Power Management Controller (PMC)
Freescale Semiconductor
5-17
PXR40 Microcontroller Reference Manual, Rev. 1
The bond diagram and over voltage protection is shown in
. Core LVD and flash supply are
provided by pad VDD33, which is also the default feedback signal for the 3.3V regulator loop. A high
voltage detect comparator switches the feedback point from VDD33 to the regulator output VDDSYN in
the event that this node raises above its maximum rating value, forcing the regulator to correct its DC point.
This feature protects the circuitry connected to the internal 3.3V supply in any event which disconnects
VDD33 and VDDSYN (e.g. a board failure or a bond wire failure).
Figure 5-6. 3.3V Regulator power connection
Tolerance of the 3.3V regulator, reported in the
PXR40 Microcontroller Data Sheet
, assumes appropriate
decoupling capacitance on VDDSYN pin, maximum current load less than or equal to IDD33, and a
correct board layout with reduced parasitics. It excludes line and load variation above 10 kHz.
The regulator output voltage, VDD33OUT, is adjustable via software by writing to the field VDD33TRIM
of the correspondent trimming register PMC_TRIMR, which selects one of the 16 voltages spaced at
STEPV33 step and available through the relative resistor chain. The reset value of the 4-bit register is
“1111”.
5.5.5
3.3V VDDSYN LVD
A user programmable low voltage detector (LVD) monitors the voltage VDDSYN.
Rising LVD threshold voltage is documented under LVD33 symbol in the
PXR40 Microcontroller Data
Sheet
.
Flash
Internal 3.3V
Supply
VDDREG
Vreg 3.3
Vbg
VDDREG
Vreg 1.2
VDDSYN
VDD33
R
R
R
R
Vbg
R
LVD Core
+
-
Summary of Contents for PXR4030
Page 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Page 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
Page 40: ...PXR40 Microcontroller Reference Manual Rev 1 xl Freescale Semiconductor...
Page 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Page 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
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