Patent ID: 7671672
Filing Date: 2010-03-02
Classification: H03F

Abstract:
1. An active circuit, comprising: a first chopper circuit that receives an input signal and a chopping signal of a frequency higher than a base band of the input signal, and that provides a modulated input signal; an amplifier that receives the modulated input signal and that provides an amplified signal resulting form amplifying the modulated input signal; and a second chopper circuit that receives the amplified signal and the chopping signal to provide an output signal; wherein the first chopper circuit and the second chopper circuit further comprise a first switch and a second switch configured to open and close according to a first clock signal, the first switch and the second switch configured to pass the input signal when the first clock signal is in a first state, the first chopper circuit and the second chopper circuit further comprising a third switch and a fourth switch configured to open and close according to a second clock signal, the third switch and the fourth switch configured to pass an inverted input signal when the second clock signal is in a second state.