On Sun, 23 Jan 2005 19:13:43 -0800, you wrote:

>
>Hi to all engineers,
>
>I am working on portable application where I need
>to use 9 volt battery with pic and on/off keypad.
>my question is if I use 5 volt regulator in off condition it will
>drain the battery if I completely turn it off how
>can I turn it back on there is no standby voltage
>any idea? will highly appreciate.
>
>Andre   

Use a micropower regulator. e.g. Holtek HT7150 - about 1-2 microamps for the regulator and a few
tens of uA for the PIC, less if WDT is disabled. 
There are several other micropower regulators available - I think Micorchip inherited some from the
old Telcom line, plus some from seiko, ricoh and OnSemi (78lcxx)


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