NXP Semiconductors MPC5566 - External Signal Description

Voltage Regulator Controller (VRC) and POR Module
MPC5566 Microcontroller Reference Manual, Rev. 2
23-2 Freescale Semiconductor
23.2 External Signal Description
Table 23-1 describes the VRC signals.
23.3 Memory Map and Register Definition
The VRC and POR module have no memory-mapped registers.
23.4 Functional Description
The VRC portion of the module contains a voltage regulator controller, and the POR portion contains
circuits to monitor the voltage levels of the 1.5 V and V
DDSYN
power supplies, as well as circuits to
monitor the power supply for the RESET pad. The PORs indicate whether each supply monitored is above
the specified voltage threshold. The PORs ensure that the device is correctly powered up during a
power-on reset. POR holds the device in reset when any of the monitored supplies fall below the specified
minimum voltage.
23.4.1 Voltage Regulator Controller
The VRC circuit has a control current for use with an external NPN transistor and an external resistor to
power the 1.5 V V
DD
supply. The control current is output on the V
RCCTL
pin. The voltage regulator
controller slowly turns on the pass transistor while the 3.3 V POR is asserted. The pass transistor is
completely turned on by the time the 3.3 V POR negates.
Table 23-1. Voltage Regulator Controller and POR Block External Signals
Signal Type Signal Level Description
V
RC33
Supply pin 3.3 V Regulator supply input. 3.3 V VRC supply input.
V
DDSYN
Supply pin 3.3 V FMPLL supply input. This is the 3.3 V supply input for the frequency
modulated phase lock loop (FMPLL) module.
V
DDEH6
Supply pin 3.3–5.0 V RESET pin supply input. Power supply input for padring segment that
contains the RESET pad.
V
RCVSS
Supply pin 0.0 V Regulator supply ground. V
RCVSS
is the 3.3 V ground reference for the
on-chip 1.5 V regulator control circuit.
V
RCSNS
1.5 V sense 1.5 V 1.5 V sense used by VRC. Pad connected to V
DD
plane in package—not a
package ball. This is the 1.5 V sense from the external 1.5 V supply output
of NPN transistor. This input is monitored by the VRC to determine the value
for V
RCCTL
. V
RCSNS
is a pad on the die that is connected to a V
DD
plane
inside the package. It is not a package ball.
V
RCCTL
Current output — Regulator control output. The V
RCCTL
sources base current to the external
bypass transistor. The V
RCCTL
signal is used with internal and external
transistors to provide V
DD
, which is the MCU 1.5 V power supply.
V
DD
Supply pin 1.5 V Internal 1.5 V power supply input.