INTERFACE CIRCUIT AND PROGRAMMABLE LOGIC ARRAY DEVICE

摘要

PURPOSE: To eliminate signal propagation delay and enable high-speed operation over a wide temperature range by providing the interface circuit, equipped with band gap generators which have a positive and a negative temperature coefficients between a PLA device and a TTL output buffer. CONSTITUTION: The logical output of the PLA device 10 is transmitted to a TTL output buffer 36 through the interface circuit 110. In the circuit 110, a high-level clamp circuit 30 sends out a current (i) decreasing with rising temperature according to a reference voltage VB1 with the positive temperature coefficient from the band gap 40 and a band gap generating circuit 42 sends a reference voltage VB2 with the negative temperature coefficient to a sensing circuit 26. The circuit 26 generates a current increasing with the rising temperature in response to an input relating to the current (i) and the voltage VB2 to generate and supply a driving current Ix which is large at low temperature and small at high temperature to the base of a phase divider transistor Q2 of a buffer 36.