Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Low offset, low noise op amp recommendation

Status
Not open for further replies.

Oznog

Active Member
I have a couple of silicon strain gauge pressure sensors which are inherently quite noisy (500Hz - MHz range), but I must have a high accuracy reading out of a 16 bit op amp. Oversampling was not helpful enough, so I need to construct a lowpass filter, but the ADC will have an unacceptable loss of accuracy with the high source impedance.

So, I need to add a 1:1 buffer after the filter. It needs to be as low offset as possible, as well as low noise since the whole point is to lower the noise.

It's powered by a single 5v supply and the signal on one sensor swings to 4.1, but the other can swing to 4.95v, which may mean I need to select another sensor since fewer buffers can go rail-to-rail in 5v (voltage dividers are bad for accuracy so I will be staying away). Power output and supply current are not an issue.

Any recommendations? There's just a crapload of op amps out there and I'm going to looking through specs for awhile.
 
Oznog said:
I have a couple of silicon strain gauge pressure sensors which are inherently quite noisy (500Hz - MHz range), but I must have a high accuracy reading out of a 16 bit op amp. Oversampling was not helpful enough, so I need to construct a lowpass filter, but the ADC will have an unacceptable loss of accuracy with the high source impedance.

So, I need to add a 1:1 buffer after the filter. It needs to be as low offset as possible, as well as low noise since the whole point is to lower the noise.

It's powered by a single 5v supply and the signal on one sensor swings to 4.1, but the other can swing to 4.95v, which may mean I need to select another sensor since fewer buffers can go rail-to-rail in 5v (voltage dividers are bad for accuracy so I will be staying away). Power output and supply current are not an issue.

Any recommendations? There's just a crapload of op amps out there and I'm going to looking through specs for awhile.

A couple low noise choices to consider.

LT1028 / LT1037 from linear.com

OP184 from analog.com

OPA228 from ti.com

LM833 from national.com (very nice cost)

MAX4475 from maxim-ic.com

Happy hunting!
 
When you say oversampling, does that mean you already tried software-based filtering?
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top