一种带有数字修调的高精度带隙基准电路

A High Precision Bandgap Reference Circuit with Digital Trimming

采用一种具有较高固有精度的带隙核心结构,设计了一种应用于开关电源芯片的带数字修调的高精度带隙基准电路。通过对传统Brokaw基准结构进行改进,提出了一种新型的带隙基准核心电路,使得由于失配导致的基准电压变化从6.4mV减小到3.4μV,提高了带隙基准的固有精度。基于CSMC 0.5μm BCD工艺对电路进行仿真,结果表明,在-40℃~120℃的温度范围内,基准的温度系数为5.2×10^(-6)/℃,电源抑制比分别为-167.5dB@dc,-89.6dB@1 MHz。

Based on a reference structure with increased intrinsic accuracy, a high precision bandgap voltage reference with digital trimming was proposed for the application of switching power supply chip. By improving the traditional Brokaw bandgap reference structure, a new bandgap reference core circuit was proposed. The error caused by mismatch was decreased from 6.4 mV to 3.4 /μV, thus the intrinsic accuracy was increased. The circuit was implemented in CSMC 0.5 μm BCD process. The simulation results showed that the temperature coefficient was 5.2 ×10 6/℃ in the temperature range of --40 ℃ -120 ℃. Additionally, the PSRR of the proposed bandgap reference was --167.5 dB@dc and --89.6 dB@IMHz.