具有欠压锁定功能的PWM控制器带隙基准电路的实现

Realization of bandgap voltage reference circuit with UVLO for PWM controller

目的设计一款应用于PWM控制器的带隙基准。方法前级的欠压锁定电路在电源电压上升到8.2V时才能开启,当电源电压下降到7.8V后级电路关断,既保证了整个电路的正常工作,又节省了电路的功耗。结果 CADENCE Spectre软件仿真结果表明:温度为25℃时,带隙基准输出电压为5.006 5V;在-55℃～125℃的温度变化范围内,基准的温度稳定性为0.17mV/℃;电源电压12V≤Vcc≤25V,基准输出的最大变化为0.233mV;基准输出电流1mA≤Io≤20mA,输出电压的最大变化为1.81mV;基准电路的输出短路电流为-105mA。结论版图基于华越微电子有限公司SB45V双极工艺流程和版图层次设计,流片测试结果证明本单元的设计满足要求。

Aim The bandgap voltage reference is designed based on PWM controller.Methods The under-voltage lockout circuit that is located at the front stage turns on when the supply voltage is up to 8.2V,and turns off when the supply is down to 7.8V,which makes the whole PWM controller system work stably and save the power dissipation.Results The circuit is simulated by CADENCE Spectre,and the results show that the output of the reference voltage circuit is 5.0065V at 25℃,the temperature stability is 0.17m V/℃,output short current is-105mA,the line regulation is 20mV,load regulation is 1.81mV.Conclusion The layout is done based on the process flow and layout levels of bipolar 45V process provided by HUAYUE Microelectronics Company,and the test results proved that the current amplifier presented in this paper meets the design requirements.