A Time-Based Analog-to-Digital Converter Using a Multi-Phase Voltage-Controlled Oscillator

摘要

A time-based analog-to-digital converter (ADC) employinga multi-phase voltage-controlled oscillator (VCO) is presented. The VCO is based on a ring oscillator which converts analog input voltage to phase information. Digital output is produced by a phase quantizer which consists of a counter for coarse quantization and phase detector for fine quantization. Using this technique, an 8-bit 100Msamples/s ADC is designed and simulated. Impact of jitter and VCO linearity on the ADC performance is analyzed and verified.