DS96177 RS-485/RS-422 Differential Bus Repeater General Description DS96174 differential line drivers, DS96173 and DS96175 differential line receivers, or DS96176 differential bus transceivers. The DS96177 Differential Bus Repeater is a monolithic integrated device designed for one-way data communication on multipoint bus transmission lines. This device is designed for balanced transmission bus line applications and meets EIA Standard RS-485 and RS-422A. The device is designed to improve the performance of the data communication over long bus lines. The DS96177 has an active high Enable. The DS96177 features positive and negative current limiting and TRI-STATE ® outputs for the receiver and driver. The receiver features high input impedance, input hysteresis for increased noise immunity, and input sensitivity of 200 mV over a common mode input voltage range of −12V to +12V. The driver features thermal shutdown for protection from line fault conditions. Thermal shutdown is designed to occur at a junction temperature of approximately 160˚C. The driver is designed to drive current loads up to 60 mA maximum. The DS96177 is designed for optimum performance when used on transmission buses employing the DS96172 and n Meets EIA Standard RS-422A and RS-485 n Designed for multipoint transmission on long bus lines in noisy environments n TRI-STATE outputs n Bus voltage range −7.0V to +12V n Positive and negative current limiting n Driver output capability ± 60 mA max n Driver thermal shutdown protection n Receiver input high impedance n Receiver input sensitivity of ± 200 mV n Receiver input hysteresis of 50 mV typical n Operates from single 5.0V supply n Low power requirements Connection Diagram Function Table 8-Lead Dual-In-Line Package DS009644-1 Top View Order Number DS96177CN See NS Package Number N08E Features Differential Inputs Enable A–B E T Outputs Y VID ≥ 0.2V H H H L VID ≤ −0.2V H L L H X L Z Z Z Z Note: T is an output pin only, monitoring the BUS (RO). H = High Level L = Low Level X = Immaterial Z = High Impedance (off) TRI-STATE ® is a registered trademark of National Semiconductor Corporation. © 1999 National Semiconductor Corporation DS009644 www.national.com DS96177 RS-485/RS-422 Differential Bus Repeater October 1993 Absolute Maximum Ratings (Note 2) Recommended Operating Conditions If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (VCC) Storage Temperature Range Ceramic DIP −65˚C to +175˚C Molded DIP −65˚C to +150˚C Lead Temperature Ceramic DIP (Soldering, 60 sec.) 300˚C Molded DIP (Soldering, 10 sec.) 265˚C Maximum Power Dissipation (Note 1) at 25˚C Molded Package 930 mW Supply Voltage 7.0V Input Voltage 5.5V Min Typ Max Units 4.75 5.25 V 12 V ± 12 V 5.0 Voltage at any Bus Terminal (Separately or Common −7.0 Mode) (VI or VCM) Differential Input Voltage (VID) Output Current HIGH (IOH) Driver −60 mA −400 µA Driver 60 mA Receiver 16 Receiver Output Current LOW (IOL) Operating Temperature (TA) 0 25 70 ˚C Note 1: Derate molded DIP package 7.5 mW/˚C above 25˚C. Electrical Characteristics (Notes 3, 4) Over recommended temperature, common mode input voltage, and supply voltage ranges, unless otherwise specified Symbol Parameter Conditions Min Typ Max Units 0.8 V −1.5 V DRIVER SECTION VIH Input Voltage HIGH VIL Input Voltage LOW VIC Input Clamp Voltage |VOD1| Differential Output Voltage |VOD2| Differential Output Voltage ∆|VOD2| Change in Magnitude of Differential 2.0 II = −18 mA IO = 0 mA 6.0 RL = 100Ω, Figure 1 RL = 54Ω, Figure 1 and Figure 2 RL = 100Ω, Figure 1 VOC Common Mode Output Voltage (Note 6) RL = 54Ω Figure 1 and Figure 2 RL = 54Ω or 100Ω ∆|VOC| Change in Magnitude of Common Mode Figure 1 Output Voltage (Note 5) V 2.0 2.25 1.5 2.0 V V ± 0.2 V VCM = 0V 3.0 V ± 0.2 V ± 100 ± 200 µA 20 µA −100 µA Output Voltage (Note 5) IO Output Current with Power Off IOZ High Impedance State Output Current IIH Input Current HIGH IIL Input Current LOW IOS Short Circuit Output Current (Note 10) ICC Supply Current VCC = 0V, VO = −7.0V to +12V VO = −7.0V to +12V ± 50 VI = 2.7V VI = 0.5V VO = −7.0V −250 VO = 0V VO = VCC VO = 12V No Load µA −150 mA 150 250 Outputs Enabled 35 Outputs Disabled 40 mA RECEIVER SECTION VTH Differential Input VO = 2.7V, IO = −0.4 mA 0.2 V High Threshold Voltage VTL Differential Input Low VO = 0.5V, IO = 8.0 mA −0.2 V Threshold Voltage (Note 7) VT+−VT− Hysteresis (Note 8) VIH Enable Input Voltage HIGH VIL Enable Input Voltage LOW www.national.com VCM = 0V 50 mV 2.0 V 0.8 2 V Electrical Characteristics (Notes 3, 4) (Continued) Over recommended temperature, common mode input voltage, and supply voltage ranges, unless otherwise specified Symbol Parameter Conditions Min Typ Max Units RECEIVER SECTION VIC Enable Input Clamp Voltage VOH High Level Output Voltage VOL Low Level Output Voltage IOZ II II = −18 mA VID = 200 mV, IOH = −400 µA, Figure 3 VID = −200 mV, IOL = 8.0 mA Figure 3 IOL = 16 mA −1.5 V 0.45 Other Input = 0V Line Input Current (Note 9) −360 Enable Input Current HIGH IIL Enable Input Current LOW RI Input Resistance IOS Short Circuit Output Current (Note 10) ICC Supply Current (Total Package) No Load µA 20 VI = 12V VI = −7.0V 1.0 mA −0.8 VIH = 2.7V VIL = 0.4V IIH V 0.50 VO = 0.4V VO = 2.4V High-Impedance State Output V 2.7 20 µA −100 µA −85 mA Outputs Enabled 35 mA Outputs Disabled 40 12 kΩ −15 Drive Switching Characteristics VCC = 5.0V, TA = 25˚C Symbol Parameter tDD Differential Output Delay Time tTD Differential Output Transition Time tPLH Propagation Delay Time, Conditions RL = 60Ω, Figure 4 RL = 60Ω, Figure 4 RL = 27Ω, Figure 5 Min Typ Max Units 15 25 ns 15 25 ns 12 20 ns RL = 27Ω, Figure 5 12 20 ns RL = 110Ω, Figure 6 RL = 110Ω, Figure 7 RL = 110Ω, Figure 6 RL = 110Ω, Figure 7 25 45 ns 25 40 ns 20 25 ns 29 35 ns Low-to-High Level Output tPHL Propagation Delay Time, High-to-Low Level Output tPZH Output Enable Time to High Level tPZL Output Enable Time to Low Level tPHZ Output Disable Time from High Level tPLZ Output Disable Time from Low Level Receiver Switching Characteristics VCC = 5.0V, TA = 25˚C Symbol tPLH Parameter Propagation Delay Time, Low-to-High Level Output tPHL Conditions VID = 0V to 3.0V, CL = 15 pF, Figure 8 Propagation Delay Time, Min Typ Max Units 16 25 ns 16 25 ns 15 22 ns 15 22 ns 14 30 ns 24 40 ns High-to-Low Level Output tPZH Output Enable Time to High Level tPZL Output Enable Time to Low Level tPHZ Output Disable Time from High Level tPLZ Output Disable Time from Low Level CL = 15 pF, Figure 9 CL = 5.0 pF, Figure 9 Note 2: “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices should be operated at these limits. The tables of “Electrical Characteristics” provide conditions for actual device operation. Note 3: Unless otherwise specified Min/Max limits apply across the 0˚C to +70˚C range for the DS96177. All typicals are given for VCC = 5V and TA = 25˚C. Note 4: All currents into the device pins are positive; all currents out of the device pins are negative. All voltages are referenced to ground unless otherwise specified. Note 5: ∆|VOD| and ∆|VOC| are the changes in magnitude of VOD, VOC respectively, that occur when the input is changed from a high level to a low level. Note 6: In EIA Standards RS-422A and RS-485, VOC, which is the average of the two output voltages with respect to ground, is called output offset voltage, VOS. Note 7: The algebraic convention, when the less positive (more negative) limit is designated minimum, is used in this data sheet for common mode input voltage and threshold voltage levels only. 3 www.national.com Receiver Switching Characteristics (Continued) Note 8: Hysteresis is the difference between the positive-going input threshold voltage, VT+, and the negative going input threshold voltage, VT−. Note 9: Refer to EIA Standards RS-485 for exact conditions. Note 10: Only one output at a time should be shorted. Parameter Measurement Information DS009644-2 FIGURE 1. Driver VOD2 and VOC DS009644-4 FIGURE 2. Driver VOD2 with Varying Common Mode Voltage DS009644-3 FIGURE 3. Receiver VOH and VOL DS009644-5 DS009644-6 FIGURE 4. Driver Differential Output Delay and Transition Times DS009644-7 DS009644-8 FIGURE 5. Drive Propagation Times www.national.com 4 Parameter Measurement Information (Continued) DS009644-9 DS009644-10 FIGURE 6. Driver Enable and Disable Times (tPZH, tPHZ) DS009644-12 DS009644-11 FIGURE 7. Driver Enable and Disable Times (tPZL, tPLZ) DS009644-14 DS009644-13 FIGURE 8. Receiver Propagation Delay Times 5 www.national.com Parameter Measurement Information (Continued) DS009644-15 DS009644-16 DS009644-17 DS009644-18 DS009644-19 FIGURE 9. Receiver Enable and Disable Times Note 11: The input pulse is supplied by a generator having the following characteristics: PRR = 1.0 MHz, duty cycle ≈ 50%, tr ≤ 6.0 ns, tf ≤ 6.0 ns, ZO = 50Ω. Note 12: CL includes probe and stray capacitance. Note 13: DS96177 Enable is active high. Note 14: All diodes are 1N916 or equivalent. www.national.com 6 Typical Application DS009644-20 The line length should be terminated at both ends in its characteristic impedance. Stub lengths off the main line should be kept as short as possible. Repeater control logic not shown FIGURE 10. 7 www.national.com DS96177 RS-485/RS-422 Differential Bus Repeater Physical Dimensions inches (millimeters) unless otherwise noted Molded Dual-In-Line Package (N) Order Number DS96177CN NS Package Number N08E 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 is any component of a life support 1. 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