2012-06-06 06:59 AM
Hi,
I'm working on a custom design with in a STM32F4xx. A 420mF capacitor is connected to Vbat. ( with a serial diode and a resistor between Valim and Vbat to charge up the supercapacitor ).The system power off it still 600mV to Valim if the supercapacitor is connected, 0V if not.So I'm a bit confused,...Any ideas ?Thanks, #vbat2012-06-06 10:54 AM
Sounds familiar, suggest you call your FAE/rep if you want an answer from ST.
https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Vdd being held at 0.7V with backup battery fitted&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B¤tviews=96
2012-06-07 01:25 AM
Ok thank's.
2012-06-11 08:02 AM
Any more information on this please? IS there a problem with the VBat switching / power leakage on the STM32F4 chip?
2012-11-12 09:46 AM
hello,
Problem solved ! Please see:https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Vdd being held at 0.7V with backup battery fitted&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B¤tviews=449
2012-11-13 01:41 AM
Hi PAM,
Thanks for completing this post. For everyone else (after the system crashes and all the links break) the message was,''I get it ! In my design PDR_ON was left unconnected. If i pull it up; this probleme is solved !''
Hope that's it!.