Patent ID: 7834611

Claim:
A bandgap reference generating circuit comprising: an operational amplifier configured to generate a bandgap reference voltage; and a gain controller configured to control a gain of the operational amplifier to have different values in a normal mode and a low power mode, respectively, wherein the operational amplifier comprises: a comparator configured to differentially compare first and second input voltages; and an amplifier configured to generate a reference voltage in response to an output signal of the comparator, wherein the gain controller includes a first control switching unit configured to control a current of the comparator to have different values in the normal mode and the low power mode, respectively, and wherein the first control switching unit comprises: a first MOS transistor configured to switch on the current of the comparator in the normal mode; and a second MOS transistor configured to switch on the current of the comparator in the low power mode, wherein the first MOS transistor has a larger channel width than the second MOS transistor.