DV
CC
Voltage
SVS
H_IT+
SVS
H_IT-
Time
BOR
PMM Operation
85
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Power Management Module (PMM) and Supply Voltage Supervisor (SVS)
2.2
PMM Operation
2.2.1 V
CORE
and the Regulator
DV
CC
can be powered from a wide input voltage range, but the core logic of the device must be kept at a
voltage lower than what this range allows. For this reason, a regulator (LDO) has been integrated into the
PMM. The regulator derives the necessary core voltage (V
CORE
) from DV
CC
.
The regulator supports different load settings to optimize power. The hardware controls the load settings
automatically, according to the following criteria:
•
Selected and active power modes
•
Selected and active clocks
•
Clock frequencies according to Clock System (CS) settings
•
JTAG is active
In addition to the main LDO, an ultra-low-power regulator (RTC LDO) provides a regulated voltage to the
real-time clock module (including the 32-kHz crystal oscillator) and other ultra-low-power modules that
remain active during LPM3.5 when the main LDO is off.
2.2.2 Supply Voltage Supervisor
The high-side supervisor (SVSH) oversees DV
CC
. It is activate in all power modes by default. To disable
the SVSH in LPM3, LPM4, LPM3.5, and LPM4.5, set SVSHE = 0.
2.2.2.1
SVS Thresholds
As
shows, there is hysteresis built into the supervision thresholds, such that the thresholds in
force depend on whether the voltage rail is going up or down.
The behavior of the SVS according to these thresholds is best portrayed graphically.
shows
how the supervisors respond to various supply failure conditions.
Figure 2-2. Voltage Failure and Resulting PMM Actions