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

Can AD8226 amplify more than its recommended max Gain?

Status
Not open for further replies.
tony_lth

tony_lth

Advanced Member level 5
Joined
Jul 28, 2010
Messages
2,086
Helped
377
Reputation
756
Reaction score
368
Trophy points
1,363
Location
Beijing
Activity points
12,623
Hi,
I used AD8226 to amplify a very small signal.
AD8226 datasheet says that its max Gain is 1000, determined by a external resistor, i.e. 50 ohms.
But my signal is still small after 1000 gain, can I reduce the resistor to 25 ohm so as to get 2000 gain?
I know this is out of the recommeded range by ADI, but I wonder what is the result of doing so, the IC　 is broken? Ot it can work?
Thanks.
 

Attachments

  • AD8226ARMZ_datasheet.pdf
    415.6 KB · Views: 62

Increasing the gain will increase the noise and the input offset voltage. Simply add another amplifier at its output (maybe another AD8226).
 
But that will increase the cost, so I wonder what is the max gain that AD8226 can get?
 

Its datasheet is published by its manufacturer and it says the max gain (with all spec's) is 1000. Don't you believe them or do you want poor spec's?
Simply add a cheap low noise opamp to its output. The extra amplifier does not need to be an expensive instrumentation amplifier.
 
Hi,

If you connect a low value resistor, then gain will increase. The Opamp won't get hurt.
The disadvantage is: lower frequency response, increased distortions, increased gain error.

But it will have less output noise than the two opamp solution and it will have less output offset than the two opamp solution (if both curcuits have the same overall signal gain). Almost independent of the second amplifier.

It depends on your specifications:
Signal frequency, waveform, source impedance, offset voltage, offset voltage drift, distortion, gain, gain error, phase shift, noise...

Klaus
 
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top