A low temperature coefficient voltage reference utilizing BiCMOS compensation technique
This paper presents a low temperature coefficient BiCMOS voltage reference circuit designed in IBM's 8HP Silicon-Germanium (SiGe) technology platform. A BiCMOS compensation approach by combining the temperature properties of HBTs and CMOS transistors has been employed: the Complementary to Absolute Temperature (CTAT) current is generated by a SiGe HBT, while the Proportional to Absolute Temperature (PTAT) current is generated by MOSFETs operating in the subthreshold region. In addition, by adding a nonlinear component, a higher level of temperature compensation is achieved. Simulation results show that with a power supply of 1.2 V, the circuit generates an output voltage of 0.981 V with a temperature coefficient of 0.6 ppm/°C over the temperature range of -25°C to 125°C.