can a capacitor instead of battery be used on pin VBACKUP for backup purpose?

Jiansheng Liu

Other Parts Discussed in Thread: TPS65910

I wonder if it is possible to use a capacitor instead of battery connecting to pin TPS65910's VBACKUP for temperary backup purpose? I don't expect it is able to last for ever, but just for a few of minutes. Is it possible? If it is how big a capacitor be considered? There is a capacitor in range of 5-2000mF attached to this pin in TPS65910's user guide (page 2 of SWCU078 - Oct 2010). Is it for this purpose?

2nd question: if we don't need backup, can this pin be left open or a capacitor still be needed?

thanks for help!

over 14 years ago

0 Gandhar Dighe over 14 years ago

TI__Genius 15100 points

Hi,

1. Yes, you can use a capacitor. The value will really depend on how long you want the capacitor to hold charge.

2. You should ground the pin if backup is not required.

Regards,

Gandhar.

0 Jiansheng Liu over 14 years ago in reply to Gandhar Dighe

Intellectual 310 points

Thanks for the reply. I checked the datasheet that describes a capacitor in a range of 5 to 2000mF, that is huge! Are we sure it is not a typo of 5 to 2000uF?

0 Davey Thomas over 12 years ago in reply to Gandhar Dighe

Intellectual 255 points

Hi Gandhar,

I know this is an old post but from #2 above you state that VBACKUP (pin 27) should be grounded if backup is not required. The TPS65910 datasheet pg. 37 states that if VBACKUP (pin 27) is not used it should be shorted to VCC5 (pin 23). Which is the preferred method?

0 Flore Auzanneau over 12 years ago in reply to Davey Thomas

TI__Intellectual 1820 points

Hello,

Jiansheng Liu, there is no typo.

Davey Thomas, please refer to TPS65910 Schematic checklist (SWCA139)

Best regards,

Flore

0 Frank S. over 11 years ago in reply to Gandhar Dighe

Prodigy 90 points

Hi Gandhar,

is it possible to use a 10F/2.5V SuperCap with the TP65910A1 register setting BBCH_REG = 0x03?

Regards,

Frank

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can a capacitor instead of battery be used on pin VBACKUP for backup purpose?