一种高电源抑制比快速启动的带隙基准的设计

文章采用 5 V、0.35 $ \mu $m CMOS 工艺, 设计一种适用于低噪声高速系统的带隙基准电压源电路。为了保证电路具有较高的电源抑制比(power supply rejection ratio, PSRR), 设计一种抑制电源电压波动的负反馈回路, 并且在电路中采用具有较高增益的两级放大器结构。针对某些系统快速启动的需求, 设计快速启动电路, 当电源上电时启动电路直接作用于基准电压, 加速带隙基准电路的启动, 在电路正常启动后通过开关管使启动电路停止工作。仿真结果表明, 温度在 $ -40 \sim 125 $ ℃ 范围内, 带隙基准的温漂系数为 $ 13.05 \times 10^{-6} \, ^{\circ}C^{-1} $; 低频时 PSRR 为 100.6 dB; 线性调整率(line regulation, LNR)为 0.024 mV/V; 启动时间为 4 $ \mu $s。

Based on 5 V 0.35 $ \mu $m CMOS process, this paper proposes a bandgap voltage reference circuit suitable for low-noise and high-speed systems. In order to ensure that the circuit has a higher power supply rejection ratio (PSRR), a negative feedback loop is designed to suppress the fluctuation of the power supply, and a two-stage amplifier structure with higher gain is used in the circuit. A fast start-up circuit is designed to meet the requirements of some high-speed systems for the start-up sequence. When the power supply starts to be turned on, the fast start-up circuit directly acts on the reference voltage, which accelerates the start-up of the bandgap reference. After the bandgap voltage reference is normally started, the start-up circuit stops working by turning off the transistors quickly. According to the simulation results, the proposed bandgap voltage reference has a temperature drift coefficient of $ 13.05 \times 10^{-6} $ $ ^{\circ} $C $ ^{-1} $ between -40 $ ^{\circ} $C and 125 $ ^{\circ} $C and the PSRR at low frequency is 100.6 dB. In addition, its line regulation (LNR) and starting time are 0.024 mV/V and 4 $ \mu $s, respectively.