Session 15-2

A 85mV 40nW Process-Tolerant Subthreshold 8x8 FIR
Filter in 130nm Technology

 

Abstract

Subthreshold operation is limited by low performance and high susceptibility to process variation. We propose variation tolerant ultra-dynamic voltage scaling (UDVS), and as an example we present an 8x8 process-tolerant FIR filter, working in both superthreshold and subthreshold regions featuring adaptive beta-ratio modulation and integrated level converters. Measurements show that the filter works at 85mV consuming 40nW, and the proposed method can salvage circuits which potentially failed to operate due to variations.