Abstract
KEYWORDS – EV and EHV, Li-Ion Battery Monitoring IC, High Voltage SOI Process, High Accuracy, High Reliability
ABSTRACT –
A battery system of HEVs(Hybrid Electric Vehicles) is equipped with a Li-ion battery and a battery monitoring ECU that prevents the over-charge/discharge and short circuit. The voltage of a Li-ion battery is adopted from 100 to 400V. And a Li-ion battery system is requested to make maximum use of the battery capacity for fuel efficiency. When the battery voltage is 300V, the conventional battery monitoring ECU uses 8 pieces of ICs, which can monitor the voltage of the 7 Li-ion cells at a maximum. In this study, we developed the novel high-breakdown-voltage and high-accurate SOI process for Li-ion-battery-monitoring ICs, which can monitor the voltage of the 24 Li-ion cells at a maximum. As a result, the new battery monitoring ECU uses 3 pieces of ICs and the novel battery monitoring ECU can be reduced its size by 30% compared to the conventional ECU.