Robin Wang

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9 years, 12 months ago.

How to power the LPC11u24 using Batteries?

Hi,

I used to use 9V battery( the actual voltage is 8.7V) and it worked well during the test. But the 11u24 suddenly stopped working after that for certain reason I dont know... Therefore I am very cautious with battery power. Can anyone please tell me how to use batteries to power up the LPC11u24?

Thank you!

2 Answers

Erik -
9 years, 12 months ago.

Using a roughly 3V battery directly on Vbat is ideal. But a 9V battery on Vin should not be a problem.

Paul Staron
9 years, 12 months ago.

For battery use after programming, use 3.3v on the VB pin. This will bypass the MBED IC and drop the power to 1 -16 mA. If your mbed has stopped working on USB there is another problem. Make sure you do not exceed 3.3v on the VB pin as there is no regulator or over voltage protection to the LPC11u24 MCU and it will certainly damage the chip.

Thanks Paul. It did stop working even on USB, once it is supplied by battery, the upper left of the MBED IC is very hot(I think that might be a regulator), does that mean it is indeed dead? Any idea of how could that happpen? I was so confused everything went very well and the next day, nothing changed, the MCU is dead... Thank you!

posted by Robin Wang 22 Apr 2014