PXD20RM Datasheet, PDF (1574/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

• Ultra low power regulator (ULPREG)
The HPREG and LPREG regulators are switched off in STANDBY mode to save power consumption by
the regulator itself. During STOP and HALT modes only, the HPREG regulator may be switched off. The
ULPREG regulator is always kept on.
The internal voltage regulators require an external capacitance to be connected to the 1.2 V supply pins in
order to provide a stable low voltage digital supply to the device. Capacitances should be placed on the
board as near as possible to the associated pins.
The regulator has two digital domains, one for the main regulator (HPREG) and the low power regulator
(LPREG) called the “High Power domain,” and one for the ultra low power regulator (ULPREG) called
the “Standby domain.” For each domain there is a low voltage detector (LVD) for the 1.2 V output voltage
(ULVDD and MLVDD). Additionally, there are two low voltage detectors for the main/input supply with
different thresholds, one at 3.3 V (ULVDM), the other at 5 V (ULVDM5).
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PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor