Implementation of low-noise switched-capacitor integrators with small capacitors

A technique to reduce noise transfer functions (NTF) of switched-capacitor (SC) integrators without changing their signal transfer functions (STF) is proposed. The proposed technique based on a simple reconnection scheme of multiple sampling capacitors. It can be implemented into any SC integrators as long as they have a transfer delay. A design strategy is also given to reduce the effect of parasitic capacitors. An SC integrator with a small total capacitance and a low noise transfer gain based on the proposed technique is also proposed. For a given design example, the total capacitance and the simulated noise transfer gain of the proposed SC integrator are 37% and 90% less than the conventional one.