Patent ID: 7023245

Claim:
A two-step band-pass charge sampling circuit comprising a first and second band-pass charge sampling circuit comprising: a first signal input and a second signal input for receiving a first and second end of a differential analog signal, respectively, in said first band-pass charge sampling circuit for producing signal samples at the signal output or output pair of said first band-pass charge sampling circuit with a first sample rate; a chopping circuit for chopping the signal from the first band-pass charge sampling circuit symmetrically in time at its signal output or output pair with the frequency of a clock signal equal to said first sample rate; a differential-out amplifier for amplifying the signal from the chopping circuit differentially at its signal output pair; wherein the first signal input and the second signal input of said second band-pass charge sampling circuit are connected to the signal output pair of said amplifier for producing signal samples at the signal output or output pair with a second sample rate.