Re: Favourite circuits for CC generator ?

From: ChrisGibboGibson (chrisgibbogibson_at_aol.com)
Date: 09/30/04 

Date: 30 Sep 2004 23:41:18 GMT

"Fred Bartoli" wrote:

>> Thanks. I'll turn it upside down tomorrow and try it as a source. I can
>ensure
>> the 10/15V is within 10mV quite easily.
>>
>> Looks too easy to true to me though :)
>>
>
>Yeah, just simulated it and gives you 6nA stability for 6V supply variation.
>This is an easy 1Gohm :-)
>
>You can reduce the 15V sensitivity by a 10-15 time factor at the expense of
>an additionnal transistor :
>
>
> |
> 10K 2.2K |
> ___ ___ |
> +15V -|___|--+---|___|----. |
> | | ||-+
> >| | ||<-
> |----------+---||-+
> /| | |
> | ' |
> | \| |
> === |----+
> GND <| |
> | .-.
> | | |
> | | |470
> | '-'
> | |
> | |
> === ===
> GND GND
>
>created by Andy´s ASCII-Circuit v1.22.310103 Beta www.tech-chat.de
>
>This has also the nice effect of increasing the output resistor by almost
>three time (loop gain is increased by the constant current collector load).
>

That's a neat trick but I just simulated the first one and that's plenty good
enough.

Cheers

Gibbo