MPC5604B/C Microcontroller Reference Manual, Rev. 8
Freescale Semiconductor 223
Chapter 11
Voltage Regulators and Power Supplies
11.1 Voltage regulators
The power blocks provide a 1.2 V digital supply to the internal logic of the device. The main supply is
(3.3 V–5 V ± 10%) and digital/regulated output supply is (1.2 V ± 10%). The voltage regulator used in
MPC5604B comprises three regulators.
• High power regulator (HPREG)
• Low power regulator (LPREG)
• Ultra low power regulator (ULPREG)
The HPREG and LPREG regulators are switched off during STANDBY mode to save consumption from
the regulator itself. In STANDBY mode, the supply is provided by the ULPREG regulator.
In STOP mode, the user can configure the HPREG regulator to switch-off (Refer to MC_ME chapter). In
this case, when current is low enough to be handled by LPREG alone, the HPREG regulator is switch-off
and the supply is provided by the LPREG regulator.
The internal voltage regulator requires an external capacitance (CREG) to be connected to the device in
order to provide a stable low voltage digital supply to the device. Capacitances should be placed on the
board as near as possible to the associated pins.
The regulator has two digital domains, one for the high power regulator (HPREG) and the low power
regulator (LPREG) called “High Power domain” and another one for the ultra low power regulator
(ULPREG) called “Standby domain.” For each domain there is a low voltage detector for the 1.2 V output
voltage. Additionally there are two low voltage detectors for the main/input supply with different
thresholds, one at the 3.3 V level and the other one at the 5 V level.
11.1.1 High power regulator (HPREG)
The HPREG converts the 3.3 V–5 V input supply to a 1.2 V digital supply. For more information, see the
voltage regulator electrical characteristics section of the data sheet.
The regulator can be switched off by software. Refer to the main voltage regulator control bit (MVRON)
of the mode configuration registers in the mode entry module chapter of the reference manuals.
11.1.2 Low power regulator (LPREG)
The LPREG generates power for the device in the STOP mode, providing the output supply of 1.2 V. It
always sees the minimum external capacitance. The control part of the regulator can be used to disable the
low power regulator. It is managed by MC_ME.
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