Hi Robert,

I don't think there are any protection diodes (or at least, none to Vdd) on
RA4, just because of this. In addition, there is no way the chip could go
into melt down through a 10K resistor. 

Sean

At 10:02 PM 7/5/99 -0700, you wrote:
>        Probable the results would be rather catastrophic, There is a
200ľa limit
>in current injected into any pin. If for ANY reason the protection diodes
>are forward biased the chip will go into melt down. This comdition has been
>known to burn labels off of 'JW' parts... One of the sure ways to destruct
>a chip.
>
>                Robert K. Johnson
>                rkj1@ix.netcom.com
>
>At 04:30 PM 7/5/99 +1000, you wrote:
>>Hi....
>>
>>I'm interfacing a 16F84 to a 4051 analog mux with a 12V supply.
>>Is it safe to put a 10k pullup resistor to +12V from the open drain output
>>RA4?.
>>
>>
>>Thanks
>>Stewart.
>
|
| Sean Breheny                   
| Amateur Radio Callsign: KA3YXM 
| Electrical Engineering Student  
\--------------=----------------
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