INA333: Use for wheatstone bridge strain sensor

vivek plawat said:

Part Number: INA333

We are developing a wearable device where we need two independent wheatstone bridge strain gauge circuits - one to measure skin resistance (average 0.5K ohms resistance) and other to have a strain gauge sensor (120 ohms). We need a low power with programmable gain. We were looking at OPA2333 / LPV812 / INA333

Can we use two channel amplifier to use two independent strain gauges with Vref?

Which are the best suited amplifiers and respective Vref chips?

Or shall I use INA333 and a multiplexer like TS3a24159 to use both the strain gauges with the same amplifier?

Hi Vivek,

Thank you for your post. I can help you.

It would be helpful to know a bit more about your application. For each bridge (500ohm and 120ohm), can you answer the following?:

• What is the excitation voltage?
• What is the expected input differential voltage range?
• How much gain do you need?
• What is the expected output voltage of the INA or OPA?
• What supplies are available?
• Do you need to measure both sensors simultaneously?

INA333 is a great choice for bridge sensor amplification owing to its high precision and low power operation.

-Tamara