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.

CMOS Current Operational Amplifiers

Status
Not open for further replies.

Eknath

Newbie level 4
Joined
Sep 30, 2012
Messages
7
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,329
I want to implement a Current operational Amplifier(COA), I have difficulty in finding the applications where COA are used. I want some references that can explain the applications of COA in detail and not just in one line.
 

erikl

Super Moderator
Staff member
Joined
Sep 9, 2008
Messages
8,112
Helped
2,694
Reputation
5,368
Reaction score
2,293
Trophy points
1,393
Location
Germany
Activity points
44,063
I think it's the same as an Operational Transconductance Amplifier (OTA), e.g. CA3080 (from TI, Intersil): relatively low input impedance and high output impedance, both (together) programmable. Search for their dataSheets and application notes!
 

LvW

Advanced Member level 5
Joined
May 7, 2008
Messages
5,853
Helped
1,745
Reputation
3,494
Reaction score
1,345
Trophy points
1,393
Location
Germany
Activity points
39,476

erikl

Super Moderator
Staff member
Joined
Sep 9, 2008
Messages
8,112
Helped
2,694
Reputation
5,368
Reaction score
2,293
Trophy points
1,393
Location
Germany
Activity points
44,063
I think the OTA is a controlled current source with a high input resistance (with other words: A voltage-to-current converter).

I think the CA3080 isn't far away from being called a COA, too: its input resistance is relatively low compared to that of an OpAmp: see p.2 of its dataSheet:

Anyway, thanks for the COA paper link!
 

Attachments

  • CA3080_p2.pdf
    61.8 KB · Views: 11

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
48,924
Helped
14,335
Reputation
28,934
Reaction score
13,083
Trophy points
1,393
Location
Bochum, Germany
Activity points
282,298
I don't see CA3080 related to current mode amplifiers. It's a basic bipolar OTA, exposing a differential pair with respective low input resistance. Implementing a basic OTA in CMOS gives similar behaviour with high input resistance.
 
  • Like
Reactions: LvW

    LvW

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top