Opamp recommendaion please

Thread Starter

cork_ie

Joined Oct 8, 2011
428
Hello all.
My latest project(plaything) is a 3 axis +/- 3g accelerometer based on the ADXL330.
I am using a board with a 3.3V power supply. 0g on each axis is approximately half that, 1.66 V , my maximum range is going to be 0V to 3.3V. signal on each output.
My Board specs are:
Triple axis =/-3g sense range.
Upto 360mV/g sensitivity
500Hz bandwidth
Internal 3.3V regulator
External operating voltage 3.5V to 15V
Integrated power supply decoupling
Draws 0.9mA
Can accurately drive 500Ohm Loads


What I would like to do is use a suitable OpAmp so that I can offset 0g to 0Volts and also amplify my signals so the output voltage range would be close to +/- 5V , i.e. + 3g=5V 0g=0V -3g=-5v . My outputs will normally be feeding 3 channels of my 4 channel Picoscope
Datasheet attached

Can anyone recommend a suitable low noise Opamp, ideally one that can handle all three inputs.
 

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Last edited:

ronv

Joined Nov 12, 2008
3,770
You will need to buffer the output of the 330 with a unity gain buffer. The output is really pretty high so I wouldn't worry to much about a real low noise amplifier. You can then follow the buffer with a gain of 1.5 or so. Reference the + input of the amplifier to a voltage divider of 1/2 Vcc. If you want it real accurate you may need a pot on this divider to zero out the initial error of the 0 G output of the 333. Plus and minus 15 volt supplies and something like two TL083's should work pretty good.
 
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