Power and area efficient circular-memory switched-capacitor FIR baseband filter for WCDMA/GSM

This paper presents a new two-sections architecture of a low power switched capacitor (SC) finite impulse response (FIR) filter suitable for base-band signal processing in WCDMA and in GSM standards. The low power operation is possible due to several optimization techniques like division of the filter into shorter sections and by use a low power control logic block. The important advantage is possibility of using filter with the same coefficients in both standard modes. The only difference is in the sampling frequency (fS). Our proposed programmable 24-taps FIR filter dissipates 4.5 mW of power from the 1.8 V power supply for fS = 20 MHz. Controlling the supply voltage allows for control of both the fS and the power dissipation.