DS3695A/DS3695AT/DS3696A Multipoint RS485/RS422 Transceivers General Description Features The DS3695A and DS3696A are high speed differential TRI-STATE ® bus/line transceivers designed to meet the requirements of EIA standard RS485 with extended common mode range (+12V to −7V), for multipoint data transmission. In addition they are compatible with requirements of RS-422. The driver and receiver outputs feature TRI-STATE capability. The driver outputs remain in TRI-STATE over the entire common mode range of +12V to −7V. Bus faults that cause excessive power dissipation within the device trigger a thermal shutdown circuit, which forces the driver outputs into the high impedance state. The DS3696A provides an output pin (TS) which reports the thermal shutdown of the device. TS is an “open collector” pin with an internal 10 kΩ pull-up resistor. This allows the TS outputs of several devices to be wire OR-ed. Both AC and DC specifications are guaranteed over the 0˚C to 70˚C temperature and 4.75V to 5.25V supply voltage range. n Meets EIA standard RS485 for multipoint bus transmission and is compatible with RS-422 n 10 ns driver propagation delays (typical) n Single +5V supply n −7V to +12V bus common mode range permits ± 7V ground difference between devices on the bus n Thermal shutdown protection n High impedance to bus with driver in TRI-STATE or with power off, over the entire common mode range allows the unused devices on the bus to be powered down n Combined impedance of a driver output and receiver input is less than one RS485 unit load, allowing up to 32 transceivers on the bus n 70 mV typical receiver hysteresis n Available in SOIC packaging Connection and Logic Diagram Molded Package, Small Outline (M) DS005272-1 Top View DS005272-2 TS was LF (Line Fault) on previous datasheets, TS goes low upon thermal shutdown. Top View Order Number DS3695AM, DS3695ATM or DS3696AM See NS Package Number M08A TRI-STATE ® is a registered trademark of National Semiconductor Corporation. © 1998 National Semiconductor Corporation DS005272 www.national.com DS3695A/DS3695AT/DS3696A Multipoint RS485/RS422 Transceivers February 1996 Absolute Maximum Ratings (Note 1) Lead Temp. (Soldering 4 seconds) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage, VCC Control Input Voltages Driver Input Voltage Driver Output Voltages Receiver Input Voltages Receiver Output Voltage Continuous Power Dissipation 25˚C M Package Storage Temp. Range 260˚C Recommended Operating Conditions 7V 7V 7V +15V/−10V +15V/−10V 5.5V Supply Voltage, VCC Bus Voltage Operating Free Air Temp. (TA) Commercial (DS3695AM) Industrial (DS3695ATM) Commercial (DS3696AM) 630 mW (Note 4) −65˚C to +150˚C Min 4.75 −7 Max 5.25 +12 Units V V 0 −40 0 +70 +85 +70 ˚C ˚C ˚C Electrical Characteristics (Notes 2, 3) 0˚C ≤ TA ≤ 70˚C, 4.75V < VCC < 5.25V unless otherwise specified Symbol VOD1 Parameter Conditions Differential Driver Output Min Typ IO = 0 Voltage (Unloaded) VOD2 ∆VOD Differential Driver Output R = 50Ω; (RS-422) (Note 5) Voltage (with Load) R = 27Ω; (RS-485) Max Units 5 V 2 V 1.5 V Change in Magnitude of Driver Differential Output Voltage For 0.2 V 3.0 V 0.2 V 0.8 V Complementary Output States VOC Driver Common Mode Output Voltage ∆|VOC| Change in Magnitude of Driver R = 27Ω Common Mode Output Voltage For Complementary Output States VIH Input High Voltage VIL Input Low Voltage VCL Input Clamp Voltage IIL Input Low Current 2 V DI, DE, RE , RE /DE IIH Input High Current IIN Input Current VTH Differential Input Threshold DO/RI, DO /RI RI, RI IIN = −18 mA −1.5 V VIL = 0.4V −200 µA VIH = 2.4V 20 µA VIN = 12V +1.0 mA DE or RE /DE = 0V VIN = −7V −0.8 mA VCC = 0V or 5.25V −7V ≤ VCM ≤ +12V −0.2 Voltage for Receiver +0.2 V ∆VTH Receiver Input Hysteresis VCM = 0V VOH Receiver Output High Voltage IOH = −400 µA VOL Output Low Voltage IOL = 16 mA (Note 5) 0.5 V IOL = 8 mA 0.45 V IOZR OFF-State (High Impedance) VCC = Max Output Current at Receiver 0.4V ≤ VO ≤ 2.4V ± 20 µA RIN Receiver Input Resistance −7V ≤ VCM ≤ +12V ICC Supply Current No Load Driver Outputs Enabled 42 60 mA (Note 5) Driver Outputs Disabled 27 40 mA IOSD Driver Short-Circuit VO = −7V (Note 5) −250 mA Output Current VO = +12V (Note 5) +250 mA Receiver Short-Circuit VO = 0V −85 mA RO TS IOSR 70 mV 2.4 V 12 −15 kΩ Output Current Note 1: “Absolute maximum ratings” are those beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the device should be operated at these limits. The tables of “Electrical Characteristics” provide conditions for actual device operation. www.national.com 2 Electrical Characteristics (Notes 2, 3) (Continued) Note 2: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified. Note 3: All typicals are given for VCC = 5V and TA = 25˚C. Note 4: Derate linearly at 6.5 mW/˚C to 337 mW at 70˚C. Note 5: All limits for which Note 5 is applied must be derated by 10% for DS3695AT. Other parameters remain the same for this extended temperature range device (−40˚C ≤ TA ≤ +85˚C). Switching Characteristics 0˚C ≤ TA ≤ 70˚C, 4.75V < VCC < 5.25V unless otherwise specified (Note 3) Receiver Switching Characteristics (Figures 1, 2 and Figure 3) Min Typ Max Units tPLH Symbol CL = 15 pF Conditions 15 28 42 ns tPHL S1 and S2 15 28 42 |tPLH–tPHL| Closed 0 3 ns ns tPLZ CL = 15 pF, S2 Open 5 29 35 ns tPHZ CL = 15 pF, S1 Open 5 12 16 ns tPZL CL = 15 pF, S2 Open 7 15 28 ns tPZH CL = 15 pF, S1 Open 7 15 20 ns Min Typ Max Units Driver Switching Characteristics Symbol Conditions SINGLE ENDED CHARACTERISTICS (Figures 4, 5 and Figure 7) tPLH RLDIFF = 60Ω 9 15 22 ns tPHL CL1 = CL2 = 100 pF 9 15 22 ns 0 2 8 ns 7 15 30 ns tSKEW|tPLH–tPHL| tPLZ CL = 15 pF, S2 Open tPHZ CL = 15 pF, S1 Open 7 15 30 ns tPZL CL = 100 pF, S2 Open 30 35 50 ns tPZH CL = 100 pF, S1 Open 30 35 50 ns 6 10 18 ns DIFFERENTIAL SWITCHING CHARACTERISTICS (Figure 7) tr, tf RLDIFF = 60Ω CL1 = CL2 = 100 pF AC Test Circuits and Switching Waveforms DS005272-6 FIGURE 1. Receiver Propagation Delay Test Circuit 3 www.national.com AC Test Circuits and Switching Waveforms (Continued) DS005272-7 Differential input voltage may be realized by grounding RI and pulsing RI between +2.5V and −2.5V FIGURE 2. Receiver Input-to-Output Propagation Delay Timing DS005272-8 FIGURE 3. Receiver Enable/Disable Propagation Delay Timing DS005272-10 DS005272-9 Unless otherwise specified the switches are closed. FIGURE 4. Driver Propagation Delay Test Circuits DS005272-11 tPLH and tPHL are measured to the respective 50% points. tSKEW is the difference between propagation delays of the complementary outputs. FIGURE 5. Driver Input-to-Output Propagation Delay Timing (Single-Ended) www.national.com 4 AC Test Circuits and Switching Waveforms (Continued) DS005272-12 FIGURE 6. Driver Enable/Disable Propagation Delay Timing DS005272-13 FIGURE 7. Driver Differential Transition Timing Function Tables DS3695A/DS3696A Transmitting Inputs Line Outputs RE DE DI Condition DO DO TS * (DS3696A Only) X 1 1 No Fault 0 1 H X 1 0 No Fault 1 0 H X 0 X X Z Z H X 1 X Fault Z Z L DS3695A/DS3696A Receiving Inputs Output RE DE RI–RI RO TS * (DS3696A Only) 0 0 ≥+0.2V 1 H 0 0 ≤−0.2V 0 H 0 0 Inputs Open** 1 H 1 0 X Z H X — Don’t care condition Z — High impedance state Fault — Improper line conditions causing excessive power dissipation in the driver, such as shorts or bus contention situations * TS is an “open collector” output with an on-chip 10 kΩ pull-up resistor. ** This is a fail safe condition 5 www.national.com Typical Application DS005272-18 Repeater control logic not shown. See AN-702. www.national.com 6 7 DS3695A/DS3695AT/DS3696A Multipoint RS485/RS422 Transceivers Physical Dimensions inches (millimeters) unless otherwise noted Molded SOIC Package (M) Order Number DS3695AM, DS3695ATM or DS3696AM NS Package Number M08A 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. Life support devices or systems are devices or sysdevice or system whose failure to perform can be reatems which, (a) are intended for surgical implant into sonably expected to cause the failure of the life support the body, or (b) support or sustain life, and whose faildevice or system, or to affect its safety or effectiveness. ure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 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