Current reference source for a 2 stage operational amplifier

[hobbyiclearner]

Hello,

Can anyone suggest a simple current reference circuit for a two stage op amp. I need to generate constant current in uA range to be injected in the diode connected transistor and mirrored at both the stages.

Thanks,
Hobbyiclearner

 

[AMSA84]

Do you need voltagem and temperatura indepedance?

 

[CMOS-Tangram]

Hi,

If you need a simple Current Source Reference independent of the supply voltage you can use the following scheme:



On the left the starting circuit is shown. The reference source circuit is on the right. Iref is the output current.

Greetings, I hope it meets your expectations.

 

[hobbyiclearner]

Are there any references for the above circuit. Any books / name of the ckt etc.

Thanks.

 

[CMOS-Tangram]

This circuit is discussed in chapter 4 of the book Analog Design for CMOS VLSI Systems / Franco Maloberti.

4.2.3 Self Biased Micro-Current Generator
4.2.4 Start-up Circuits

* There is an error in the above scheme. The correct scheme is attached.

 

[AMSA84]

In Bakers book you can find a good description and info avout this circuit.

 

[hobbyiclearner]

OK.. I will check them out and let you know.

Thanks,
Hobbyiclearner