EV, PHEV and HEV vehicles are equipped with two types of batteries: a high-voltage battery for drive and a 12V auxiliary battery. The DC/DC converter converts 200 to 800V from the high-voltage battery to 12V low voltage. This lower voltage powers the head lamps, windshield wipers, instrument cluster, ECUs and charges the auxiliary 12V battery.
The DC/DC converter uses low on-resistance Si IGBTs or SiC MOSFETs to reduce conversion loss. The on-resistance has the characteristic to drop as the gate voltage rises so it is recommended to design a gate drive circuit using, for example, an Si IGBT with a high voltage of around 15V or an SiC MOSFET with a high voltage of around 18V.
ABLIC has a lineup of LDOs that can output the high voltage required by the gate driver circuit. In addition, our lineup offers LDOs with built-in watchdog timers for monitoring MCUs, battery monitoring ICs used for fast monitoring of abnormal voltages in 12V auxiliary batteries and operational amplifiers ideal for charge current monitoring. With its wide range of products, ABLIC can provide ICs ideal for DC/DC converters.