基于数字电位器的可编程电压基准源设计

The Design of Programmable Voltage Reference Based on Digital Potentiometer

在电子设计中为了灵活准确地设置电压基准值,设计了可编程电压基准源电路。详细阐述了电路的设计思路和工作原理。利用5片2.048 V带隙电压基准源芯片串联产生10.24 V电压作为基准。随后创新地利用单片机控制1024抽头的数字电位器对基准电压进行分压,结合精准运放的反向放大电路,最后输出-10.24 V到10.22 V的可编程精准电压值,输出电压分辨力达20 m V。测试结果表明,该电路具有输出线性度好、精度高、性能稳定等优点。

In order to set the value of voltage reference smartly and accurately in electronic design,a voltage refer-ence circuit of which output voltage can be programmed precisely is designed. The design idea and the working prin-ciple of the circuit are described in detail.Five 2.048 V bandgap type reference chips are connected in series,andoutput 10.24 V voltage as reference of other part of the circuit.And then a 1024-position digital potentiometer con-trolled by MCU is used to divide the 10.24 V reference voltage. Attributes to reverse amplifier circuit which useshigh precision amplifier,the whole circuit can finally outputt accurate and programmable voltage from-10.24 V to10.22 V. The output resolution can reach 20 m V. Test result shows that the circuit has the advantage of good linearoutput characteristics,high precision and reliable performance.