Low power 9 bit cyclic ADC

Overview

The ADC is a fully differential 9-bit cyclic ADC which utilizes 4-bit binary weighted array to obtain 9-bit resolution. Cyclic algorithm for the ADC conversion is used to reduce number of capacitors in the capacitor array and save layout area. The ADC is designed for suppression of the supply variation, even in the conversion cycle.

Key Features

  • The ADC conversion is divided into three phases. In each of the phases three bits are obtained; in Phase I the three most significant bits are obtained (MSBs), in Phase II the three middle bits and in Phase III the three least significant bits (LSBs). The voltage swing at the output of the operational amplifier is adaptive and it depends on the conversion phase, accounting for the drop of supply voltage during the conversion cycle. Operational amplifier has a built-in slew rate (SR) detection circuit which dynamically controls the amplifier current and optimizes power consumption and speed.

Benefits

  • Low power consumption, insensitivity to power supply variations

Block Diagram

Low power 9 bit cyclic ADC Block Diagram

Applications

  • Low power applications, low sampling rate, ADC, energy harvesting systems

Deliverables

  • Schematic and layout design(GDS) for chosen 180 nm technology

Technical Specifications

Foundry, Node
180 nm
Maturity
First Silicon
Availability
Q3/2016
UMC
Silicon Proven: 180nm
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Semiconductor IP