LM3S6611 Datasheet, PDF (170/647 Pages) List of Unclassifed Manufacturers – Microcontroller

System Control
5.2.3
Power Control
The Stellaris^® microcontroller provides an integrated LDO regulator that is used to provide power
to the majority of the controller's internal logic. For power reduction, the LDO regulator provides
software a mechanism to adjust the regulated value, in small increments (VSTEP), over the range
of 2.25 V to 2.75 V (inclusive)—or 2.5 V ± 10%. The adjustment is made by changing the value of
the VADJ field in the LDO Power Control (LDOPCTL) register.
Figure 5-4 on page 171 shows the power architecture.
Note: On the printed circuit board, use the LDO output as the source of VDD25 input. Do not use
an external regulator to supply the voltage to VDD25. In addition, the LDO requires decoupling
capacitors. See “On-Chip Low Drop-Out (LDO) Regulator Characteristics” on page 594.
VDDA must be supplied with 3.3 V, or the microcontroller does not function properly. VDDA
is the supply for all of the analog circuitry on the device, including the LDO and the clock
circuitry.
170
July 16, 2014
Texas Instruments-Production Data