MC3448AP

BIDIRECTIONAL INSTRUMENTATION BUS (GPIB) TRANSCEIVER
This bidirectional bus transceiver is intended as the interface between TTL or MOS logic and the IEEE Standard Instrumentation Bus (488-1978, often referred to as GPIB). The required bus ter-mination is internally provided. Each driver/receiver pair forms the complete interface between the bus and an instrument. Either the driver or the receiver of each channel is enabled by its corresponding Send/Receive input with the disabled output of the pair forced to a high impedance state. An additional option allows the driver outputs to be oper-ated in an open collector(1) or active pull-up configuration. The receivers have input hysteresis to improve noise margin, and their input loading follows the bus standard specifications.

• Four Independent Driver/Receiver Pairs

• Three-State Outputs

• High Impedance Inputs

• Receiver Hysteresis — 600 mV (Typ)

• Fast Propagation Times — 15-20 ns (Typ)

• TTL Compatible Receiver Outputs

• Single + 5 Volt Supply

• Open Collector Driver Output Option()

• Power Up/Power Down Protection (No Invalid Information Transmitted to Bus)

• No Bus Loading When Power Is Removed From Device

• Terminations Provided: Termination Removed When Device is Unpowered