Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Diode connected load or current mirror

Status
Not open for further replies.

ICdesignerbeginner

Member level 5
Joined
Nov 22, 2017
Messages
86
Helped
1
Reputation
4
Reaction score
2
Trophy points
8
Activity points
729
Hi

I saw one figure of NMOS with current source. source source is replaced by diode connected load and in another circuit the current source is replaced by a current mirror. Which one is better. Can some one tell me the use of only diode connected load inplace of current source. (See attached figure, fig.1 is replaced by fig b or c

1.jpg)
 

It's a PMOS current source. their difference is their equivalent impedances. the diode connected load is simpler but it's small signal resistance is 1/gm (low impedance node) while for the one with a current mirror has a small signal resistance of ro (high impedance node). a higher impedance load gives a higher gain but needs a biasing circuit as shown. moreover, the diode connected load has a lower gain but is more linear because it's gain is dependent on the aspect ratio of the two transistors.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top