Reference design for an automotive 400-V battery to 12 V, 3.6-kW DC/DC converter.
Most new Electric Vehicles (EVs) have high-voltage battery packs, but the auxiliary system such as lightning system, infotainment system, safety systems, etc. in cars and other vehicles still runs at 12V DC. Although the power consumption of these individual systems doesn’t seems high, the cumulative power of all the system when running together can add to 1000s of watts. Therefore, it is essential to have a safe and reliable DC/DC converter that can work in harsh working conditions and supply constant 12V DC output.
To tackle this problem, Texas Instruments have designed a 3.6 kW DC/DC converter that can work with wide input from 200V to 470V and give a 12 V output. The output is adjustable from 9V to 15V with a maximum current of 300Amps. The output is scalable to 800-V input systems, with tight regulation of < ±1%. The converter also provides soft-switching using a phase-shifted full bridge analog control loop. A circuit breaker is applied for overcurrent and overvoltage protection. The reference design employs Sic MOSFETs on the high-voltage side and is driven by 5.7-kVRMS, reinforced isolated dual-channel gate drivers.
The reference design also features Zero Voltage Switching (ZVS) over a wide range of operating conditions. It also features various light load management features such as dynamic SR on and off control and burst modes, etc. The design also has a host MCU for supervision and current and voltage loop control. A fast circuit breaker is implemented to comply with safety in automotive.
This reference design has been tested by Texas Instruments. To simplify the design, TI has provided the firmware libraries, BOM, Gerber files, etc, which can be found on the Design guide PDF of TIDA-020031. You can find additional data about the reference design on the company’s website. To read more about this reference design click here.