A 10-bit 20-Msample/s 49mW CMOS pipelined A/D converter

A 10-bit 20-Msample/s CMOS pipelined analog-to-digital converter (ADC) is proposed, which is implemented in a 0.6μm double-poly double-metal CMOS process. The digital correction technique is used to relax the offset requirement of the comparators. To reduce signal-dependent charge injection and substrate noise injection, the bottom-plate sampling technology is applied. A sample-and-hold amplifier (SHA) is also used to improve the signal-to-noise and distortion ratio (SNDR) performance and the linearity of ADC. The circuit is simulated by the Hspice software which is based on CSMCs library of 0.6μm mixed-signal CMOS model. The simulation results reveal that the ADC designed with this method achieves the SNDR of 58dB at full speed of 20MHz when input frequency is 5MHz. Furthermore, the ADC consumes 49mW power at 5V supply voltage with a low power operational transconductance amplifier (OTA) and the dynamic comparators.