A Very Low Voltage ۹th Order Linear Phase Baseband Switched Capacitor Filter (RESEARCH NOTE)

A very low voltage ۹th order linear phase baseband switched capacitor (SC) filter has been designed to be used as part of a cellular GSM (Global System Mobile) receiver. A Gaussian-to-۶dB filter of the order of seven is chosen and a second order function is added to reduce the group delay variations around. The filter uses a fully differential topology to increase the dynamic range and reduce the clock feed-through noise and the distortion due to low voltage amplifier. Using a chopper stabilization technique in opamp design reduces the flicker noise. In order to reduce the charge injection two methods of delayed clock phases and dummy switches are used. The filter is realized by cascading the biquad sections. The filter has been designed in a ۰.۳۵μm CMOS technology and simulated with Hspice using BSIM ۳V۳ model. The filter operates at ۲MHz sampling frequency and ۱MHz chopping frequency with a corner frequency of ۱۰۰KHz and ۷mW power consumption.

کلیدواژه ها:

Low Voltage Analog Circuit ، Baseband SC Filter