低温漂高PSRR新型带隙基准电压源的研制

利用带隙电压基准的基本原理,结合自偏置共源共栅电流镜以及适当的启动电路,设计了一种新型基准电压源。获得了一个低温度系数、高电源抑制比的电压基准。通过对输出端添加运算放大器,把带隙基准电路产生的1.2 V电压提高到3.5 V,提高了芯片性能。用Cadence软件和CSMC的0.5μm CMOS工艺进行了仿真,结果表明,当温度在-20～+120℃,温度系数为9.3×10-6/℃,直流时的电源抑制比为-82 dB。该基准电压源能够满足开关电源管理芯片的使用要求,并取得了较好的效果。

Research and Development Design of Bandgap Voltage Reference with Low Temperature-Drift and High PSRR

A new voltage reference applicable for switching power supply is designed and simulated.The voltage reference with low temperature-drift and high PSRR was acquired using traditional principle of bandgap reference together with the self-biased casecode current mirror structure and setup circuit.The reference voltage was improved from the traditional value of 1.2 V to 3.5 V by applying an operational amplifier at output terminal.The circuit was simulated with Cadence tool and 0.5 μm CMOS model.The results show that the temperature coefficient is 9.3 × 10-6/℃ over the temperature range of-20～+120℃ and PSRR is -82 dB at DC.The measured results indicate that the designed voltage reference is prospective for application in switching power management circuit.