Title :
A 1.8-V 1.6-GSample/s 8-b self-calibrating folding ADC with 7.26 ENOB at Nyquist frequency
Author :
Taft, Robert C. ; Menkus, Chris A. ; Tursi, Maria Rosaria ; Hidri, Ols ; Pons, Valerie
Author_Institution :
Nat. Semicond., Munich, Germany
Abstract :
This study demonstrates for the first time the significant performance enhancement that calibration brings to folding-interpolating analog-to-digital converters (ADCs). The resulting 1.8-V ADC in 0.18-μm CMOS achieves a conversion rate exceeding 1.6 GSample/s, since the amplifier device sizes can be minimized to maximize speed without the restriction of device matching. At 1.6 GS/s, the ADC achieves 0.15 LSB DNL, 0.35 LSB INL, 7.6 effective number of bits (ENOBs) at 100 MHz input, and 7.26 ENOB at Nyquist. At this speed, current consumption from a single 1.8-V supply is 245 mA analog, 185 mA digital, and 90 mA for the LVDS drivers. The ac performance is approximately 1.5 ENOBs higher compared to the same circuit with calibration disabled. The use of best design practices to optimize the ADC linearity prior to introducing calibration resulted in this small required dynamic calibration range, simplifying the calibrator circuitry and resulting in stable continuous performance over time without recalibration. Therefore, the fully on-chip calibration is performed automatically, just one time at power-up.
Keywords :
CMOS analogue integrated circuits; amplifiers; analogue-digital conversion; calibration; high-speed integrated circuits; integrated circuit design; 0.18 micron; 1.8 V; 100 MHz; 185 mA; 245 mA; 90 mA; CMOS analog integrated circuits; LVDS drivers; Nyquist converter; Nyquist frequency; amplifier device; analog-to-digital converters; folding-interpolating ADC; high-speed techniques; interpolation; self-calibration; Analog-digital conversion; CMOS technology; Calibration; Design optimization; Driver circuits; Energy consumption; Frequency conversion; Linearity; Pipelines; Preamplifiers; 65; Analog-to-digital conversion; CMOS analog integrated circuits; Nyquist converter; calibration; folding; high-speed techniques; interpolation;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2004.836242