Trimmable bandgap reference circuit with exponential curvature compensation

Abstract

This paper proposes an improved exponential curvature-compensated bandgap reference circuit to exploit the exponential relationship between the current gain β of the bipolar junction transistor (BJT) and the temperature as well as reduce the influence of resistance-temperature dependency. Considering the degraded circuit performance caused by the process deviation, the trimmable module of the temperature coefficient (TC) is introduced to improve the circuit stability. The circuit has the advantages of simple structure, high linear stability, high TC accuracy, and trimmable TC. It consumes an area of 0.09 ​mm² when fabricated by using the 0.25-μm complementary metal-oxide-semiconductor (CMOS) process. The proposed circuit achieves the simulated power supply rejection (PSR) of about −78.7 ​dB@1 ​kHz, the measured TC of ∼4.7 ​ppm/°C over a wide temperature range from −55 ​°C to 125 ​°C with the 2.5-V single-supply voltage, and the tested line regulation of 0.10 ​mV/V. Such a high-performance bandgap reference circuit can be widely applied in high-precision and high-reliability electronic systems.