SN75LBC784 QUADRUPLE RS-423-B DRIVER/RECEIVER SLLS187A – NOVEMBER 1994 – REVISED AUGUST 1995 D D D D D D D DW PACKAGE (TOP VIEW) Four Independent Drivers and Receivers Driver Slew Rate Controlled by a Single Resistor Fast Driver Transition Times Down to 1.5 µs and Receiver Transition Times of 20 ns Typ Internal Thermal-Overload Protection RS-423-B Inputs and Outputs Designed to Withstand ± 25 V ESD Protection Exceeds 2000 V Per MIL-STD-833C Method 3015 LinBICMOS Process Technology 3A 3Z BIAS 4A 4Z BIAS VSS GND 4B 4Y 3B 3Y 3C 4C description The SN75LBC784 performs as four independent RS-423-B driver/receiver pairs designed to interface data terminal equipment (DTE) with data circuit-terminating equipment (DCE) at rates up to 120 kbps and distances to 1.2 km. The SN75LBC784 provides an upgrade to the RS-232 serial interface and can be backward compatible with existing serial ports while offering the higher performance required by new faster peripherals, such as v.34 (v.fast) modems. The RS-232 standard, and subsequent revisions, only support data rates up to 20 kbps over about 15 meters of cable. For RS-423-B the data rate is increased to 120 kbps and transmission distance to 1.2 km by reducing the maximum output signal swing, increasing the driver output current, and reducing the receiver input voltage thresholds. 1 28 2 27 3 26 4 25 5 24 6 23 7 22 8 21 9 20 10 19 11 18 12 17 13 16 14 15 BIAS 2Z 2A BIAS 1Z 1A Rws VDD 1Y 1B 2Y 2B 2C 1C FUNCTION TABLE A INPUTS B C L H L H L L H H H H L L L H L H L L H H OUTPUTS Z Y H H L H H L L L H ? L L ? L H ? H L ? H H = high level, L = low level, X = irrelevant, Z = high impedance (off) ? = indeterminate The receivers consist of differential comparators with hysteresis and resistive attenuation on the inputs. The resistive attenuation improves the input common mode range and also provides additional protection from ESD and over-voltage stress. The differential and common mode input impedances are sufficiently high to meet RS-423-B. When a differential voltage input of 500 mV is applied across the entire common mode range ( see Figure 5), the receiver characteristics and bias voltage allow the receiver to remain in its intended binary state. The drivers meet all RS-423-B specifications with built-in current limits and thermal-overload protection. Slew-rate controlling circuitry is included in the design, which is adjusted to suit the application by means of an external resistor (Rws). The slew rate controlling circuitry also has a default mode – if the Rws pin is shorted to 5 V externally, the transistion time defaults to approximately 1.5 ms. The BIAS input, when shorted to 5 V externally, provides the internal node voltages. The receiver is compatible to RS-232 with the use of external input resistors to meet the RS-232 input resistance specification of 3 kΩ to 7 kΩ. The SN75LBC784 is characterized for operation over the temperature range of 0°C to 70°C. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. LinBiCMOS is a trademark of Texas Instruments Incorporated. Copyright 1995, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 SN75LBC784 QUADRUPLE RS-423-B DRIVER/RECEIVER SLLS187A – NOVEMBER 1994 – REVISED AUGUST 1995 logic diagram (positive logic) 3A 4A 1A 2A 1 12 4 10 23 20 26 18 3Y 3Z 4Y 4Z 1Y 1Z 2Y 2Z 2 5 27 24 11 + _ 13 9 + _ 14 19 + _ 15 17 + _ 16 3B 3C 4B 4C 1B 1C 2B 2C absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Positive supply voltage, VDD (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 V Negative supply voltage, VSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 14 V Bias voltage, Vbias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.75 V Receiver input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 30 V to 30 V Driver input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 5.75 V Driver output voltage range (supplies at 0 V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 30 V to 30 V Driver output voltage range (supplies at ± 12 V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 25 V to 25 V Continuous power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C Case temperature for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C † 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 under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTE 1: All voltages are with respect to network ground terminal. DISSIPATION RATING TABLE PACKAGE TA ≤ 25°C POWER RATING DERATING FACTOR† ABOVE TA = 25°C TA = 70°C POWER RATING DW 1348 mW 10.8 mW/°C 862 mW † Derating factors are the inverse of the junction-to-ambient thermal resistance when board-mounted with no air flow. recommended operating conditions MIN NOM MAX UNIT Supply voltage, VDD 10.8 12 13.2 V Supply voltage, VSS – 10.8 – 12 – 13.2 V 2 5 5.5 V Bias voltage, Vbias High-level input voltage, VIH Driver 2 Low-level input voltage, VIL Driver 0.8 V High-level output current, IOH Receiver –4 mA Low-level output current, IOL Receiver 4 mA 820 kΩ 70 °C Rws slew rate control resistor 20 Operating free-air temperature, TA 2 0 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 V 82 SN75LBC784 QUADRUPLE RS-423-B DRIVER/RECEIVER SLLS187A – NOVEMBER 1994 – REVISED AUGUST 1995 DRIVER SECTION electrical characteristics over recommended ranges of supply voltage and operating free-air temperature, VDD = 10.8 V to 13.2 V, VSS = –10.8 V to –13.2 V, TA = 0°C to 70°C (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT VOH VOL High-level output voltage Open circuit or RL = 450 Ω 4 5.5 6 Low-level output voltage Open circuit or RL = 450 Ω –6 – 5.5 –4 V IIH IIL High-level input current VI = 2.4 V to 5.5 V VI = 0 V to 0.8 V 100 µA IO IOS(H) Output leakage current IOS(L) Low-level short circuit output current Low-level input current High-level short circuit output current IDD Supply current ISS Supply current Ibias Bias current µA – 100 VDD = VSS = 0, VI = 5 V, VO = ± 6 V VO = 0 VI = 0, No load VO = 0 V 100 µA 15 45 mA – 45 – 15 mA – 100 10 12 60 70 No load – 10 – 12 RL = 450 Ω – 60 – 70 RL = 450 Ω 400 mA mA µA switching characteristics over recommended ranges of supply voltage and operating free-air temperature, VDD = 10.8 V to 13.2 V, VSS = –10.8 V to –13.2 V, TA = 0°C to 70°C (unless otherwise noted) PARAMETER TEST CONDITIONS MIN Rws = 0 kΩ tTLH Transition time, low-to-high level (see Figure 1) CL = 50 pF, MAX UNIT 1.5 Rws = 20 kΩ 1.5 2.1 2.7 Rws = 82 kΩ 5 8 11 Rws = 820 kΩ RL = 450 Ω, VWS = 5 V TYP µs 80 1.5 Rws = 0 kΩ Rws = 20 kΩ 1.5 2.1 2.7 Rws = 82 kΩ 5 8 11 µs tTHL Transition time, high-to-low level (see Figure 1) SR Output slew rate Rws = 20 kΩ 15 V/µs tsk Output skew (see Figure 4) |tPHL – tPLH| Rws = 82 kΩ 1 µs Rws = 820 kΩ POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 80 3 SN75LBC784 QUADRUPLE RS-423-B DRIVER/RECEIVER SLLS187A – NOVEMBER 1994 – REVISED AUGUST 1995 RECEIVER SECTION electrical characteristics over recommended ranges of supply voltage and operating free-air temperature, VDD = 10.8 V to 13.2 V, VSS = –10.8 V to –13.2 V, TA = 0°C to 70°C (unless otherwise noted) PARAMETER VIT IT+ Positive input threshold voltage VIT IT– Negative input threshold voltage II Input current Vhys Hysteresis (VIT + – VIT –) TEST CONDITIONS MIN TYP MAX 200 With 500 Ω series resistor 400 – 200 With 500 Ω series resistor VI = 10 V VI = – 10 V – 400 Other input to GND 1.3 – 3.25 – 1.3 20 40 VOH High level output voltage (see Note 2) High-level IO = –20 µA IO = – 4 mA VOL IRX Low-level output voltage IO = 20 µA to 4 mA VID Vofs Differential input voltage Receiver inputs open circuit 1.6 Fail safe output voltage See Note 3 3.5 3.25 150 3.5 5 2.4 5 RX short circuit current 2.1 UNIT mV mV mA mV V 0.4 V 50 mA 2.6 V V NOTES: 2. Device has an internal RX supply regulator. Maximum RX logic output voltage under no load is thus defined by an internal voltage value. This is nominally set to 4.5 V with a tolerance of ± 5%. 3. One input at ground, other input open circuit, IO = –20 µA, or both open circuit. switching characteristics over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) test conditions: VDD = 10.8 V to 13.2 V, VSS = – 10.8 V to – 13.2 V, TA = 0°C to 70°C (unless otherwise noted) PARAMETER TEST CONDITIONS tPLH tPHL Propagation Delay time low-to-high (see Figure 2) tTHL tTLH Transition time high-to-low (see Figure 3) 4 Propagation delay time high-to-low (see Figure 2) NOM MAX UNIT 0 15 0.15 1 µs 20 200 ns CL = 50 pF Transition time low-to-high (see Figure 3) POST OFFICE BOX 655303 MIN • DALLAS, TEXAS 75265 SN75LBC784 QUADRUPLE RS-423-B DRIVER/RECEIVER SLLS187A – NOVEMBER 1994 – REVISED AUGUST 1995 PARAMETER MEASUREMENT INFORMATION 5V Rws 3V Input (see Note A and B) VDD 0V Input Output 51 Ω VSS GND RL VOH 90% Output CL 90% 10% 10% VOL tTHL tTLH GND Figure 1. Driver Transition Times Input + 51 Ω 0.5 V Input (see Note A and C) VDD 50% 50% – 0.5 V tPHL tPLH Output – CL 50% Output 50% VSS GND GND Figure 2. Receiver Propagation Delay Times 0.5 V Input (see Note A and C) VDD – 0.5 V Input + 51 Ω GND Output – CL VOH Output VOL 90% 90% 10% 10% tTLH VSS tTHL GND Figure 3. Receiver Transition Times NOTES: A. CL includes probe and jig capacitance. B. The input pulse is supplied by a generator having the following characteristics: tr ≤ 10 nS, tf < 10 nS, Zo = 50 Ω, PRR ≥ 5 kHz, duty cycle 50%, Vmax = 3 V, Vmin = 0 V. C. The input pulse is supplied by a generator having the following characteristics: tr ≤ 10 nS, tf < 10 nS, Zo = 50 Ω, PRR ≥ 5 kHz, duty cycle 50%, Vmax = 0.5 V, Vmin = – 0.5 V. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 SN75LBC784 QUADRUPLE RS-423-B DRIVER/RECEIVER SLLS187A – NOVEMBER 1994 – REVISED AUGUST 1995 PARAMETER MEASUREMENT INFORMATION 50% Input A 50% tPLH Output Y tPHL 50% 50% Figure 4. Skew Definition Times 500 Ω 250 mW 250 mW 500 Ω Vcm Vcm = – 7 to 7 V Figure 5. Receiver Input Balance Test 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. 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