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| Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers General Description The HWD481, HWD483, HWD485, HWD487-HWD491, and HWD1487 are low-power transceivers for RS-485 and RS422 communication. Each part contains one driver and one receiver. The HWD483, HWD487, HWD488, and HWD489 feature reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, thus allowing error-free data transmission up to 250kbps. The driver slew rates of the HWD481, HWD485, HWD490, HWD491, and HWD1487 are not limited, allowing them to transmit up to 2.5Mbps. These transceivers draw between 120A and 500A of supply current when unloaded or fully loaded with disabled drivers. Additionally, the HWD481, HWD483, and HWD487 have a low-current shutdown mode in which they consume only 0.1A. All parts operate from a single 5V supply. Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit. The HWD487 and HWD1487 feature quarter-unit-load receiver input impedance, allowing up to 128 HWD487/ HWD1487 transceivers on the bus. Full-duplex communications are obtained using the HWD488-HWD491, while the HWD481, HWD483, HWD485, HWD487, and HWD1487 are designed for half-duplex applications. __Next Generation Device Features For Fault-Tolerant Applications HWD3430: 80V Fault-Protected, Fail-Safe, 1/4 Unit Load, +3.3V, RS-485 Transceiver HWD3440E-HWD3444E: 15kV ESD-Protected, 60V Fault-Protected, 10Mbps, Fail-Safe, RS-485/J1708 Transceivers For Space-Constrained Applications HWD3460-HWD3464: +5V, Fail-Safe, 20Mbps, Profibus RS-485/RS-422 Transceivers HWD3362: +3.3V, High-Speed, RS-485/RS-422 Transceiver in a SOT23 Package HWD3280E-HWD3284E: 15kV ESD-Protected, 52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422, True Fail-Safe Receivers HWD3293/HWD3294/HWD3295: 20Mbps, +3.3V, SOT23, RS-855/RS-422 Transmitters For Multiple Transceiver Applications HWD3030E-HWD3033E: 15kV ESD-Protected, +3.3V, Quad RS-422 Transmitters For Fail-Safe Applications HWD3080-HWD3089: Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers For Low-Voltage Applications HWD3483E/HWD3485E/HWD3486E/HWD3488E/ HWD3490E/HWD3491E: +3.3V Powered, 15kV ESD-Protected, 12Mbps, Slew-Rate-Limited, True RS-485/RS-422 Transceivers Ordering Information appears at end of data sheet. ________________________Applications Low-Power RS-485 Transceivers Low-Power RS-422 Transceivers Level Translators Transceivers for EMI-Sensitive Applications Industrial-Control Local Area Networks ______________________________________________________________Selection Table PART NUMBER HWD481 HWD483 HWD485 HWD487 HWD488 HWD489 HWD490 HWD491 HWD1487 HALF/FULL DUPLEX Half Half Half Half Full Full Full Full Half DATA RATE (Mbps) 2.5 0.25 2.5 0.25 0.25 0.25 2.5 2.5 2.5 SLEW-RATE LIMITED No Yes No Yes Yes Yes No No No LOW-POWER SHUTDOWN Yes Yes No Yes No No No No No RECEIVER/ DRIVER ENABLE Yes Yes Yes Yes No Yes No Yes Yes QUIESCENT CURRENT (A) 300 120 300 120 120 120 300 300 230 NUMBER OF TRANSMITTERS ON BUS 32 32 32 128 32 32 32 32 128 PIN COUNT 8 8 8 8 8 14 8 14 8 1 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC) .............................................................12V Control Input Voltage (RE, DE)...................-0.5V to (VCC + 0.5V) Driver Input Voltage (DI).............................-0.5V to (VCC + 0.5V) Driver Output Voltage (A, B)...................................-8V to +12.5V Receiver Input Voltage (A, B).................................-8V to +12.5V Receiver Output Voltage (RO).....................-0.5V to (VCC +0.5V) Continuous Power Dissipation (TA = +70C) 8-Pin Plastic DIP (derate 9.09mW/C above +70C) ....727mW 14-Pin Plastic DIP (derate 10.00mW/C above +70C) ..800mW 8-Pin SO (derate 5.88mW/C above +70C).................471mW 14-Pin SO (derate 8.33mW/C above +70C)...............667mW 8-Pin MAX (derate 4.1mW/C above +70C) ..............830mW 8-Pin CERDIP (derate 8.00mW/C above +70C).........640mW 14-Pin CERDIP (derate 9.09mW/C above +70C).......727mW Operating Temperature Ranges HWD4_ _C_ _/HWD1487C_ A ...............................0C to +70C HWD4_ _E_ _/HWD1487E_ A .............................-40C to +85C HWD4_ _MJ_/HWD1487MJA ...........................-55C to +125C Storage Temperature Range .............................-65C to +160C Lead Temperature (soldering, 10sec) .............................+300C DC ELECTRICAL CHARACTERISTICS (VCC = 5V 5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER Differential Driver Output (no load) Differential Driver Output (with load) Change in Magnitude of Driver Differential Output Voltage for Complementary Output States Driver Common-Mode Output Voltage Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States Input High Voltage Input Low Voltage Input Current SYMBOL VOD1 VOD2 R = 50 (RS-422) R = 27 (RS-485), Figure 4 R = 27 or 50, Figure 4 R = 27 or 50, Figure 4 R = 27 or 50, Figure 4 DE, DI, RE DE, DI, RE DE, DI, RE DE = 0V; VCC = 0V or 5.25V, all devices except HWD487/HWD1487 HWD 487/HWD1487, DE = 0V, VCC = 0V or 5.25V Receiver Differential Threshold Voltage Receiver Input Hysteresis Receiver Output High Voltage Receiver Output Low Voltage Three-State (high impedance) Output Current at Receiver VTH VTH VOH VOL IOZR -7V VCM 12V VCM = 0V IO = -4mA, VID = 200mV IO = 4mA, VID = -200mV 0.4V VO 2.4V -7V VCM 12V, all devices except HWD487/HWD1487 Receiver Input Resistance RIN -7V VCM 12V, HWD487/HWD1487 48 k 12 3.5 0.4 1 VIN = 12V VIN = -7V VIN = 12V VIN = -7V -0.2 70 2.0 0.8 2 1.0 mA -0.8 0.25 -0.2 0.2 mA V mV V V A k 2 1.5 5 0.2 3 0.2 CONDITIONS MIN TYP MAX 5 UNITS V V VOD VOC VOD VIH VIL IIN1 V V V V V A Input Current (A, B) IIN2 2 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers DC ELECTRICAL CHARACTERISTICS (continued) (VCC = 5V 5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS HWD488/HWD489, DE, DI, RE = 0V or VCC HWD490/HWD491, DE, DI, RE = 0V or VCC No-Load Supply Current (Note 3) ICC HWD481/HWD485, RE = 0V or VCC HWD1487, RE = 0V or VCC HWD483/HWD487, RE = 0V or VCC Supply Current in Shutdown Driver Short-Circuit Current, VO = High Driver Short-Circuit Current, VO = Low Receiver Short-Circuit Current ISHDN IOSD1 IOSD2 IOSR DE = VCC DE = 0V DE = VCC DE = 0V DE = 5V HWD483 HWD487 MIN TYP 120 300 500 300 300 230 350 250 120 0.1 35 35 7 MAX 250 500 900 500 500 400 650 400 250 10 250 250 95 A UNITS DE = 0V HWD481/483/487, DE = 0V, RE = VCC -7V VO 12V (Note 4) -7V VO 12V (Note 4) 0V VO VCC A mA mA mA SWITCHING CHARACTERISTICS--HWD481/HWD485, HWD490/HWD491, HWD1487 (VCC = 5V 5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER Driver Input to Output Driver Output Skew to Output Driver Rise or Fall Time Driver Enable to Output High Driver Enable to Output Low Driver Disable Time from Low Driver Disable Time from High Receiver Input to Output SYMBOL CONDITIONS tPLH Figures 6 and 8, RDIFF = 54, CL1 = CL2 = 100pF tPHL tSKEW Figures 6 and 8, RDIFF = 54, CL1 = CL2 = 100pF HWD481, HWD485, HWD1487 Figures 6 and 8, RDIFF = 54, tR, tF HWD490C/E, HWD491C/E CL1 = CL2 = 100pF HWD490M, HWD491M tZH Figures 7 and 9, CL = 100pF, S2 closed tZL Figures 7 and 9, CL = 100pF, S1 closed tLZ Figures 7 and 9, CL = 15pF, S1 closed tHZ Figures 7 and 9, CL = 15pF, S2 closed Figures 6 and 10, HWD481, HWD485, HWD1487 tPLH, tPHL RDIFF = 54, HWD490C/E, HWD491C/E CL1 = CL2 = 100pF HWD490M, HWD491M tSKD tZL tZH tLZ tHZ fMAX tSHDN Figures 6 and 10, RDIFF = 54, CL1 = CL2 = 100pF Figures 5 and 11, CRL = 15pF, S1 closed Figures 5 and 11, CRL = 15pF, S2 closed Figures 5 and 11, CRL = 15pF, S1 closed Figures 5 and 11, CRL = 15pF, S2 closed HWD481 (Note 5) 2.5 50 MIN 10 10 3 5 3 TYP 30 30 5 15 15 15 40 40 40 40 90 90 90 13 20 20 20 20 200 50 50 50 50 600 MAX 60 60 10 40 25 40 70 70 70 70 200 150 200 UNITS ns ns ns ns ns ns ns ns 20 20 20 | tPLH - tPHL | Differential Receiver Skew Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable Time from Low Receiver Disable Time from High Maximum Data Rate Time to Shutdown ns ns ns ns ns Mbps ns 3 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers SWITCHING CHARACTERISTICS--HWD481/HWD485, HWD490/HWD491, HWD1487 (continued) (VCC = 5V 5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS Figures 7 and 9, CL = 100pF, S2 closed Figures 7 and 9, CL = 100pF, S1 closed Figures 5 and 11, CL = 15pF, S2 closed, A - B = 2V Figures 5 and 11, CL = 15pF, S1 closed, B - A = 2V MIN TYP 40 40 300 300 MAX 100 100 1000 1000 UNITS ns ns ns ns Driver Enable from Shutdown to tZH(SHDN) Output High (HWD481) Driver Enable from Shutdown to tZL(SHDN) Output Low (HWD481) Receiver Enable from Shutdown tZH(SHDN) to Output High (HWD481) Receiver Enable from Shutdown tZL(SHDN) to Output Low (HWD481) SWITCHING CHARACTERISTICS--HWD483, HWD487/HWD488/HWD489 (VCC = 5V 5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER Driver Input to Output Driver Output Skew to Output Driver Rise or Fall Time Driver Enable to Output High Driver Enable to Output Low Driver Disable Time from Low Driver Disable Time from High Receiver Input to Output SYMBOL tPLH tPHL tSKEW tR, tF tZH tZL tLZ tHZ tPLH tPHL tSKD tZL tZH tLZ tHZ fMAX tSHDN tZH(SHDN) tZL(SHDN) tZH(SHDN) tZL(SHDN) CONDITIONS Figures 6 and 8, RDIFF = 54, CL1 = CL2 = 100pF Figures 6 and 8, RDIFF = 54, CL1 = CL2 = 100pF Figures 6 and 8, RDIFF = 54, CL1 = CL2 = 100pF Figures 7 and 9, CL = 100pF, S2 closed Figures 7 and 9, CL = 100pF, S1 closed Figures 7 and 9, CL = 15pF, S1 closed Figures 7 and 9, CL = 15pF, S2 closed Figures 6 and 10, RDIFF = 54, CL1 = CL2 = 100pF Figures 6 and 10, RDIFF = 54, CL1 = CL2 = 100pF Figures 5 and 11, CRL = 15pF, S1 closed Figures 5 and 11, CRL = 15pF, S2 closed Figures 5 and 11, CRL = 15pF, S1 closed Figures 5 and 11, CRL = 15pF, S2 closed tPLH, tPHL < 50% of data period HWD483/HWD487 (Note 5) HWD483/HWD487, Figures 7 and 9, CL = 100pF, S2 closed HWD483/HWD487, Figures 7 and 9, CL = 100pF, S1 closed HWD483/HWD487, Figures 5 and 11, CL = 15pF, S2 closed HWD483/HWD487, Figures 5 and 11, CL = 15pF, S1 closed 250 50 200 600 2000 2000 2500 2500 250 250 250 300 300 250 250 100 20 20 20 20 50 50 50 50 MIN 250 250 TYP 800 800 100 MAX 2000 2000 800 2000 2000 2000 3000 3000 2000 2000 UNITS ns ns ns ns ns ns ns ns ns ns ns ns ns kbps ns ns ns ns ns I tPLH - tPHL I Differential Receiver Skew Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable Time from Low Receiver Disable Time from High Maximum Data Rate Time to Shutdown Driver Enable from Shutdown to Output High Driver Enable from Shutdown to Output Low Receiver Enable from Shutdown to Output High Receiver Enable from Shutdown to Output Low 4 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers NOTES FOR ELECTRICAL/SWITCHING CHARACTERISTICS Note 1: 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 2: All typical specifications are given for VCC = 5V and TA = +25C. Note 3: Supply current specification is valid for loaded transmitters when DE = 0V. Note 4: Applies to peak current. See Typical Operating Characteristics. Note 5: The HWD481/HWD483/HWD487 are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 50ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section. __________________________________________Typical Operating Characteristics (VCC = 5V, TA = +25C, unless otherwise noted.) OUTPUT CURRENT vs. RECEIVER OUTPUT LOW VOLTAGE 45 40 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 35 30 25 20 15 10 5 0 0 0.5 1.0 1.5 2.0 2.5 OUTPUT LOW VOLTAGE (V) -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 OUTPUT HIGH VOLTAGE (V) OUTPUT HIGH VOLTAGE (V) OUTPUT CURRENT vs. RECEIVER OUTPUT HIGH VOLTAGE 4.8 4.6 4.4 4.2 4.0 3.8 3.6 3.4 3.2 3.0 RECEIVER OUTPUT HIGH VOLTAGE vs. TEMPERATURE IRO = 8mA -50 -25 0 25 50 75 100 125 TEMPERATURE (C) RECEIVER OUTPUT LOW VOLTAGE vs. TEMPERATURE 0.9 0.8 OUTPUT LOW VOLTAGE (V) 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -50 -25 0 25 50 75 100 125 TEMPERATURE (C) IRO = 8mA OUTPUT CURRENT (mA) 90 80 70 60 50 40 30 20 10 0 0 DRIVER OUTPUT CURRENT vs. DIFFERENTIAL OUTPUT VOLTAGE 2.4 DIFFERENTIAL OUTPUT VOLTAGE (V) 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 DIFFERENTIAL OUTPUT VOLTAGE (V) DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs. TEMPERATURE R = 54 -50 -25 0 25 50 75 100 125 TEMPERATURE (C) 5 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers ____________________________Typical Operating Characteristics (continued) (VCC = 5V, TA = +25C, unless otherwise noted.) OUTPUT CURRENT vs. DRIVER OUTPUT LOW VOLTAGE 140 120 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 100 80 60 40 20 0 0 2 4 6 8 10 12 OUTPUT LOW VOLTAGE (V) -120 -100 -80 -60 -40 -20 0 OUTPUT CURRENT vs. DRIVER OUTPUT HIGH VOLTAGE 600 HWD481/HWD485/HWD490/HWD491 SUPPLY CURRENT vs. TEMPERATURE HWD481/HWD485; DE = V , RE = X CC 500 SUPPLY CURRENT (A) 400 300 200 100 HWD481; DE = 0, RE = VCC HWD485; DE = 0, RE = X, HWD481; DE = RE = 0 HWD490/HWD491; DE = RE = X 0 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 45 -50 -25 0 25 50 75 100 125 OUTPUT HIGH VOLTAGE (V) TEMPERATURE (C) HWD483/HWD487-HWD489 SUPPLY CURRENT vs. TEMPERATURE 600 500 SUPPLY CURRENT (A) 400 300 HWD487; DE = VCC, RE = X HWD483; DE = VCC, RE = X HWD1487 SUPPLY CURRENT vs. TEMPERATURE 600 500 SUPPLY CURRENT (A) 400 300 200 HWD1487; DE = 0V, RE = X HWD1487; DE = VCC, RE = X 200 100 HWD483/HWD487; DE = RE = 0, HWD488/HWD489; DE = RE = X 100 HWD483/HWD487; DE = 0, RE = V CC 0 -50 -25 0 25 50 75 100 125 TEMPERATURE (C) 0 -60 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (C) 6 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers ______________________________________________________________Pin Description PIN HWD481/HWD483/ HWD485/HWD487/ HWD1487 DIP/SO 1 2 MAX 3 4 HWD488/ HWD490 DIP/SO 2 -- MAX 4 -- HWD489/ HWD491 DIP/SO 2 3 RO RE Receiver Output: If A > B by 200mV, RO will be high; If A < B by 200mV, RO will be low. Receiver Output Enable. RO is enabled when RE is low; RO is high impedance when RE is high. Driver Output Enable. The driver outputs, Y and Z, are enabled by bringing DE high. They are high impedance when DE is low. If the driver outputs are enabled, the parts function as line drivers. While they are high impedance, they function as line receivers if RE is low. Driver Input. A low on DI forces output Y low and output Z high. Similarly, a high on DI forces output Y high and output Z low. Ground Noninverting Driver Output Inverting Driver Output Noninverting Receiver Input and Noninverting Driver Output Noninverting Receiver Input Inverting Receiver Input and Inverting Driver Output Inverting Receiver Input Positive Supply: 4.75V VCC 5.25V No Connect--not internally connected NAME NAME FUNCTION FUNCTION 3 5 -- -- 4 DE 4 5 -- -- 6 -- 7 -- 8 -- TOP VIEW 6 7 -- -- 8 -- 1 -- 2 -- 3 4 5 6 -- 8 -- 7 1 -- 5 6 7 8 -- 2 -- 1 3 -- 5 6, 7 9 10 -- 12 -- 11 14 1, 8, 13 DI GND Y Z A A B B VCC N.C. RO 1 R 8 7 6 VCC B A GND RO 1 R 8 VCC 7B Rt 6 A 5 GND RE 2 DE 3 DI 4 D HWD481 HWD483 HWD485 HWD487 HWD1487 B Rt A R DE D DI 5 DIP/SO B VCC RO 1 2 3 8 A GND DI DE RE 2 DE 3 DI 4 D RO RE 4 HWD481 HWD483 HWD485 HWD487 HWD1487 MAX 7 6 5 RE NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM DIAGRAMS REFER TO PINS A AND B WHEN DE IS HIGH. TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE. Figure 1. HWD481/HWD483/HWD485/HWD487/HWD1487 Pin Configuration and Typical Operating Circuit 7 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers TOP VIEW VCC 1 RO 2 DI 3 GND 4 D R 8 7 6 5 A B Z Y DI 3 5Y VCC 1 VCC HWD488 HWD490 D Rt 6Z R RO DIP/SO 8A B A VCC RO 1 2 3 4 8 Z Y GND DI 4 GND NOTE: TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE. GND RO 2 R Rt 7 B D DI HWD488 HWD490 7 6 5 MAX Figure 2. HWD488/HWD490 Pin Configuration and Typical Operating Circuit TOP VIEW DE 4 VCC 14 9 Y Rt 10 Z 12 A Rt 11 B VCC RE HWD489 HWD491 N.C. RO RE DE DI GND GND 1 2 3 4 5 6 7 D R 14 V CC 13 N.C. 12 A 11 B 10 Z 9 8 Y N.C. NC 1, 8, 13 3 RO 2 DI 5 D R RO R D DI DIP/SO 6, 7 RE GND GND DE Figure 3. HWD489/HWD491 Pin Configuration and Typical Operating Circuit __________Applications Information The HWD481/HWD483/HWD485/HWD487-HWD491 and HWD1487 are low-power transceivers for RS-485 and RS422 communications. The HWD481, HWD485, HWD490, HWD491, and HWD1487 can transmit and receive at data rates up to 2.5Mbps, while the HWD483, HWD487, HWD488, and HWD489 are specified for data rates up to 250kbps. The HWD488-HWD491 are full-duplex transceivers while the HWD481, HWD483, HWD485, HWD487, and HWD1487 are half-duplex. In addition, Driver Enable (DE) and Receiver Enable (RE) pins are included on the HWD481, HWD483, HWD485, HWD487, HWD489, HWD491, and HWD1487. When disabled, the driver and receiver outputs are high impedance. HWD487/HWD1487: 128 Transceivers on the Bus The 48k, 1/4-unit-load receiver input impedance of the HWD487 and HWD1487 allows up to 128 transceivers on a bus, compared to the 1-unit load (12k input impedance) of standard RS-485 drivers (32 transceivers maximum). Any combination of HWD487/ HWD1487 and other RS-485 transceivers with a total of 32 unit loads or less can be put on the bus. The HWD481/HWD483/HWD485 and HWD488-HWD491 have standard 12k Receiver Input impedance. 8 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers _________________________________________________________________Test Circuits Y R VOD R Z VOC S2 TEST POINT RECEIVER OUTPUT CRL 15pF 1k VCC S1 1k Figure 4. Driver DC Test Load Figure 5. Receiver Timing Test Load 3V DE DI Y VID Z CL1 RDIFF A RO B RE 500 OUTPUT UNDER TEST CL S1 VCC S2 CL2 Figure 6. Driver/Receiver Timing Test Circuit Figure 7. Driver Timing Test Load HWD483/HWD487/HWD488/HWD489: Reduced EMI and Reflections The HWD483 and HWD487-HWD489 are slew-rate limited, minimizing EMI and reducing reflections caused by improperly terminated cables. Figure 12 shows the driver output waveform and its Fourier analysis of a 150kHz signal transmitted by a HWD481, HWD485, HWD490, HWD491, or HWD1487. High-frequency har- monics with large amplitudes are evident. Figure 13 shows the same information displayed for a HWD483, HWD487, HWD488, or HWD489 transmitting under the same conditions. Figure 13's high-frequency harmonics have much lower amplitudes, and the potential for EMI is significantly reduced. 9 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers _______________________________________________________Switching Waveforms 3V DI 0V 1.5V tPLH tPHL 1.5V 1/2 VO tZL(SHDN), tZL Y, Z VO Y 1/2 VO VO VDIFF 0V -VO 10% tR tSKEW = | tPLH - tPHL | VDIFF = V (Y) - V (Z) 90% 90% tF 10% VOL Y, Z 2.3V 0V tZH(SHDN), tZH tHZ 2.3V OUTPUT NORMALLY LOW OUTPUT NORMALLY HIGH VOH -0.5V VOL +0.5V tLZ DE 0V 3V 1.5V 1.5V Z Figure 8. Driver Propagation Delays Figure 9. Driver Enable and Disable Times (except HWD488 and HWD490) 3V RE 0V RO VOH VOL VID -VID 0V 1.5V tPHL INPUT OUTPUT tPLH 0V RO 0V tZH(SHDN), tZH tHZ 1.5V 1.5V VCC RO tZL(SHDN), tZL tLZ VOL + 0.5V 1.5V 1.5V 1.5V OUTPUT NORMALLY LOW OUTPUT NORMALLY HIGH A-B VOH - 0.5V Figure 10. Receiver Propagation Delays Figure 11. Receiver Enable and Disable Times (except HWD488 and HWD490) _________________Function Tables (HWD481/HWD483/HWD485/HWD487/HWD1487) Table 1. Transmitting INPUTS RE X X 0 1 DE 1 1 0 0 DI 1 0 X X Z 0 1 High-Z High-Z* OUTPUTS Y 1 0 High-Z High-Z* RE 0 0 0 1 Table 2. Receiving INPUTS DE 0 0 0 0 A-B > +0.2V < -0.2V Inputs open X OUTPUT RO 1 0 1 High-Z* X = Don't care High-Z = High impedance * Shutdown mode for HWD481/HWD483/HWD487 X = Don't care High-Z = High impedance * Shutdown mode for HWD481/HWD483/HWD487 10 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 10dB/div 10dB/div 0Hz 500kHz/div 5MHz 0Hz 500kHz/div 5MHz Figure 12. Driver Output Waveform and FFT Plot of HWD481/ HWD485/HWD490/HWD491/HWD1487 Transmitting a 150kHz Signal Figure 13. Driver Output Waveform and FFT Plot of HWD483/ HWD487-HWD489 Transmitting a 150kHz Signal Low-Power Shutdown Mode (HWD481/HWD483/HWD487) A low-power shutdown mode is initiated by bringing both RE high and DE low. The devices will not shut down unless both the driver and receiver are disabled. In shutdown, the devices typically draw only 0.1A of supply current. RE and DE may be driven simultaneously; the parts are guaranteed not to enter shutdown if RE is high and DE is low for less than 50ns. If the inputs are in this state for at least 600ns, the parts are guaranteed to enter shutdown. For the HWD481, HWD483, and HWD487, the tZH and tZL enable times assume the part was not in the lowpower shutdown state (the HWD485/HWD488-HWD491 and HWD1487 can not be shut down). The tZH(SHDN) and tZL(SHDN) enable times assume the parts were shut down (see Electrical Characteristics). It takes the drivers and receivers longer to become enabled from the low-power shutdown state (tZH(SHDN), tZL(SHDN)) than from the operating mode -- -- (tZH, tZL). (The parts are in operating mode if the RE , DE inputs equal a logical 0,1 or 1,1 or 0, 0.) Driver Output Protection Excessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range (see Typical Operating Characteristics). In addition, a thermal shutdown circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively. Propagation Delay Many digital encoding schemes depend on the difference between the driver and receiver propagation delay times. Typical propagation delays are shown in Figures 15-18 using Figure 14's test circuit. The difference in receiver delay times, | tPLH - tPHL |, is typically under 13ns for the HWD481, HWD485, HWD490, HWD491, and HWD1487 and is typically less than 100ns for the HWD483 and HWD487-HWD489. The driver skew times are typically 5ns (10ns max) for the HWD481, HWD485, HWD490, HWD491, and HWD1487, and are typically 100ns (800ns max) for the HWD483 and HWD487-HWD489. 11 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 100pF Z TTL IN tR, tF < 6ns D Y R = 54 A B R RECEIVER OUT 100pF Figure 14. Receiver Propagation Delay Test Circuit A 500mV/div VCC = 5V TA = +25C B 500mV/div VCC = 5V TA = +25C B RO A 2V/div 2V/div RO 20ns/div 20ns/div Figure 15. HWD481/HWD485/HWD490/HWD491/HWD487 Receiver tPHL Figure 16. HWD481/HWD485/HWD490/HWD491/HWD1487 Receiver tPLH A 500mV/div VCC = 5V TA = +25C B 500mV/div VCC = 5V TA = +25C B RO 2V/div A 2V/div RO 400ns/div 400ns/div Figure 17. HWD483, HWD487-HWD489 Receiver tPHL Figure 18. HWD483, HWD487-HWD489 Receiver tPLH 12 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers Line Length vs. Data Rate The RS-485/RS-422 standard covers line lengths up to 4000 feet. For line lengths greater than 4000 feet, see Figure 23. Figures 19 and 20 show the system differential voltage for the parts driving 4000 feet of 26AWG twisted-pair wire at 110kHz into 120 loads. Figures 21 and 22 show typical network applications circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet, as shown in Figure 23. To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possible. The slew-rate-limited HWD483 and HWD487-HWD489 are more tolerant of imperfect termination. Typical Applications The HWD481, HWD483, HWD485, HWD487-HWD491, and HWD1487 transceivers are designed for bidirectional data communications on multipoint bus transmission lines. DI 5V 0V DI 5V 0V 1V VY-VZ 0V -1V VY-VZ 1V 0V -1V RO 5V 0V RO 5V 0V 2s/div 2s/div Figure 19. HWD481/HWD485/HWD490/HWD491/HWD1487 System Differential Voltage at 110kHz Driving 4000ft of Cable Figure 20. HWD483, HWD487-HWD489 System Differential Voltage at 110kHz Driving 4000ft of Cable 120 DI B 120 B DE D DE RO RE A B A B A A D DI R R RO RE R HWD481 HWD483 HWD485 HWD487 HWD1487 D D R DI DE RO RE DI DE RO RE Figure 21. HWD481/HWD483/HWD485/HWD487/HWD1487 Typical Half-Duplex RS-485 Network 13 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers A RO RE DE Z DI Y 120 120 Z DE B 120 120 Y Z B A Y Z B A A RE RO R B D DI D Y R R D D R HWD489 HWD491 DE RE RO DI DE RE RO DI NOTE: RE AND DE ON HWD489/HWD491 ONLY. Figure 22. HWD488-HWD491 Full-Duplex RS-485 Network Isolated RS-485 HWD488-HWD491 A RO RE DE DI For isolated RS-485 applications, see the HWD253 and HWD1480 data sheets. R 120 B DATA IN Z D 120 Y DATA OUT NOTE: RE AND DE ON HWD489/HWD491 ONLY. Figure 23. Line Repeater for HWD488-HWD491 14 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers _______________Ordering Information PART HWD481CPA HWD481CSA HWD481CUA HWD481C/D HWD481EPA HWD481ESA HWD481MJA HWD483CPA HWD483CSA HWD483CUA HWD483C/D HWD483EPA HWD483ESA HWD483MJA HWD485CPA HWD485CSA HWD485CUA HWD485C/D HWD485EPA HWD485ESA HWD485MJA HWD487CPA HWD487CSA HWD487CUA HWD487C/D HWD487EPA HWD487ESA HWD487MJA HWD488CPA HWD488CSA HWD488CUA HWD488C/D HWD488EPA HWD488ESA HWD488MJA HWD489CPD HWD489CSD HWD489C/D HWD489EPD HWD489ESD HWD489MJD TEMP. RANGE 0C to +70C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 0C to +70C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 0C to +70C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 0C to +70C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 0C to +70C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C PIN-PACKAGE 8 Plastic DIP 8 SO 8 MAX Dice* 8 Plastic DIP 8 SO 8 CERDIP 8 Plastic DIP 8 SO 8 MAX Dice* 8 Plastic DIP 8 SO 8 CERDIP 8 Plastic DIP 8 SO 8 MAX Dice* 8 Plastic DIP 8 SO 8 CERDIP 8 Plastic DIP 8 SO 8 MAX Dice* 8 Plastic DIP 8 SO 8 CERDIP 8 Plastic DIP 8 SO 8 MAX Dice* 8 Plastic DIP 8 SO 8 CERDIP 14 Plastic DIP 14 SO Dice* 14 Plastic DIP 14 SO 14 CERDIP __Ordering Information (continued) PART HWD490CPA HWD490CSA HWD490CUA HWD490C/D HWD490EPA HWD490ESA HWD490MJA HWD491CPD HWD491CSD HWD491C/D HWD491EPD HWD491ESD HWD491MJD HWD1487CPA HWD1487CSA HWD1487CUA HWD1487C/D HWD1487EPA HWD1487ESA HWD1487MJA TEMP. RANGE 0C to +70C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 0C to +70C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C PIN-PACKAGE 8 Plastic DIP 8 SO 8 MAX Dice* 8 Plastic DIP 8 SO 8 CERDIP 14 Plastic DIP 14 SO Dice* 14 Plastic DIP 14 SO 14 CERDIP 8 Plastic DIP 8 SO 8 MAX Dice* 8 Plastic DIP 8 SO 8 CERDIP * Contact factory for dice specifications. _________________Chip Topographies HWD481/HWD483/HWD485/HWD487/HWD1487 V CC RO RE DE DI GND 0.080" (2.032mm) A N.C. N.C. B 0.054" (1.372mm) 15 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers _____________________________________________Chip Topographies (continued) HWD488/HWD490 V CC RO N.C. N.C. DI GND 0.080" (2.032mm) Y A B 0.054" Z (1.372mm) RO RE DE DI GND 0.080" (2.032mm) Y HWD489/HWD491 V CC A B Z 0.054" (1.372mm) TRANSISTOR COUNT: 248 SUBSTRATE CONNECTED TO GND 16 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers Package Information INCHES DIM A A1 B C e E H L MAX MIN 0.069 0.053 0.010 0.004 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.016 0.050 MILLIMETERS MAX MIN 1.35 1.75 0.10 0.25 0.35 0.49 0.19 0.25 1.27 BSC 3.80 4.00 5.80 6.20 0.40 1.27 N E H VARIATIONS: 1 INCHES MILLIMETERS MIN 4.80 8.55 9.80 MAX 5.00 8.75 10.00 N MS012 8 AA 14 AB 16 AC TOP VIEW DIM D D D MIN 0.189 0.337 0.386 MAX 0.197 0.344 0.394 D A e B A1 L C 0-8 FRONT VIEW SIDE VIEW TITLE: PACKAGE OUTLINE, .150" SOIC 17 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers Package Information (continued) . 8 4X S 8 INCHES DIM A A1 A2 b c D e E H MIN 0.002 0.030 MAX 0.043 0.006 0.037 MILLIMETERS MAX MIN 0.05 0.75 1.10 0.15 0.95 y 0.500.1 0.60.1 E H 1 0.60.1 1 D L S BOTTOM VIEW 0.014 0.010 0.007 0.005 0.120 0.116 0.0256 BSC 0.120 0.116 0.198 0.188 0.026 0.016 0 6 0.0207 BSC 0.25 0.36 0.13 0.18 2.95 3.05 0.65 BSC 2.95 3.05 4.78 5.03 0.41 0.66 0 6 0.5250 BSC TOP VIEW A2 A1 A e c b L SIDE VIEW FRONT VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 8L uMAX/uSOP 18 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers Package Information (continued) implied. (c) 200 19 Chengdu Sino Microelectronics System Co.,Ltd (Http://www.csmsc.com) Headquarters of CSMSC: Address: 2nd floor, Building D, Science & Technology Industrial Park, 11 Gaopeng Avenue, Chengdu High-Tech Zone,Chengdu City, Sichuan Province, P.R.China PC: 610041 Tel: +86-28-8517-7737 Fax: +86-28-8517-5097 Beijing Office: Address: Room 505, No. 6 Building, Zijin Garden, 68 Wanquanhe Rd., Haidian District, Beijing, P.R.China PC: 100000 Tel: +86-10-8265-8662 Fax: +86-10-8265-86 Shenzhen Office: Address: Room 1015, Building B, Zhongshen Garden, Caitian Rd, Futian District, Shenzhen, P.R.China PC: 518000 Tel : +86-775-8299-5149 +86-775-8299-5147 +86-775-8299-6144 Fax: +86-775-8299-6142 |
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