THANS! The LM134 DOES look interesting.

Harold


> Harold Hallikainen wrote...
>
>>I'm loooking for a two terminal constant current device that could be put
>>between an LED and a variable DC supply to hold the LED current at 5mA as
>>the supply varies over a 0-10V range (recognizing we're not going to get
>>it at 0V, but I'd like the widest range possible). So far i've found the
>>Central Semiconductor CCLM5750 which is a nominal 5.750mA, but it takes
>>4.5V to get 80% of the rated current. Anyone have other ideas?
>
> How about NSC's LM134?  It's actually billed as a temperature
> sensor because its current output is proportional to absolute
> temperature; but it seems to me that would be an advantage in
> this application as it would tend to offset the LED's somewhat
> negative temperature dependence.
>
> AFAIK the LM134 requires about 1 volt of headroom to operate.  A
> current programming resistor is also required; for 5 mA the value
> would be about 12 ohms.
>
> HTH...
>
> Dave D.
>
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