MPC5644B View Datasheet(PDF) - Freescale Semiconductor
Part Name
Description
MFG CO.
'MPC5644B' PDF : 114 Pages View PDF
4.8 Power management electrical characteristics
4.8.1 Voltage regulator electrical characteristics
The device implements an internal voltage regulator to generate the low voltage core supply VDD_LV from the high voltage
supply VDD_HV_A. The following supplies are involved:
• HV: High voltage external power supply for voltage regulator module. This must be provided externally through
VDD_HV_A power pin.
• LV: Low voltage internal power supply for core, FMPLL and Flash digital logic. This is generated by the on-chip
VREG with an external ballast (BCP68 NPN device). It is further split into four main domains to ensure noise isolation
between critical LV modules within the device:
— LV_COR: Low voltage supply for the core. It is also used to provide supply for FMPLL through double bonding.
— LV_CFLA0/CFLA1: Low voltage supply for the two code Flash modules. It is shorted with LV_COR through
double bonding.
— LV_DFLA: Low voltage supply for data Flash module. It is shorted with LV_COR through double bonding.
— LV_PLL: Low voltage supply for FMPLL. It is shorted to LV_COR through double bonding.
100 nf
100 nf
100 nf
VDD_LV VSS_LV VDD_LV VSS_LV VDD_LV VSS_LV
40 f
(4 10 f)
(CREGn)
PD1 Switchable Domain
(FMPLL, Flash)
PD0 (always on domain)
32 KB 56 KB
Split Split
8 KB
Split
Off chip
BCP68
NPN driver
VDD_LV
VSS_LV
VRC_CTRL
10 f
HPREG
HPVDD
LPVDD
LPREG
sw1 (<0.1)
CTRL CTRL
CTRL
(CDEC2)
VDD_BV
Chip Boundary
VDD_HV_A
VSS_HV
HPVDD
LPVDD
100 nf
Figure 8. Voltage regulator capacitance connection
The internal voltage regulator requires external bulk capacitance (CREGn) to be connected to the device to provide a stable low
voltage digital supply to the device. Also required for stability is the CDEC2 capacitor at ballast collector. This is needed to
minimize sharp injection current when ballast is turning ON. Apart from the bulk capacitance, user should connect
MPC5646C Microcontroller Data Sheet, Rev. 3
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
55
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