Title :
250-mV Supply Subthreshold CMOS Voltage Reference Using a Low-Voltage Comparator and a Charge-Pump Circuit
Author_Institution :
Chungbuk Nat. Univ., Cheongju, South Korea
Abstract :
This brief proposes a subthreshold CMOS voltage reference circuit, which reduces the minimum supply voltage by replacing the analog amplifier in the conventional CMOS voltage reference circuit with a low-voltage comparator, a charge-pump circuit, and a digital control circuit. The subthreshold CMOS voltage reference circuit was fabricated using a 0.11-μm CMOS process. Its core area was 0.013 mm2 and it consumed 5.35 μW at VDD = 250 mV and fCLK = 1 MHz. Its minimum supply voltage was 242 mV. Ten sample chips generated 193-207-mV reference voltage with 0.4-3.2-mV/100-mV line sensitivity at VDD = 250-400 mV and 58-186 ppm/°C temperature coefficient at 10 °C-90 °C.
Keywords :
CMOS integrated circuits; amplifiers; charge pump circuits; comparators (circuits); low-power electronics; reference circuits; analog amplifier; charge-pump circuit; digital control circuit; frequency 1 MHz; low-voltage comparator; power 5.35 muW; size 0.11 mum; subthreshold CMOS voltage reference; temperature 10 degC to 90 degC; voltage 250 mV to 400 mV; CMOS integrated circuits; Capacitors; Charge pumps; MOSFET; Threshold voltage; Voltage control; CMOS; Charge pump; comparator; low voltage; subthreshold; voltage reference;
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2014.2350354