MC74F657A中文资料摩托罗拉数据手册PDF规格书

OCTAL BIDIRECTIONAL TRANSCEIVER WITH 8-BIT PARITY GENERATOR CHECKER (3-STATE OUTPUTS)

The MC74F657A and MC74F657B are Octal Bidirectional Transceivers with an 8-bit parity Generator/Checker and 3-state outputs.

The A and B options are faster versions of the F657 and contain eight non-inverting buffers with 3-state outputs and an 8-bit parity generator/checker. These devices are intended for bus-oriented applications. The buffers have a guaranteed current sinking capability of 24 mA at the A ports and 64 mA at the B ports. The Transmit/Receiver (T/R) input determines the direction of the data flow through the bidirectional transceivers. Transmit (active HIGH) enables data from A ports to B ports; Receive (active LOW) enables data from B ports to A ports.

• High-Impedance NPN Base Input for Reduced Loading (20 µA in HIGH and LOW States)

• Ideal in Applications Where High Output Drive and Light Bus Loading are Required (IIL is 20 µA versus Fast std of 600 µA)

• Combines F245 and F280A Functions in One Package

• 3-State Outputs

• B Outputs, PARITY, ERROR, Sink 64 mA and Source 15 mA

• 15 mA Source Current

• Input Diodes for Termination Effects

• Glitchless Outputs During Power Up and Power Down

• High Impedance Outputs During Power Off

• ESD Protection > 4000 Volts