 ________________________________________________________Package Information INCHES MILLIMETERS DIM MIN MAX MIN MAX D1 A – 0.200 – 5.08 A1 0.015 – 0.38 – A2 0.125 0.175 3.18 4.45 A3 0.055 0.080 1.40 2.03 B 0.016 0.020 0.41 0.51 B1 0.045 0.065 1.14 1.65 C 0.008 0.012 0.20 0.30 D 1.430 1.470 36.32 37.34 D1 0.050 0.090 1.27 2.29 E E 0.600 0.625 15.24 15.88 A2 A3 E1 0.525 0.575 13.34 14.61 E1 D e 0.100 BSC 2.54 BSC A e 0.600 BSC 15.24 BSC A e – 0.700 – 17.78 B L 0.125 0.150 3.18 3.81 α α 0˚ 15˚ 0˚ 15˚ 21-342A A1 e C 28-PIN PLASTIC L e A B1 DUAL-IN-LINE e B B PACKAGE INCHES MILLIMETERS DIM MIN MAX MIN MAX A 0.093 0.104 2.35 2.65 A1 0.004 0.012 0.10 0.30 B 0.014 0.019 0.35 0.49 C 0.009 0.013 0.23 0.32 E H D 0.697 0.713 17.70 18.10 E 0.291 0.299 7.40 7.60 e 0.050 BSC 1.27 BSC H 0.394 0.419 10.00 10.65 h 0.010 0.030 0.25 0.75 L 0.016 0.050 0.40 1.27 α 0˚ 8˚ 0˚ 8˚ 21-343A D h x 45˚ α A 28-PIN PLASTIC 0.127mm 0.004in. SMALL-OUTLINE A1 PACKAGE C e B L 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. MAX214