2-Phase Synchronous Buck Converter with Advanced Voltage Mode Control and Current Balancing
Description: This code example demonstrates a closed loop voltage mode control implementation for dsPIC33CK. It has specifically been developed for the EPC9143 Rev4.0 1/16 brick converter.
The board starts up the buck converter automatically when power is applied to the board, providing a regulated output voltage of 12 V at the output of the converter. The startup procedure is controlled and executed by the power controller state machine (PWRLIB_BUCK) and includes an configurable startup procedure with power-on delay, ramp up period and power good delay before dropping into constant regulation mode. An additional fault handler (FUNLIB_FAULT_HANDLER) shuts down the power supply if the input voltage is outside the defined range of 18V to 72.5V (UVLO/OVLO) or if the output voltage is more than 0.5V out of regulation for more than 10 milliseconds.
The control loop is based on a digital type IV compensator (4P4Z controller).
Operation Parameters:
- Input Voltage: 18 V to 61 V
- Output Voltage: 12.0 V
- Switching Frequency: 500 kHz
- Control Frequency: 500 kHz
- Cross-Over Frequency: ~20 kHz (depends on VIN and if AGC is on/off)
- Phase Margin: ~ 50°
Required Hardware:
- EPC9143: EPC9143 16th Brick Non-Isolated Step Down Converter, Revision 4.0
- EPC9531: EPC9531 test fixture for EPC9143 16th brick reference design
Device Support:
Libraries:
- PWRLIB_BUCK - Single Phase Buck Converter State Machine & Peripheral Configuration Template
- FUNLIB_FAULT_HANDLER - Generic Fault Handler Template
Software Tools:
- DCLD - Digital Control Library Designer, version v0.9.7.99 or higher
- Download Digital Control Library SDK for Windows here (Using previous versions will result in naming conflicts of labels and function names)
Development Tools:
- MPLAB X v5.35
- MPLAB X XC16 C-Compiler, v1.50
History:
- | 03/24/2020 | 1.0 | M91406 | Initial Release
- | 05/21/2020 | 1.1 | M91406 | Dual Phase Loop with 4P4Z Control
- | 05/26/2020 | 1.2 | M91406 | Dual Phase Loop with 4P4Z Control - Update
- | 06/18/2020 | 1.3 | M91406 | Dual Phase Loop with 4P4Z Control with AGC