TIMING SIGNAL GENERATOR CIRCUIT FOR USE IN SIGNAL WAVEFORM MEASUREMENT SYSTEM FOR MEASURING MULTI-CHANNEL ON-CHIP SIGNALS FLOWING ON VLSI

摘要

A timing signal generator circuit includes a DA converter converting an input digital value into an analog voltage, and a VT converter converting the analog voltage into a corresponding delay time. The DA converter includes a current source circuit, which supplies a current (n×Is) (“n” is a number corresponding to the input digital value) selected from a total supply current (N×Is) as a current Iout to the resistors, and supplies the remaining current (N−n)×Is as a current Idump to the resistors, outputs a voltage across the resistors as an analog voltage Vdac, and outputs a voltage across the resistor as a reset voltage Vreset. The VT converter charges the integration capacitor with a constant current from the constant current source by using the reset voltage as an initial voltage, and outputs a timing signal when the integral voltage exceeds the analog voltage.