Title :
Comparator with built-in reference voltage generation and split-ROM encoder for a high-speed flash ADC
Author :
Yong Chen ; Pui-In Mak ; Jiale Yang ; Ruifeng Yue ; Yan Wang
Author_Institution :
Inst. of Microelectron., Tsinghua Univ., Beijing, China
Abstract :
Two circuit techniques for performance enhancement of high-speed flash ADCs are proposed. A calibration-intensive dynamic comparator features an improved built-in reference voltage generation scheme to alleviate the issue of kickback noise, and a proper reset function to clean the memory effect due to the dielectric relaxation in the capacitors, yielding better static and dynamic linearity performances. The second is a split-ROM encoder, which halves the signaling path to lower the parasitics, while boosting the back-end processing speed with small power. The feasibility of them is demonstrated via a 5-bit flash ADC designed in 65nm CMOS. With 3.69mW of power, the ADC operated at 2GS/s exhibits an ENOB of >4.5 bits up to an ERBW of 3.6GHz. The DNL and INL are within +0.091/-0.071 and +0.066/-0.062 LSB, respectively.
Keywords :
CMOS memory circuits; analogue-digital conversion; calibration; comparators (circuits); dielectric relaxation; integrated circuit noise; read-only storage; reference circuits; CMOS; DNL; ENOB; ERBW; INL; LSB; analog-digital converter; back-end processing speed; built-in reference voltage generation scheme; calibration-intensive dynamic comparator; capacitor; complementary metal oxide semiconductor; dielectric relaxation; differential nonlinearity; dynamic linearity; effective number of bit; effective resolution bandwidth; frequency 3.6 GHz; high-speed flash ADC; integral nonlinearity; kickback noise; least significant bit; memory effect; power 3.69 mW; read-only memory; reset function; signaling path; size 65 nm; split-ROM encoder; word length 5 bit; Calibration; Capacitors; Clocks; Latches; Read only memory; Switches; Transistors;
Conference_Titel :
Signals, Circuits and Systems (ISSCS), 2015 International Symposium on
Conference_Location :
Iasi
Print_ISBN :
978-1-4673-7487-3
DOI :
10.1109/ISSCS.2015.7203923