Hello all,

I have a university project consisting in making a force transducer composed of one LVDT and a spring. I'm currently looking for a LVDT signal conditioning circuit to make and I have stumbled upon these two chips (AD598 and AD698)

All I need is a 10V DC output at 17bit resolution so I can convert it to Digital. I also need to know if the core is one the right or the left, I suppose that you can do that by the absolute value of the output coupled by the value of the phase. Correct me if I'm wrong, this all quite new to me.

From what I understand the two chips process the information differently, but the output is exactly the same. So what's the point of making two chips that do things differently to get the same result. Unless the AD598 has different applications compared to the AD698?

TLDR: Basically I need to know how far the core has traveled so I can determine through the spring constant how much force has been applied. So which one is best suited for my case, knowing that I need as much resolution and accuracy as possible (no noise or phase lag or whatever)

Thanks in advance

Samuel

Hi,

You are correct in that the output of both parts, the AD598 and AD698, are the same but the parts are designed to work with different LVDT sensors.

The AD598 is designed to work with a 5-wire LVDT which has a (A-B)/(A+B) transfer function.

The AD698 is designed to work with a 4-wire or 3-wire LVDT which have a A/B transfer function.

So the choice of component, AD598 or AD698 depends on the sensor you are using.

Either part will give a 0 to 10V output but the accuracy is not at the 17-bit level