A Hybrid BJT/Subthreshold MOSFET-Based Voltage Reference with a sub 1ppm/℃ Temperature Coefficient

This paper presents a voltage reference design that combines a BJT-based voltage reference with a weak inversion current correction technique to reduce the TlnT nonlinearity inherent in most BJT-based reference. The proposed design combines the temperature characteristics of both BJTs and subthreshold MOSFETs to eliminate both the T and the TlnT effects in the output of the voltage reference. Simulation results show that the proposed voltage reference will exhibit a sub 1ppm/℃ temperature coefficient over the temperature range from -40℃ to 125℃. The power supply ripple rejection is -70dB while operating between 1.5V and 2V in a standard 180nm bulk CMOS process. The design delivers low line-regulation of 0.028%.