Patent ID: 7898320

Claim:
A strobed bandgap reference circuit comprising: a bandgap reference circuit; a strobe circuit including an output storage device interconnected with the output of said bandgap reference circuit and a strobe control circuit for periodically powering up said bandgap reference circuit to charge said output storage device and powering down said bandgap reference circuit to conserve power; a substrate bandgap core having a differential output; a primary amplifier for receiving at its input said differential output and a feedback circuit responsive to said primary amplifier to drive to zero said differential output at its input; said primary amplifier having inherent offset and noise errors; a first storage device connected to a nulling input of said primary amplifier; an auxiliary amplifier having inherent offset and noise errors; a second storage device connected to a nulling input of said auxiliary amplifier; and a switching circuit for selectively, in a first mode, shorting the inputs of said auxiliary amplifier and connecting its output to said second storage device to develop a compensation voltage for nulling the noise and offset error of said auxiliary amplifier and in a second mode connecting the input of said nulled auxiliary amplifier in parallel with the input to said primary amplifier and connecting the output of said nulled auxiliary amplifier to said first storage device to develop a compensation voltage for nulling the noise and offset error of said primary amplifier.