OLIMEX© 2015
STM32-P405 user's manual
6.5 PWR_JACK connector
The power jack used is the typical one used by Olimex in most of our products – the DC barrel jack has
2.0mm inner pin and 6.3mm hole. More information about the exact component might be found here:
https://www.olimex.com/wiki/PWRJACK
You should provide either (6 – 12)V direct current or (5 – 9)V alternating current. The required current
may vary depending on the peripherals connected to the board. Do not provide more than 12VDC! Do not
provide more than 9VAC!
PWR_JACK connector
Pin #
Signal name
1
Power input
2
GND
More info about the power supply can be found in chapter 4 of this manual.
6.6 BAT_3V connector
When using the battery connector keep in mind that it is an energy solution that wouldn't be able to power
the board and all the peripherals!
The board has BAT_3V connector which can be used to keep alive the RTC, external clock 32 kHz
oscillator and backup registers (through power switch) when VDD is not present. BAT_3V requires
voltage in the 1.65V – 3.6V range!
BAT_3V connector
Pin #
Signal name
1
VBAT
2
GND
The pin polarity is also printed near the connector.
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