Battery-electric vehicles typically carry both a high-voltage traction battery and a low-voltage battery. The DC-DC converter steps the high voltage of the traction battery pack down to a constant 12V or 24V, powering all of the vehicle's electrical loads while also charging the auxiliary battery. Our automotive DC-DC solution, built on an automotive-grade MCU, uses a phase-shifted full-bridge topology and supports node control over CAN.
Key Points
- MCU with functional safety rating
- Multi-channel high-precision ADC inputs for real-time voltage and current sensing
- Phase-shifted full-bridge control working seamlessly with synchronous rectification for greatly improved conversion efficiency
- DC-DC node control over the CAN bus
- Generic software library portable across different MCUs
Solution Overview
An automotive DC-DC with phase-shifted full-bridge topology based on an automotive-grade MCU. It uses a high-voltage/low-voltage isolated control scheme, with high-speed ADCs sampling input and output voltages and currents in real time to perform the high-to-low voltage conversion, while synchronous rectification further improves efficiency.
Recommended Devices
- FS32K144UAT0VLHT
Core Components
- Main MCU: NXP, GD, etc.; full part number available on request
- Phase-shifted full-bridge MOSFETs: ON; full part number available on request
- Synchronous rectification MOSFETs: Nexperia; full part number available on request
- MOSFET drivers: ON; full part number available on request
- Current sensing IC: ON; full part number available on request
- LDO: ON; full part number available on request
- CAN transceiver: NXP; full part number available on request
Applications
Primary applications, extended applications, automotive DC-DC, digital power related applications
Reference Design DCDC-EVB
- All components selected to automotive grade
- Safety-isolated circuit design
- Phase-shift control algorithm
- Voltage-mode control algorithm
- Peak current control algorithm
- Synchronous rectification algorithm
- Complete hardware design reference materials
- Complete software design reference materials
Functional Block Diagram
