A Temperature and Supply Voltage Independent CMOS Voltage Reference Circuit

摘要

A pure CMOS threshold-voltage reference (V_(TR)) circuit achieves temperature (T) coefficient of 5 μV/℃ (T = -60 ～ +100℃) and supply voltage (V_(DD)) sensitivity of 0.1 mV/V (V_(DD) = 3 ～ 5 V). A combination of subthreshold current, linear current and saturation current in n-MOSFETs provides a small voltage and temperature dependence. Three different regions in Ⅰ-Ⅴ characteristics of MOSFETs generate a constant V_(TR) based on threshold voltage at 0 K. A feedback scheme from the reference output to gates of n-MOSFETs extremely stabilizes the output. The circuit consists of only 17 MOSFETs and its simple scheme saves the die area, which is 0.18 mm~2 in the TEG (Test Element Group) chip fabricated by 1.2 μm n-well CMOS process.