Circuit converter from 1A down 10mA

tom66

Joined May 9, 2009
2,595
The \(I_{out}\) for a LM334 is given by:

\(I_{out} = \frac{1.25V}{R_{set}}\)

At least that's what the datasheet says, minus bias currents.

So for \(R_{set}\) = 1.2kOhm...

\(I_{out} = \frac{1.25V}{1200} = 1.042mA\) to 4 d.p.

Unless I'm missing something.
 
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tom66

Joined May 9, 2009
2,595
I'm reading page 5, calculating \(R_{set}\). \(V_r\) is supposed to be 1.25V isn't it?

I see the graph and it makes sense to me. I guess I'm still thinking of the LM317. Thinking about it... why wouldn't an LM317 do the job anyway?
 

Ron H

Joined Apr 14, 2005
7,063
I'm reading page 5, calculating \(R_{set}\). \(V_r\) is supposed to be 1.25V isn't it?

I see the graph and it makes sense to me. I guess I'm still thinking of the LM317. Thinking about it... why wouldn't an LM317 do the job anyway?
LM334, at 25C, Vr=67.7mV.
LM317 Vref is only guaranteed for I>10mA. I think we already thrashed that one several pages back.
 
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