Low power, low noise amplifier system

A low power, low noise amplifier system comprising:

• at least one amplifier having first and second differential input terminals, first and second differential output terminals and providing a differential output;
• first and second input capacitors interconnected with said first and second differential amplifier input terminals;
• first and second feedback circuits containing first and second feedback capacitors, respectively, interconnected with said differential input and output terminals;
• 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 at least one amplifier;
• an output chopper switch circuit for receiving and selectively, alternately swapping said differential output synchronously with said input chopper switch circuit;
• a low pass filter responsive to said swapped differential outputs for providing a low noise, low power amplification of said low frequency differential inputs;
• and
• an analog to digital converter coupled to said low pass filter output, said analog to digital converter having a sampling bandwidth that is greater than the bandwidth of said low pass filter.

A low power, low noise amplifier system comprising:

• at least one amplifier having first and second differential input terminals, first and second differential output terminals and providing a differential output;
• first and second input capacitors interconnected with said first and second differential amplifier input terminals;
• first and second feedback circuits containing first and second feedback capacitors, respectively, interconnected with said differential input and output terminals;
• 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 differential input terminals of said at least one amplifier;
• an output chopper switch circuit for receiving and selectively, alternately swapping said differential output synchronously with said input chopper switch circuit;
• a low pass filter responsive to said swapped differential outputs for providing a low noise, low power amplification of said low frequency differential inputs;
• and
• a common mode feedback and offset cancellation circuit for setting an input common mode level independently of output common mode levels of said at least one amplifier and compensating for amplifier offset of said at least one amplifier.