TMS320F280049C: Internal DC/DC Converter

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
via application software. Follow the procedure below to enable the internal DC-DC regulator:
1. Set EALLOW bit.
2. Set the DCDCCTL.DCDCEN bit.
3. Wait for DCDCSTS.SWSEQDON to equal 0x1.
• If this bit does not get set then the transition from VREG to DC-DC was not successful (check the
hardware connections on the application board). Consult the F28004x Data Manual for schematic
details.
4. Wait for DCDCSTS.INDDETECT to equal 0x1.
• If this bit does not get set then the inductor was not detected on the VSW pin.
• Note that steps 3 and 4 can be combined.
5. Delay 80us for the DC-DC regulator output to settle (delay function based on 10MHz CPU clock).
Device Identification and Configuration Registers www.ti.com
84 SPRUI33B–November 2015–Revised January 2019
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TMS320F28004x System Control
6. EDIS
The procedure to enable the internal DC-DC regulator must be completed prior to all other initialization
functions and application code.