DS78C20/DS88C20 Dual CMOS Compatible Differential Line Receiver General Description Features The DS78C20 and DS88C20 are high performance, dual differential, CMOS compatible line receivers for both balanced and unbalanced digital data transmission. The inputs are compatible with EIA and Federal Standards. Input specifications meet or exceed those of the popular DS7820/DS8820 line receiver, and the pinout is identical. A response pin is provided for controlling sensitivity to input noise spikes with an external capacitor. Each receiver includes a 180Ω terminating resistor, which may be used optionally on twisted pair lines. The DS78C20 is specified over a −55˚C to +125˚C operating temperature range, and the DS88C20 over a 0˚C to +70˚C range. n Meets requirements of EIA Standards RS-232-C RS-422 and RS-423, and Federal Standards 1020 and 1030 n Input voltage range of ± 15V (differential or common-mode) n Separate strobe input for each receiver n 1⁄2 VCC strobe threshold for CMOS compatibility n 5k typical input impedance n 50 mV input hysteresis n 200 mV input threshold n Operation voltage range = 4.5V to 15V n DS7830/DS8830 recommended driver Connection Diagram Dual-In-Line Package DS005798-1 Top View Order Number DS88C20N See NS Package Numbers N14A For Complete Military Product Specifications, refer to the appropriate SMD or MDS. Order Number DS78C20J/883 See NS Package Number J14A © 1998 National Semiconductor Corporation DS005798 www.national.com DS78C20/DS88C20 Dual CMOS Compatible Differential Line Receiver May 1998 Absolute Maximum Ratings (Note 2) Lead Temperature (Soldering, 4 seconds) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Operating Conditions Supply Voltage Common-Mode Voltage Differential Input Voltage Strobe Voltage Output Sink Current Maximum Power Dissipation (Note 1) at 25˚C Cavity Package Molded Package Storage Temperature Range 18V ± 25V ± 25V 18V 50 mA Supply Voltage (VCC) Temperature (TA) DS78C20 DS88C20 Common-Mode Voltage (VCM) 260˚C Min 4.5 Max 15 Units V −55 0 −15 +125 +70 +15 ˚C ˚C V Note 1: Derate cavity package 9.1 mW/˚C; derate molded package 10.2 mW/˚C above 25˚C. 1364 mW 1280 mW −65˚C to +150˚C Electrical Characteristics (Notes 3, 4) Symbol VTH Parameter 0.2 Voltage VOUT ≥ V CC −1.2V IOUT = 1.6 mA, VOUT ≤ 0.5V −15V ≤ VCM ≤ 15V 0.06 0.3 V −10V ≤ VCM ≤ 10V −0.08 −0.2 V −15V ≤ VCM ≤ 15V −0.08 −0.3 Line Termination Resistance Data Input Current (Unterminated) Input Balance −15V ≤ V CM ≤ 15V TA = 25˚C 5 100 VCM = 10V VCM = 0V VCM = −10V IOUT = 200 µA, VOUT ≥ VCC −1.2V, R S = 500Ω, VOH Logical “1” Output Voltage VOL Logical “0” Output Voltage ICC Power Supply Current −7V ≤ VCM ≤ 7V IOUT = −200 µA, VDIFF = 1V IOUT = 1.6 mA, VDIFF = −1V VCC−1.2 3.1 mA −0.5 mA −2 −3.1 mA 0.1 0.4 V −0.1 −0.4 V VCC−0.75 V 0.25 0.5 V mA 15 30 mA (Both Receivers) VSTROBE = 15V, VDIFF = 3V VCC = 15V 15 100 µA −0.5 −100 µA VSTROBE = 0V, VDIFF = −3V VCC = 15V Logical “1” Strobe Input IOUT = 1.6 mA, VOL ≤ 0.5V VCC = 5V VCC = 10V VCC = 15V VCC = 5V Voltage www.national.com 2 0 15 Logical “0” Strobe Input Current Output Short-Circuit Current Ω 8 IIN(0) IOS 300 VCC = 5.5V VCC = 15V Logical “1” Strobe Input Current Logical “0” Strobe Input V kΩ 15V ≤ VCM ≤ −15V, VDIFF = −0.5V IIN(1) Voltage 180 V −7V ≤ VCM ≤ 7V (Note 6) IOUT = 1.6 mA, VOUT ≤ 0.5V, RS = 500Ω, (Note 6) VIL Max Units 0.06 RT VIH Typ −10V ≤ VCM ≤ 10V Input Resistance VTHB Min IOUT = −200 µA, RIN IIND Conditions Differential Threshold IOUT = −200 µA, VOH = VCC −1.2V V OUT = 0V, VCC VCC = 10V VCC = 15V = 15V, VSTROBE = 0V, (Note 5) 2 3.5 2.5 8.0 5.0 V 12.5 7.5 V −5 V 2.5 1.5 V 5.0 2.0 V 7.5 2.5 V −20 −40 mA Switching Characteristics VCC = 5V, TA = 25˚C Symbol Parameter tpd0(D) Differential Input to “0” Output tpd1(D) Differential Input to “1” Output tpd0(S) Strobe Input to “0” Output tpd1(S) Strobe Input to “1” Output Conditions CL = 50 pF CL = 50 pF Min CL = 50 pF CL = 50 pF Typ Max 60 100 Units ns 100 150 ns 30 70 ns 100 150 ns Note 2: “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. Except for “Operating Temperature Range” they are not meant to imply that the devices should be operated at these limits. The table of “Electrical Characteristics” provides conditions for actual device operation. Note 3: Unless otherwise specified min/max limits apply across the −55˚C to +125˚C temperature range for the DS78C20 and across the 0˚C to +70˚C range for the DS88C20. All typical values are for TA = 25˚C, VCC = 5V and VCM = 0V. Note 4: All currents into device pins shown as positive, out of device pins as negative, all voltages referenced to ground unless otherwise noted. All values shown as max or min on absolute value basis. Note 5: Only one output at a time should be shorted. Note 6: Refer to EIA-RS-422 for exact conditions. Typical Applications RS-422/RS-423 Application DS005798-2 Note 7: (Optional internal termination resistor.) a) Capacitor in series with internal line termination resistor, terminates the line and saves termination power. Exact value depends on line length. b) Pin 1 connected to pin 2; terminates the line. c) Pin 2 open; no internal line termination. d) Transmission line may be terminated elsewhere or not at all. Note 8: Optional to control response time. Note 9: VCC 4.5V to 15V for the DS78C20. For further information on line drivers and line receivers, refer to applicaton notes AN-22, AN-83 and AN-108. RS-232-C Application with Hysteresis DS005798-4 DS005798-3 For signals which require fail-safe or have slow rise and fall times, use R1 and D1 as shown above. Otherwise, the positive input (pin 3 or 11) may be connected to ground. 3 www.national.com Typical Applications (Continued) VCC R1 ± 5% 5V 4,3 kΩ 10V 15 kΩ 15V 24 kΩ AC Test Circuit DS005798-5 tr = tf = ≤ 10 ns PRR = 1 MHz Note 10: Includes probe and jig capacitance Switching Time Waveforms DS005798-6 www.national.com 4 Physical Dimensions inches (millimeters) unless otherwise noted Ceramic Dual-In-Line Package (J) Order Number DS78C20J/883 NS Package Number J14A Molded Dual-In-Line Package (N) Order Number DS88C20N NS Package Number N14A 5 www.national.com DS78C20/DS88C20 Dual CMOS Compatible Differential Line Receiver LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 2. A critical component in any component of a life support 1. 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