Need for Current Mirror

Thread Starter

sivaraj

Joined Oct 8, 2007
6
Hai i am sivaraj.
* can any tell mi the function or how current mirror works exactly....
*diff. between PMOS and NMOS Current Mirror
 

Dave

Joined Nov 17, 2003
6,970
We have an article on current mirrors here at AAC however it focuses on BJTs: http://www.allaboutcircuits.com/vol_3/chpt_4/12.html

To quote: "A current mirror is a transistor circuit that regulates current through a load resistance, the regulation point being set by a simple resistor adjustment."

For the MOSFET current mirror, the fundamentals are the same however you need to be familiar with the analogies of BJTS and MOSFETS to use the above AAC section. The wiki on current mirrors will give you an appropriate insight: http://en.wikipedia.org/wiki/Current_mirror

The difference between a PMOS and NMOS current mirror is that in one implementation p-type MOSFETs are used as the active devices for mirroring and in the other implementation n-type MOSFETs are used as the active devices for mirroring.

I would suggest that you read the above articles and post back with specifics if you require further help.

Dave
 
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