Voltage Regulator Operation - Fujitsu MB96300 series Hardware Manual

MB96300 Super Series Hardware Manual CHAPTER 9 STANDBY MODE AND VOLTAGE REGULATOR CONTROL
9.7

Voltage Regulator Operation

The 16FX MCUs are equipped with an on-chip voltage regulator which generates the
power supply for the core logic out of the external power supply. This regulator has
different operation modes with programmable output voltage. This feature can be used to
optimize power consumption, especially in Standby modes.
This chapter describes the different operation modes of the regulator, how to change the
operation mode and how to set the output voltage.
■ High Power mode
The "High Power mode" is the default operation mode of the voltage regulator. In this mode, the regulator is
able to provide the maximum current consumed by the MCU in any mode. The output voltage for this mode
is individually programmable. The default output voltage is 1.8V (adjusted to the process technology) and the
current consumption of the regulator itself is several hundred microampere.
The voltage regulator is operating in this mode when either the RC oscillator or the Main oscillator is active
(unless the SMCR:LMPS or SMCR:LPMSS bits are set).
■ Low Power mode
The "Low Power Mode" is the alternative operation mode of the voltage regulator. In the Low Power Mode,
the regulator is able to provide a maximum transient current of ~100µA. The current consumption of the
regulator itself is reduced to ~10µA. No Flash programming/erasing is permitted in this mode.
Two different Low Power Modes are available. The output voltage for each mode is individually
programmable. The default output voltage for both modes is 1.8V:
●
Low Power Mode A
The voltage regulator is operating in this mode when the RC oscillator and the Main oscillator are both
stopped and the Sub oscillator is active (Sub Run/Sleep/Timer mode with disabled RC and Main oscillator).
This mode can also be selected by setting the SMCR:LPMS or SMCR:LPMSS bits even if the RC or Main
oscillator is enabled.
●
Low Power Mode B
The voltage regulator is operating in this mode when all oscillators are stopped (Stop mode).
This mode can also be selected by setting the SMCR:LPMBSS bit.
Note:
Selecting this mode using the SMCR:LPMBSS bit is currently under evaluation and must not be used.
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