Design of High Precision CMOS Bandgap Reference
Lizhe Yu · Semiconductor Technology · 2007
The second-order nonlinear effect of the transistor VBE current varying with temperature in the conventional CMOS bandgap reference was analyzed.A curvature compensation method for the proportion to absolute temperature(PTAT) was proposed and a high precision CMOS bandgap reference based on this method was designed.The bandgap referebce was implemented in SMIC 0.18 μm CMOS technology,which had a good temperature coefficient(TC)and a low power supply rejection ration(PSRR).Cadence Spectre simulation result shows that the circuit has an accuracy of 7.7×10-6/℃ at-40 to 140 ℃ and a power supply rejection ration of-76 dB at low frequency.The circuit can operate at the range from 2 to 4.5 V.