Pre-driver circuits for an output driver

Abstract

A disclosed pre-driver includes multiple signal generation stages and a switching bias circuit with a first switch and a second switch. The first switch and primary inverters in each of the stages all receive the same input signal. When the input signal transitions, the first switch turns on the bias circuit to supply a bias voltage to each of the stages. However, the primary inverters do not concurrently turn on. Instead, due to the bias voltage and some additional circuitry within each stage, the primary inverters turn on in sequence and slowly, thereby ensuring that pre-driver signals generated and output by the different stages, respectively, transition in sequence and at a relatively slow rate. Once the last pre-driver signal transitions, the second switch turns off the switching bias circuit. Optionally, a selected one of multiple bias voltages could be used in order to tune delay and transition times.