Title :
A 10-bit 50-MS/s SAR ADC for dual-voltage domain portable systems
Author :
Wei-Hao Tsai ; Che-Hsun Kuo ; Soon-Jyh Chang ; Li-Tse Lo ; Ying-Cheng Wu ; Chun-Jen Chen
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
Abstract :
The analog-to-digital converter (ADC) is an essential component providing the interface between the sensed analog signal and the corresponding digital representation for a portable ultrasonic systems. In order to extend the battery life for the portable system, a low-voltage ADC is crucial for saving the power. However, the sensed analog signal is usually larger than the tolerable range of a low-voltage ADC. A level shifter, which possibly consumes more power than ADC, is therefore adopted to solve this problem. This paper presents a 10-bit 50-MS/s successive approximation register (SAR) ADC by manipulating simple but effective circuit design techniques to operate at dual-voltage domain without the need of an additional level shifter for shrinking the input signals. Particularly, we propose a technique to implement the ADC with 3.3-V I/O devices and 1.2V MOS transistors. The proof-of-concept design was fabricated in TSMC 130-nm 1P8M CMOS technology. It consumes 1.6 mW at a 50 MS/s sampling frequency and about 2 MHz sinusoidal input signal with 1.65V input common-mode voltage and 2Vp-p differential input amplitude. The measurement result shows an ENOB of 9.15 bits, and both the DNL and INL are within 1 LSB. The active area is 0.226 mm2.
Keywords :
CMOS logic circuits; MOSFET; analogue-digital conversion; flip-flops; portable instruments; ultrasonic devices; CMOS technology; DNL; INL; MOS transistors; SAR; SAR ADC; TSMC; analog-to-digital converter; circuit design techniques; digital representation; dual-voltage domain portable systems; low-voltage ADC; portable ultrasonic systems; sensed analog signal; successive approximation register; Arrays; Capacitors; Frequency measurement; Latches; Metals; Power demand; Switches; Analog-to-digital converter (ADC); dual-voltage domain; portable; successive approximation register (SAR);
Conference_Titel :
Circuits and Systems (ISCAS), 2015 IEEE International Symposium on
Conference_Location :
Lisbon
DOI :
10.1109/ISCAS.2015.7169174