Off-chip process, voltage, temperature, compensation resistor sharing

摘要

A process, voltage, and temperature calibration system that shares a single calibration resistor among multiple calibration circuits. The use of single calibration resistor among several calibration circuits is accomplished through time division multiplexing. N-channel and P-channel field effect transistor calibration also share the same resistor. Turning on transistors in calibration circuits of the type not being calibrated creates a low impedance path from one terminal of the calibration resistor to a power supply. This biases the calibration resistor for the calibration circuit.