A Low-Cost CMOS Integrated Dual-Mode Dual-Slope ADC with Synchronous Rectification Circuit for AC/DC Signal Measuring

A lost-cost CMOS integrated dual-mode dual-slope ADC with synchronous rectification circuit for AC/DC signal measuring is newly proposed. Instead of traditional full wave rectifier, an improved synchronous rectifier is implemented. To realize the simplified architecture, we use only one comparator, one OP, and switches. The advantage is that it could not only support wider bandwidth for AC signal measurements from 60 Hz to 100.2 kHz, but also provide DC signals' digitization. It could be realized by even fewer chip area where by this dual-mode dual-slope ADC is realized in a 0.25-um 1p5m CMOS technology with a chip area 710 times 630 mum
²
. Simulation results show that ADC achieves 8-bit resolution in DC mode and 7-bit resolution in AC mode with 100 kHz signal bandwidth. Total power consumption is 5 mW.