Voltage Regulator Controller (VRC) and POR Module
MPC5566 Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 23-5
Figure 23-3. Voltage Regulator Controller Hookup
NOTE
Do not use Figure 23-3 as a reference for board design. Refer to Application
Note AN3254 for resistor requirements.
23.5.2 Compatible Power Transistors
The following NPN transistors are compatible with the on-chip VRC:
• ON Semiconductor
TM
NJD2873
• Phillips Semiconductor
TM
BCP68
Refer to the MPC5566 Microcontroller Data Sheet for information on the operating characteristics.
23.5.3 Power Sequencing Requirements
This section describes the following power sequencing requirements for the device:
• If an external 1.5 V power supply is used and V
RC33
is tied to ground, power sequencing is required
between the 1.5 V power supply, and V
DDSYN
and the RESET power supplies. To avoid this power
sequencing requirement, power up V
RC33
within the specified operating range, even if not using
the on-chip voltage regulator controller.
Refer to Section 23.5.3.1, “Power-Up Sequence If V
RC33
Grounded” and Section 23.5.3.2,
“Power-Down Sequence If V
RC33
Grounded.”
• The V
DD33
voltage must be high enough before POR negates to ensure the values on certain pins
are treated as 1s when POR negates.
Refer to Section 23.5.3.3, “Input Value of Pins During POR Dependent on V
DD33
.”
MCU
V
RC33
V
RCCTL
V
DD
V
RCVSS
Note AN3254 for
resistor requirements.
Refer to Application
1
1
This is the digital Vss
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