Fast bandgap reference circuit for use in a low power supply a/d booster

Abstract

A bandgap reference circuit includes a current generation circuit connected to a voltage generation circuit connected to a smart clamping circuit, and a discharge circuit connected to the current generation circuit and the voltage generation circuit. The discharge circuit initially discharges a potential in the current and voltage generation circuits to improve repeatability. A start circuit within the current generation circuit then initializes the reference output at about the supply voltage to improve the speed and settling time of the output signal. The current generation circuit sources a current to the voltage generation circuit that translates the current having a positive function of temperature +Tinto a reference voltage. The smart clamping circuit further generates a clamping voltage having a negative function of temperature −Tand a load resistance. The clamping voltage and the load resistance are applied across the reference voltage quickly reducing the reference voltage particularly at high temperatures and during start-up to a final level, thereby producing a fast and stable reference voltage.