A Temperature and Supply Voltage Independent CMOS Voltage Reference Circuit

A pure CMOS threshold-voltage reference (V TR ) circuit achieves temperature (T) coefficient of 5 μV/°C (T = -60 ∼ +100°C) and supply voltage (V DD ) sensitivity of 0.1 mV/V (V DD = 3 ∼ 5V). 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.