Reset and power supply supervisor
AN4488
16/50
AN4488 Rev 7
Note:
Please contact your local STMicroelectronics representative or visit
www.st.com
in case you
want to use circuitry different from the one described hereafter.
Restrictions:
•
PDR_ON = 0 is mostly intended for V
DD
supply between 1.7 V and 1.9V (i.e. 1.8V +/-
5% supply).
Supply ranges which never go below 1.8V minimum should be better managed with
internal circuitry (no additional component thanks to fully embedded reset controller).
•
To ensure safe power down, the external voltage supervisor (or equivalent) is required
to drive PDR_ON=1 during power off sequence.
When the internal reset is OFF, the following integrated features are no longer supported:
•
The integrated power-on reset (POR) / power-down reset (PDR) circuitry is disabled.
•
The brownout reset (BOR) circuitry must be disabled.
•
The embedded programmable voltage detector (PVD) is disabled.
•
V
BAT
functionality is no more available and V
BAT
pin should be connected to V
DD
.
Figure 7. PDR_ON simple circuitry example (not needed for STM32F410xx,
STM32F411xx, STM32F413xx, STM32F423xx, STM32F412xx, STM32F446xx,
STM32F469xx and STM32F479xx)
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