1 Power supply

AN2202

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Figure 2.

Power management block

Note:

* Disconnected in LPWFI mode.

Main Voltage Regulator (MVR)

In normal operation, the Main Voltage Regulator (MVR) provides the 1.8V supply.

The MVR can be switched off when entering a low power mode (refer to Section 3)

When the MVR is switched off, the Low Power Voltage Regulator (LPVR) can provide a power

supply of about 1.8V (+/- 10%).

Note: 1 The MVR has a static power consumption of 3.97 mA typ at 25°C.

2 When the MVR is switched off, The PLL is automatically disabled (PLL off) and the maximum

allowed operating frequency is 2 MHz, this is due to the limitation imposed by the LPVR which

is not able to generate sufficient current to operate in run mode.

1.2.1

Low Power Voltage Regulator (LPVR)

The Low Power Voltage Regulator (LPVR) is used when the MCU is in low-power mode and the

main voltage regulator has been switched off. It has a different design from the main voltage

regulator and generates a stabilized and thermally-compensated voltage in the range of 1.8V

(+/- 10%), its output current is not generally sufficient for the device to run in normal operation.

A/D converter

Memory and I/Os

V18

Note*

Main Voltage Regulator

Low Power Voltage Regulator

Core and Peripherals

Peripherals active

in LPWFI mode

V18