Hey,
I've got a project that is using one piezo transducer/sensor to both drive a vibration in a resonator and to generate a signal from the resulting vibration, which would be later amplified by an op-amp. To drive the piezo I decided to go with TI's DRV2700. It has a boost circuit that will give me a +-105V output that the piezo needs. Once the piezo has been vibrating for some number milliseconds I will shut the DRV2700 drive signal off and receive the ringing signal from the piezo and amplify it using an op-amp. The obvious issue is that I cannot simply have the op-amp input pins directly connected to the piezo since it will be driven at 105V. The good thing is the 105V signal will take place at a different time (previous) to when I want to amplify the resulting signal with the op-amp (post).
Btw I should say that I'm trying to accomplish this without adding a second piezo to receive the signal.
I searched mouser/digikey and found analog switches that can handle up to 200V but they are too expensive. I am looking for a more clever solution. For example, I do not need the 105V signal running through the switch. I could simply put the op-amp inputs through the switch. But as I am searching, I'm not sure if there is a difference between being exposed to (but not conducting) 105V. Some analog switches like DG2733e explicitly say the pins cannot block voltage much above the 5V supply.
Are there analog switches I am missing or possibly another solution you guys can see for this?
I've got a project that is using one piezo transducer/sensor to both drive a vibration in a resonator and to generate a signal from the resulting vibration, which would be later amplified by an op-amp. To drive the piezo I decided to go with TI's DRV2700. It has a boost circuit that will give me a +-105V output that the piezo needs. Once the piezo has been vibrating for some number milliseconds I will shut the DRV2700 drive signal off and receive the ringing signal from the piezo and amplify it using an op-amp. The obvious issue is that I cannot simply have the op-amp input pins directly connected to the piezo since it will be driven at 105V. The good thing is the 105V signal will take place at a different time (previous) to when I want to amplify the resulting signal with the op-amp (post).
Btw I should say that I'm trying to accomplish this without adding a second piezo to receive the signal.
I searched mouser/digikey and found analog switches that can handle up to 200V but they are too expensive. I am looking for a more clever solution. For example, I do not need the 105V signal running through the switch. I could simply put the op-amp inputs through the switch. But as I am searching, I'm not sure if there is a difference between being exposed to (but not conducting) 105V. Some analog switches like DG2733e explicitly say the pins cannot block voltage much above the 5V supply.
Are there analog switches I am missing or possibly another solution you guys can see for this?