COMPARATOR WITH SMOOTH START-UP FOR HIGH FREQUENCIES

摘要

A comparator has a simple high frequency signal path from input to output formed by two differentially connected transistors (Q1, Q2) with an output transistor (Q8, Q3) connected to each. A current control circuit maintains a constant total current flowing through the differentially connected transistors (Q1, Q2). The ratio of currents flowing through the differentially connected transistors (Q1, Q2) is initially set by a control circuit (I1, I2), so that the output of the comparator is predictable when powered up. The control circuit then gradually releases control, so that there is a smooth transfer to control by a reference signal input to the comparator.