2 Gate Drivers in xEV On-Board Chargers/DC-DC Converters

The three main components that factor into the performance of an onboard-charger / DC-DC converter system are the OBC power factor correction (PFC) stage, the OBC DC-DC stage, and the high-voltage to low-voltage (HV-LV) DC-DC stage. Each of these subsystems have switches that gate drivers help drive. The switch is what is doing the actual switching, handling the majority of the power transfer and can be a MOSFET, IGBT, SiCFET or GaN. Finally, the gate driver is the in between of the controller and switch, the drive strength of the gate driver can determine how fast the switch turns on or off making the system more efficient. The power level of an OBC/DC-DC system generally requires drive strength of >4A such as in the UCC27624-Q1 or UCC27301A-Q1. Features such as UVLO and overcurrent protection help protect the switch from accidental damage and make the system more reliable. Choosing the best gate driver for the system helps get the most out of each other component making sure high performance stays affordable.

TI’s gate drivers come in non-isolated and isolated varieties. Isolated drivers provide a barrier for use across high voltage differentials, protecting both components and people. Non-isolated gate drivers are used when there is no such differential or along with external isolators in order to optimize the system. Depending on the switch’s placement in the system- connected to ground or referencing a floating voltage – different types of TI Gate Drivers best service these FETs.

Low-side drivers are utilized when the power switch is referenced to ground. TI offers single or dual channel low-side drivers, referring to whether the gate driver can operate one or two ground referenced switches. Half-Bridge drivers operate one switch referenced to ground, and another referenced to the “switch node” that has a floating voltage. Choosing the right gate driver is determined by the type and characteristics of the xEV OBC/DC-DC system.