关键词: 隔离设计, NSI1311-Q1, 差分运放, 数据采集, 抗干扰

Abstract: Aiming at the isolated sampling of switching power supply bus voltage and current by supply and distribution test equipment, a design scheme of isolated bus voltage and current acquisition circuit is proposed. Based on the hardware circuit, the working principle of the isolation amplifier NSI1311-Q1 is analyzed, and the amplification of data and single-end analog output are realized by adding differential operational amplifier circuits, providing a reasonable isolation-type acquisition circuit and a derivation of relevant formulas. Experimental results show that the sampling accuracy of the isolated acquisition circuit meets the demand of power supply and distribution test equipment for isolated data acquisition, and it has strong anti-interference with strong engineering practical value.

Key words: isolation design, NSI1311-Q1, differential operational amplifier, data acquisition, anti-interference