OTA-based gray-code algorithmic ADC

Abstract

This paper presents a Gray-code algorithmic analog-to-digital converter (ADC). The proposed circuit comprises of OTAs, diodes, resistors, and voltage comparator to synthesize a triangular-like DC transfer characteristic and a digital output for an one-bit cell ADC. The design structure is simple and flexible. An N-bit resolution can be implemented by cascading the N proposed one-bit cells. Experimental results verifying the circuit performances are agreed with the theoretical values. © 2006 ICASE.