Reference voltage generation circuit

Abstract

A reference voltage generation circuit includes an operational amplifier for outputting a constant voltage in accordance with reference voltages respectively input to an inverting terminal of the operational amplifier and a non-inverting terminal of the operational amplifier, and a start-up circuit for waking up the operational amplifier when the start-up circuit is switched from an idle mode to an active mode. The start-up circuit includes a first-type transistor having a gate connected to an output of the operational amplifier, a source connected to a supply voltage, and a drain connected to resistors, to supply a constant reference current to the resistors in accordance with an output voltage from the operational amplifier, thereby generating a band-gap output voltage. The resistors are connected in parallel to a stage, from which the band-gap output voltage is output, in order to generate a band-gap output voltage of about 0.6V.

Dependencies are inferred from the claim text.