A 12-bit 10-MS/s Pipelined SAR ADC Sharing Flash ADC and Residue Amplifier of Multiplying DAC

Abstract

A pipelined successive approximation register (SAR) analog -to -digital converter (ADC) is proposed for display applications. It consists of three stages and a digital error correction logic (DCL). To reduce the power consumption and area of the proposed pipelined SAR ADC, the flash ADC (FADC) and the residue amplifier of the stages 1 and 2 are shared, and the stage 3 has an architecture of 7 -bit asynchronous SAR ADC using a capacitor digital -toanalog converter (CDAC). The conversion pause function of the 7 -bit asynchronous SAR ADC improves the performance of the pipelined SAR ADC by stabilizing the reference voltages through nonoverlapping operation between the FADC and SAR ADC. The proposed pipelined SAR ADC is designed using a 180-nm CMOS process with a supply of 1.8V. The designed pipelined SAR ADC has a SNDR of 72.97 dB and an ENOB of 11.83 bits for an analog input signal with a frequency of 4.7 MHz at a sampling rate of 10 MHz. Its area and power consumption are 0.282 mm 2 and 7.9 mW, respectively.