help on nested op-amp

[nanock]

hi friends,
look at this nested op-amp. it seems there is a problem on current source generator, q800-q850.
the problem is " IB>IC".
also this is hspice results.How can i solve it?
https://obrazki.elektroda.pl/40_1306698864.jpg

 

[Prototyp_V1.0]

Yes. It's very odd.

Given Vcc is 12V. Then, voltage over R800 would be around 10.5V.

Also you got Ib>Ic is obvious - assuming you're talking about Q800. I'll guess you could solve this by adding a resistor in between vcc and Q850.
I haven't seen a current mirror like that before.

 

[nanock]

hi,
what is the magnitude of this resistor?

 

[Prototyp_V1.0]

hi,
what is the magnitude of this resistor?

What resistor?

 

[nanock]

What resistor?

you've told:" I'll guess you could solve this by adding a resistor in between vcc and Q850."
so that?

 

[Prototyp_V1.0]

you've told:" I'll guess you could solve this by adding a resistor in between vcc and Q850."
so that?

Problem is, I haven't seen that kind of curent mirror before so I would be a bit carefull to say it actually would work.

If it was up to me, I would have draw the whole current mirror from scratch.

 

[mstealth]

Thanks for this post and I was also facing such problem.