Minimum voltage to PIC

[tomcody]

Hi everybody, I need to feed the CORE with less than 5V, let's say 4.5V or even less (the microchip page says operating range is 2 to 5.5V). I did some tests with a adjustable power supply and a PIC with just the bootloader. When the voltaje gets lower than 4.60V (4.59V) the CORE stops sending the request message :shocked: , I looked the PIC18F452 datasheet and there are the Low Voltage Detect Control register, LVDCON thats defines a voltaje range in which PIC gets interrupted if some bit are set. I've done a fast look in the code but didn't find LVDCON. Do I have to do some modification to the code to get the PIC working with a voltage lower than 4.6V?.

Thanks for any comment. :thumbsup:

TomCody.

[TK.]

Hi,

I've enabled the "brown out" reset circuit and set it to 4.5V to ensure that the PIC will be reset if the voltage drops below this level.

This ensures (for example) that IIC EEPROMs (BankSticks) are only accessed under proper working conditions - with lower voltages data stored in a BankStick could be unintentionally erased or overwritten.

So long you are not using devices which rely on this voltage, you can disable the Brown Out reset feature - this can only be done with a PIC programmer (see options screen of your PIC programming software)

Best Regards, Thorsten.

[tomcody]

That worked out. I've looked the 24LC256 datasheet and says the operating range is: 2.5-5.5V. The reason why Vcc>4.5V is a clock speed issue? If so the 24C04 for the GM5 chip also need Vcc>4.5V?

Thank you TK.

TomCody.

[TK.]

There wasn't an issue with Microchip EEPROMs (24LC), but with others so far I remember.

Best Regards, Thorsten.