MPX2100 AC voltage excitation

[CCDaniel]

For a special low-voltage application I would like to use an AC excitation voltage instead of DC for a silicon pressure sensor of the MPX2100 family.

As they are passive devices I see no impediment. I also measured the sensor bridge with an ohm-meter, no difference in either voltage polarity, direction.

Does this also hold with excitation voltages of +-2Vpp ?

The measured pressure output voltage will be an AC voltage too, which is my intention in this application, to get rid of any amplifier offset voltage problems, low frequency noise and use pure AC-coupling.

Sincerely

[diazmarin09 · Accepted solution]

Hello Daniel,

I hope all is great with you. Thank you for using the NXP communities.

Please note that it is recommended to supply the device with Vdc.

This is not a passive device. Internally, it features a Temperature Compensation and Calibration Circuitry. So I do not recommend supplying the device with Vac.

I hope this information helps.

Regards,

David

[CCDaniel]

Hello David,

many thanks for a clear and simple advise/explanation. So my simple measurements with an ohm-meter deceived me. The internal compensation circuitry may contain diodes, not just semiconductor resistances. I saw another barometer design which uses a low 1.5V 1 Hz pulsed excitation voltage for low current consumption in the bridge circuit.

So positive pulsed may be ok and must fulfill my ideas...

sincerely, Christian