A low VtCMOS implementation of an LPLV digital filter core for portable audio applications

A low power 32nd-order digital filter for portable audio applications has b een designed and implemented in a single threshold 1-V 0.5-mum CMOS process . The design is full custom, using a combination of conventional CMOS and p ass-transistor circuits, optimized for low energy consumption and small are a. The filter features up to 16 biquad sections with programmable coefficie nts and performs fixed-point computations with 16-bit resolution. The measu red average energy consumption of 330 pJ per biquad computation indicates t hat the implementation of complex digital signal professing in a single-thr eshold low-voltage process is a viable alternative to implementations in mu ltiple threshold processes.