A sub-1-ppm/°C curvature-compensated bandgap voltage reference

Abstract

A new sub-1-ppm/°C curvature-compensated bandgap voltage reference (BGR) is presented in this paper. The Complementary to Absolute Temperature (CTAT) voltage component of a forward biased BJT is first well balanced with a Proportional to Absolute Temperature (PTAT) voltage, leaving only a high order logarithmic error with the form of TlnT. This residual non-linear error is corrected by a difference of two CTAT voltages with different non-linear terms through controlling the collector currents of BJTs, which can achieve an ideal non-linear compensation. All the circuits are designed in a standard 0.35-pm CMOS process. The post-simulation results show the proposed BGR achieves temperature coefficient (TC) of 0.7 ppm/°C over temperature range of −40 °C to 125 °C and power supply rejection (PSR) of −104 dB at 3.6 V power supply. The line regulation of the output reference voltage is 0.1 mV/V in the supply range of 24.5 V. The maximum dissipating current from the supply is 25.45 μA.