一种自适应恒定平均电压输出电路设计  

An adaptive constant average voltage output circuit

作　　者：李琴鹏 孙江[1] 左世柱 李征洋 罗章成 LI Qinpeng;SUN Jiang;ZUO Shizhu;LI Zhengyang;LUO Zhangcheng(School of Information Science and Technology,Southwest Jiaotong University,Chengdu611756,China)

机构地区：[1]西南交通大学信息科学与技术学院,四川成都611756

出　　处：《电子元件与材料》2024年第6期701-707,共7页Electronic Components And Materials

基　　金：国家自然科学基金(62174139)。

摘　　要：在电子点火器应用中,为解决传统方案中LDO效率低、DC-DC需要外挂电容、电感的问题,提出了一种自适应恒定平均电压输出电路。电路输出为PWM波,当电源电压变化时,通过自动调整PWM波的占空比实现了恒定的平均电压输出。通过改变外接采样电阻的比值可以调整输出的平均电压大小。电路为开环控制,不需要考虑闭环稳定性问题,其控制简单可行,具有与DC-DC相比拟的高效率,但无外围电感、电容,便于集成和小型化应用。电路采用0.18μm BCD工艺设计,仿真和测试结果表明,在电源电压3.2~4.2 V下,实现了输出平均电压恒定,误差小于±1%;通过改变采样电阻比值,实现了输出平均电压在1.5~3.6 V之间连续可调。In order to solve the problem of low efficiency of LDO and peripheral capacitors or inductors of DC-DC in the electronic igniter applications,an adaptive constant average voltage output circuit was proposed.The circuit output produced a PWM wave and a constant average voltage output was achieved by automatically adjusting the duty cycle of the PWM wave in response to variations in the power supply voltage.The average output voltage can be adjusted by changing the proportion of the external sampling resistors.The circuit is operated in open-loop with simple and feasible feature,and no close-loop stability consideration is needed.Meanwhile,it achieves high efficiency that comparable with DC-DC,but without peripheral inductors and capacitors,so the integration and miniaturized applications was facilitated.The circuit was designed with 0.18μm BCD process.The simulation and test results show that under the power supply voltage of 3.2-4.2 V,a constant average output voltage can be achieved with an error of less than±1%;By changing the sampling resistance ratio,the average output voltage can be continuously adjusted within 1.5-3.6 V.

关 键 词：恒定平均电压 自适应占空比 PWM 开环控制 无片外电感电容 

分 类 号：TN787[电子电信—电路与系统]