PXR40RM Datasheet, PDF (133/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Chapter 5
Power Management Controller (PMC)
5.1 Introduction
The power management controller (PMC) is compatible with 3.3V or 5V operation. It provides voltage
regulation to the microcontroller and includes advanced power on reset (POR) and precision low voltage
detector (LVD) monitors that guarantee safe device operation.
5.1.1 Features
The PMC contains the following features (see Section 5.1.1.1, Analog PMC_SMPS features and
Section 5.1.1.2, Digital PMC_SMPS features for detailed analog and digital features of this device):
• Compatible for both 5V and 3.3V operations.
• A Switched Mode Power Supply (SMPS) Buck regulator and a Low Drop Out (LDO) linear
regulator, sharing the same control pin (REGSEL).
• SMPS regulator is selected when the REGSEL pin is connected to VDDREG. A 5V nominal suppy
voltage is recommended to operate and defines the LVD level to 5V.
• LDO regulator is selected when the REGSEL pin is connected to VSS. A 3V nominal suppy
voltage is recommended to operate and defines the VDDREG LVD level to 3V.
• High precision Low Voltage Detector (LVD) monitor for PMC supply voltage VDDREG, VDD
core voltage supply, and VDDSYN.
• A low voltage band gap generates the reference voltages and currents for voltage regulators and
LVDs.
• A Power On Reset (POR) monitor is used to check main regulator supply VDDREG and core
supply VDD and guarantees proper system function even at very low voltage supply levels.
• No power sequencing constraint required.
• An independent internal regulator generates 1.2V supply voltage for the low voltage digital portion
of the PMC.
• A 5V to 3.3V LDO regulator is enabled when the PMC is in SMPS5V mode and when the PMC is
in LDO mode with nominal supply voltage of 5V (LDO5V mode). The LDO 5V to 3V is disabled
when VDDREG is 3.3V nominal and in this case VDDREG and VDDSYN must be connected
together (LDO3V mode).
• A loose precision temperature sensor detects over-temperature conditions in the PMC and adjacent
area. Its low accuracy requires that temperature is checked with the included precision temperature
sensor before taking any corrective action.
• Direct measurement of PMC internal voltages is available at predefined ADC channels.
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
5-1