Patent ID: 7795960

Claim:
A low power, low noise amplifier system comprising: a first amplifier having first and second differential input terminals, and first and second differential output terminals for providing a differential output of said first amplifier; first and second input capacitors interconnected with said first and second differential input terminals of said first amplifier; first and second feedback circuits containing first and second feedback capacitors, respectively, interconnected with said differential input and output terminals of said first amplifier; an input chopper switch circuit for receiving a low frequency differential input and selectively, alternately swapping said low frequency differential input through said first and second input capacitors to the first and second differential input terminals of said first amplifier; an output chopper switch circuit for receiving and selectively, alternately swapping said differential output of said first amplifier synchronously with said input chopper switch circuit; a low pass filter responsive to said swapped differential output for providing a low noise, low power amplification of said low frequency differential input; a second amplifier having third and fourth differential input terminals, and third and fourth differential output terminals for providing a differential output of said second amplifier; third and fourth input capacitors interconnected with said third and fourth differential input terminals; and third and fourth feedback circuits containing third and fourth feedback capacitors, respectively, interconnected with said differential input and output terminals of said second amplifier.