A new successive approximation architecture for low-power low-cost CMOS A/D converter

A new 6-bit 250 MS/s analog-to-digital converter (ADC) is proposed for low-power low-cost CMOS integrated systems. This design is based on an improved successive approximation ADC with a mixed-mode subtracter that minimizes the overall power consumption and system complexity. The experimental results indicate that this ADC works up to 250 MS/s with power consumption less than 30 mW at 3.3 V. Moreover, the operating voltage is scaled down to 0.8 V using a slight adjustment. The ADC occupies only 0.1 mm² with the TSMC 0.35-μm single poly quadruple metal (SPQM) CMOS technology. This design is suitable for standard CMOS technology with low-power low-cost VLSI implementation. It is well applied when embedded into system-on-chip (SoC) circuit designs.