SPRUI33H November 2015 – June 2024 TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1
The internal DC-DC regulator is disabled by default. To use this supply, the TMS320F28004x MCU core must power up initially with the internal LDO (VREG) and then transition to the internal DC-DC regulator by way of the application software. Note that VREGENZ low is required for both the internal LDO and the internal DC-DC to function. Perform the following procedure to enable the internal DC-DC regulator:
The application can switch back to the internal LDO at any time. This can be accomplished by clearing the DCDCCTL.DCDCEN bit and waiting 80μs for the internal LDO to power up.