Bob,

Wow......interesting!

Thanks,
Mark

Bob Blick wrote:
> On Fri, 12 Mar 2010 11:39:21 -0600, "Mark E. Skeels" said:
>   
>> I am working on a mixed signal system and I need to generate a smallish 
>> negative voltage, (say -1V or so) for use as a negative op 
>> amp/comparator supply to overcome problems like comparators not swinging 
>> to ground, etc.
>>
>> In the past, I have used ICL7660's or National LM2687, both work well; 
>> solid enough and quiet enough, but they seem like overkill....does 
>> anybody have a favorite, simple solution for something like this?
>>     
>
> Hi Mark,
>
> An unusual way is either with a photovoltaic optoisolator, or else use a
> photodiodeor two with LED illumination. I know it's seems sort of
> byzantine but it'll keep clocks out of your circuit.
>
> Cheerful regards,
>
> Bob
>
>
>
>   
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