ADM485E AD [Analog Devices], ADM485E Datasheet
ADM485E
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ADM485E Summary of contents
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... ADM487E and ADM1487E have a 1/4 unit load receiver input impedance that allows up to 128 transceivers on a bus, whereas the ADM485E allows transceivers on a bus. Because only one driver is enabled at any time, the output of a disabled or power-down driver is three-stated to avoid overloading the bus. ...
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... ADM485E/ADM487E/ADM1487E TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 Functional Block Diagram .............................................................. 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Timing Specifications .................................................................. 4 Absolute Maximum Ratings............................................................ 6 ESD Caution.................................................................................. 6 Pin Configuration and Function Descriptions............................. 7 REVISION HISTORY 1/07—Revision 0: Initial Version Typical Performance Characteristics ..............................................8 Test Circuits and Switching Characteristics................................ 11 Theory of Operation ...................................................................... 13 Circuit Description .................................................................... 13 Applications Information ...
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... V < V < 2 −7 V < V < +12 V (ADM485E) CM −7 V< V < +12 V (ADM487E/ADM1487E (ADM485E (ADM485E (ADM1487E (ADM1487E (ADM487E (ADM487E) ...
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... TIMING SPECIFICATIONS ± 5 unless otherwise noted MIN MAX Table 3. ADM485E/ADM1487E Parameter DRIVER Input to Output Output Skew to Output Rise/Fall Time Enable Time to High Level Enable Time to Low Level Disable Time from Low Level Disable Time from High Level ...
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... The ADM487E is put into shutdown mode by bringing the RE high and the DE low. If the inputs are in this state for less than 50 ns, the parts are guaranteed not to 1 enter shutdown. If the inputs are in this state for at least 600 ns, the ADM487E is guaranteed to enter shutdown. ADM485E/ADM487E/ADM1487E Symbol Min ...
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... ADM485E/ADM487E/ADM1487E ABSOLUTE MAXIMUM RATINGS T = 25°C, unless otherwise noted. A Table 5. Parameter V to GND CC Digital I/O Voltage (DE, RE) Driver Input Voltage (DI) Receiver Output Voltage (RO) Driver Output/Receiver Input Voltage (A, B) Operating Temperature Range Storage Temperature Range θ Thermal Impedance JA SOIC-8 Lead Temperature Soldering (10 sec) Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device ...
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... GND Ground Connection (0 V Noninverting Receiver Input A/Driver Output Inverting Receiver Input B/Driver Output Power Supply (5 V ± 5%). CC ADM485E/ADM487E/ADM1487E ADM485E/ CC ADM487E ADM1487E TOP VIEW (Not to Scale) DI GND 4 5 Figure 2. Pin Configuration ...
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... ADM485E/ADM487E/ADM1487E TYPICAL PERFORMANCE CHARACTERISTICS 0.5 1.0 1.5 OUTPUT LOW VOLTAGE (V) Figure 3. Output Current vs. Receiver Output Low Voltage –30 –25 –20 –15 –10 –5 0 1.5 2.0 2.5 3.0 3.5 OUTPUT HIGH VOLTAGE (V) Figure 4. Output Current vs. Receiver Output High Voltage 4.5 4.4 4.3 4.2 I 4.1 4.0 3.9 –40 – TEMPERATURE (°C) Figure 5 ...
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... OUTPUT HIGH VOLTAGE (V) Figure 10. Output Current vs. Driver Output High Voltage 600 500 400 300 AND 200 AND 100 0 –40 – TEMPERATURE (°C) Figure 11. ADM485E/ADM1487E Supply Current vs. Temperature 600 500 400 300 200 100 – ...
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... PLH CH1 5.00V CH2 500mV M20ns CH3 500mV T 60.80% Figure 16. ADM485E/ADM1487E Receiver CH1 2.80V CH1 CH3 A CH1 2.70V PHL Rev Page 5.00V CH2 500mV M20ns A CH1 500mV T 60.80% Figure 17. ADM485E/ADM1487E Receiver t PLH 2.70V ...
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... OUT 500Ω 1. DHZ , DHZ DZH DZH(SHDN) Rev Page ADM485E/ADM487E/ADM1487E 50Ω DZL DZL(SHDN) DLZ 2. DZL RECEIVER B OUTPUT ATE Figure 23. Receiver Propagation Delay Test Circuit ...
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... ADM485E/ADM487E/ADM1487E RZH, RZH(SHDN CLOSED S3 = +1.5V RE +1.5V +0.5V RO +1.5V S3 1kΩ –1. 15pF GENERATOR 50Ω S1 OPEN S2 CLOSED S3 = +1.5V + RZL +1. OPEN + RHZ Figure 25. Receiver Enable and Disable Times Rev Page CLOSED S2 OPEN S3 = – ...
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... The input impedance on the ADM485E is 12 kΩ, allowing transceivers on the differential bus. The ADM487E/ ADM1487E are 48 kΩ, allowing up to 128 transceivers on the differential bus ...
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... ADM485E/ADM487E/ADM1487E ESD Testing Two coupling methods are used for ESD testing: contact discharge and air-gap discharge. Contact discharge calls for a direct connection to the unit being tested; air-gap discharge uses a higher test voltage but does not make direct contact with the unit under test. With air discharge, the discharge gun is moved toward the unit under test, developing an arc across the air gap ...
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... Only one driver is enabled at a time, but the RS-485 standard contains additional specifications to guarantee device safety in the event of line contention. ADM485E/ADM487E/ADM1487E CABLE AND DATA RATE The transmission line of choice for RS-485 communications is a twisted pair. A twisted pair cable can cancel common-mode ...
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... ADM485E/ADM487E/ADM1487E OUTLINE DIMENSIONS 0.25 (0.0098) 0.10 (0.0040) COPLANARITY ORDERING GUIDE Model Temperature Range 1 ADM485EARZ –40°C to +85°C 1 ADM485EARZ-REEL7 –40°C to +85°C ADM487EARZ 1 –40°C to +85°C 1 ADM487EARZ-REEL7 –40°C to +85°C 1 ADM1487EARZ –40°C to +85°C 1 ADM1487EARZ-REEL7 –40°C to +85° Pb-free part ...