Talk:Widlar current source

Latest comment: 4 years ago by Hansschulze in topic Design procedure with specified currents

DC current mirror edit

Reference has been moved so link is no longer valid. —Preceding unsigned comment added by 75.82.213.125 (talk) 20:49, 11 April 2008 (UTC)Reply

Source versus mirror edit

After some careful analysis of the Widlar current source, I came to the conclusion that the this circuit is called source rather than mirror because the two currents on each branch of the circuit do not match. If I try to match the currents in both branches, I obtain an emitter resistance of 0Ω which is reducing the circuit to the simple current mirror. Does all this make sense or am I saying something stupid?

ICE77 (talk) 19:43, 24 May 2011 (UTC)Reply

I get the same, even negative resistances for some configs.

Hansschulze (talk) 00:59, 6 August 2019 (UTC)Reply

Design procedure with specified currents edit

I tried to get IO=5uA, IR1=10uA (best error%) in LTSpice and IR2=4.997uA while IO=4.869uA. Looks to me like 129nA of base current isn't accounted for in the right place. I would prefer that IO gets 4.997uA and IR2 = IO + IQ2B. But I ain't smart enough to fix the formula.

Hansschulze (talk) 01:57, 6 August 2019 (UTC)Reply