CIRCUITS FOR PREVENTING UNWANTED OUTPUT TRANSIENTS IN AMPLIFIERS DURING POWER-UP

摘要

The present invention reduces certain unwanted transients in an output stage (350) by sensing the power supply (Vdd) and disabling the output stage output devices (30) in correlation with the sensing of an invalid bias. In preferred embodiments, the bias is measured at a node that is the last bias node (N1) to reach a steady state during power up or power glitches. This ensures that all portions of the output stage (350) are being provided a valid bias prior to enabling the output devices (30) of the output stage (350). By enabling the output devices (30) only after a valid bias is present, signals generated by the output devices (30) are based upon valid operation of the output stage (350).