A PACK VOLT SENSING CIRCUIT USING ISOLATION AMPLIFIER FOR A HYBRID ELECTRIC VEHICLE AND THE SENSING METHOD THEREOF

摘要

A circuit and a method of sensing a battery pack voltage for a hybrid electric vehicle using an isolation amplifier are provided to remarkably improve reliability for a measured voltage by removing high-frequency noise of a primary-side pack voltage signal to transmit the noise to a secondary side and by removing high-frequency noise of a secondary-side pack voltage signal to transmit the noise to a BMS(Battery Management System) board. A circuit(20) of sensing a battery pack voltage for a hybrid electric vehicle using an isolation amplifier includes a primary-side secondary active filter(21), an isolation amplifier(22), a differential amplifier(23), and a secondary-side active filter(24). The primary-side secondary active filter removes high-frequency noise to transmit the noise to the isolation amplifier when a pack voltage divided by a resistor in a battery pack(10). The isolation amplifier amplifies the pack voltage applied to the primary-side secondary active filter to transmit the pack voltage to the secondary-side differential amplifier. The differential amplifier recoveries a secondary-side pack voltage signal to transmit the pack voltage signal to the secondary-side secondary active filter. The secondary-side secondary active filter removes high-frequency noise of the pack voltage signal applied from the differential amplifier to transmit the noise to the BMS board(30).