Hello,
I am looking for suggestions here for my circuit. I have a 3 Wheatstone bridge, 3 instrumentation amplifiers (INA333), One 24-bit ADC (ADS1220) sampling those INA333 outputs at 1000 SPS.
Here is the design and signal flow of the circuit for the result I have uploaded in attachments:
my circuit operates at 3.3V from a laboratory dedicated power supply.
1. I have used OPA333 to set the reference of INA333 at the mid supply of 1.65 V(since I am using a potentiometer to set voltage divider to set mid supply for OPA333 input there is some shift I belive in mid supply due to human hand error)
2. 3 INA333 inputs at grounded since my strain gauge is not yet ready to have experimented hence the voltage difference between inputs should be zero(theoretically).
3. I get the ADC input from ina333 outputs and the reference of ADC is power supply reference that is 3.3 V hence ratiometric measurements.
4. Now I have separated the power supply of ANALOG and DIGITAL part of ADC in order to separate noise to a certain degree but still, I am getting noise of 0.7 amplitude at mid supply
I have not got my hands on LP5907 component yet but I have i have included it in the cirucuit( please consider that the plot I got was from two seperate power supply in laboratory which will be replace with LP5907 once I get them)
And Yes I am right now using breadboard to prototype my circuit hence capacitance can be of significane?
Here is attached image of result of above mentioned circuit conditions and schematics.
It would be great if I could remove noise in order to use full 24bit(20bit ) of ADC resolution, thank you.
I am looking for suggestions here for my circuit. I have a 3 Wheatstone bridge, 3 instrumentation amplifiers (INA333), One 24-bit ADC (ADS1220) sampling those INA333 outputs at 1000 SPS.
Here is the design and signal flow of the circuit for the result I have uploaded in attachments:
my circuit operates at 3.3V from a laboratory dedicated power supply.
1. I have used OPA333 to set the reference of INA333 at the mid supply of 1.65 V(since I am using a potentiometer to set voltage divider to set mid supply for OPA333 input there is some shift I belive in mid supply due to human hand error)
2. 3 INA333 inputs at grounded since my strain gauge is not yet ready to have experimented hence the voltage difference between inputs should be zero(theoretically).
3. I get the ADC input from ina333 outputs and the reference of ADC is power supply reference that is 3.3 V hence ratiometric measurements.
4. Now I have separated the power supply of ANALOG and DIGITAL part of ADC in order to separate noise to a certain degree but still, I am getting noise of 0.7 amplitude at mid supply
I have not got my hands on LP5907 component yet but I have i have included it in the cirucuit( please consider that the plot I got was from two seperate power supply in laboratory which will be replace with LP5907 once I get them)
And Yes I am right now using breadboard to prototype my circuit hence capacitance can be of significane?
Here is attached image of result of above mentioned circuit conditions and schematics.
It would be great if I could remove noise in order to use full 24bit(20bit ) of ADC resolution, thank you.