A 2.3-ppm/℃ High-Order Compensated Bandgap Reference With Low-Cost Current Trimming

This paper presents a high-precision bandgap voltage reference (BGR) using a low-cost current trimming network. The high-order curvature compensation is implemented by injecting a current with concave temperature curve characteristics into the bandgap core circuit. Meanwhile, a current-based trimming circuit is proposed to obtain a precise reference voltage while reducing the circuitry complexity and area consumption. Compared with traditional resistor-based trimming networks, the proposed trimming scheme does not require large-area resistors and complex digital logic circuits. Compared with prior current-based trimming scheme, the proposed one does not require extra current mirrors. The proposed BGR was designed in a 180nm BCD process and post-layout simulation results show that the temperature coefficient (TC) is lower than 2.3 ppm/°C within a wide temperature range of -40℃ to 125℃. Additionally, the power supply rejection ratio (PSRR) of -69dB at 100Hz is achieved. The active area of the proposed BGR is 383 µm × 259 µm, where the area of the proposed trimming circuit only occupies 16%.