Advances in programmable pulse based mixed-signal processing VLSI

This paper describes a pulse based signal processing technique for VLSI implementation of fully programmable analogue arrays. A pulse width modulation signal representation and a basic Palmo analogue cell are introduced. The equivalence of the Palmo cell to a switched capacitor building block is demonstrated and the sources of harmonic distortion are discussed. VLSI results showing 1st, 2nd, 3rd order IIR filters and a 24th order FIR filter are presented. Improvements for a fully programmable analogue array currently under testing are discussed.