Algorithm and architecture of a 1V low power hearing instrument DSP

Abstract

This paper presents a 1 V digital signal processor used in the Danalogic hearing aid manufactured by GN Danavox. The processor is the first general purpose programmable used in behind-the-ear and in-the-ear hearing aid applications. It is integrated with memories, in a 0.5~ CMOS process with standard thresholds. At 2 MHz processing speed, the processor consumes 800pA from a single cell battery. Using a dual multiplyaccumulate architecture, the processor executes a 256 point block floating-point FFT in just 2900 instruction cycles.