Re: CD4013 Vdd?

From: Ken Smith (kensmith_at_green.rahul.net)
Date: 11/11/04 

Date: Thu, 11 Nov 2004 18:43:41 +0000 (UTC)

In article <b9OdneQGMJEBHw_cRVn-og@buckeye-express.com>,
Mark Jones <abuse@127.0.0.1> wrote:
[....]
> Thanks. Actually I'm looking for a way to switch on power to a
>PIC16LF876A design running from a single lithium ion AA battery
>(4.2v-2.5v.) The design only has one button, so a low-going signal
>must turn it on (and consume next to nothing when off.) I was
>wondering if a 4013 connected to Vdd and Vss via this button, could be
>turned on by the button (which then latches and powers up the PIC.) A
>MOSFET was also a consideration, great off resistance but it's hard to
>get good conduction with only 2.5v gate voltage. K.I.S.S...

How about this to get more gate drive?:

      Buffer
       !\
  -----! >---+--------->!-------+------+------------ Mosfetgate
       !/ / ! !
             \ --- /
             / --- \
             ! !\ ! /
             +----! >------------ !
             ! !/ GND
            ---
            ---
             !
            GND
     

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