SN75ALS170A
三路差动总线收发器
The SN75ALS170 and triple differential bus transceivers are monolithic integrated circuits designed for bidirectional data communication on multipoint bus transmission lines. It is designed for balanced transmission lines and the driver meets ANSI Standards EIA/A-422-B and RS-485 and both the driver and receiver meet ITU Recommendation V.11. The SN75ALS170A is designed for FAST-20 SCSI and can transmit or receive data pulses as short as 30 ns with a maximum skew of 5 ns.
The SN75ALS170 and SN75ALS170A operate from a single 5-V power supply. The drivers and receivers have active-high and active-low enables, respectively, which are internally connected together to function as a direction control. The driver differential outputs and the receiver differential inputs are connected internally to form differential input/output I/O bus ports that are designed to offer minimum loading to the bus when the driver is disabled or VCC = 0. These ports feature wide positive and negative common-mode voltage ranges making the device suitable for party-line applications.
The SN75ALS170 and the SN75ALS170A are characterized for operation from 0°C to 70°C.
H = high level, L = low level, ? = indeterminate,
X = irrelevant, Z = high impedance off
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- Three Bidirectional Transceivers
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- Driver Meets or Exceeds ANSI Standard EIA/TIA-422-B and RS-485 and ITU Recommendation V.11
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- Two Skew Limits Available
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- Designed to Operate Up to 20 Million Data Transfers per Second FAST-20 SCSI
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- High-Speed Advanced Low-Power Schottky Circuitry
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- Designed for Multipoint Transmission on Long Bus Lines in Noisy Environments
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- Wide Positive and Negative Input/Output Bus Voltage Ranges
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- Driver Output Capacity...±60 mA
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- Thermal Shutdown Protection
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- Driver Positive- and Negative-Current Limiting
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- Receiver Input Impedances...12 k Min
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- Receiver Input Sensitivity...±300 mV Max
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- Receiver Input Hysteresis...60 mV Typ
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- Operate From a Single 5-V Supply
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- Glitch-Free Power-Up and Power-Down Protection
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- Feature Independent Direction Controls for Each Channel