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.

Register Log in

[SOLVED] More current from multi channel opamp buffer

Status
Not open for further replies.
Z

Zak28

Advanced Member level 2
Joined
Aug 19, 2016
Messages
579
Helped
6
Reputation
12
Reaction score
6
Trophy points
18
Activity points
4,681
Would ganging all channels of an LM324 to buffer +/-5v from a dual supply ~25mA per channel cause its high frequency performance to drop? There are specialty buffer opamps but I only need =<1Mhz. This is to measure parasitics of coils and transformers.
 

Consider that paralleled OPs will work against each other due to input offsets, drawing excessive current form the power supply.
 
  • Like
Reactions: Zak28

    Z

    Zak28

    Points: 2
    Helpful Answer Positive Rating
Agree but shouldn't be too hard to fix. 1 ohm balancing resistor means 1mA current imbalance assuming 1mV offset while adding 20mV output voltage variation over 20mA load. Maybe that's fine?

Or gang together 3 opamps with balancing resistors and use the 4th opamp to regulate their output (cascade costs some bandwidth).

But yes, buying an appropriate buffer amplifier may be the best choice. Be careful with opamp current specs too, many specify typical output current, not minimum.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top