S2I first-order incremental A/D converter

Abstract

An incremental analogue-to-digital converter (ADC), designed as part of the signal-conditioning circuitry of a pressure sensor interface, is presented. For technological compatibility, the switched-current (SI) technique has been used, which does not need a double polysilicon CMOS process. To reduce the influence of the no-idealities of this technique, a conversion algorithm with digital correction has been chosen and circuit enhancements have been sought. A first 1 μm CMOS prototype has been tested in the laboratory, and a resolution up to 9 bits has been obtained for a 1 MHz clock. © IEE, 1998.