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MPX5999D传感器的应用问题

"Hello, I would like to ask about some issues with the MPX5999D product.

1. Is the reference pressure P2 read in real time, or is it only read once at power‑up?

2. When the pressure at the reference port P2 is below atmospheric pressure, can the sensor operate normally?

3. When the internal circuitry of the sensor performs calibration, is atmospheric pressure used as the calibration condition?"

Re: MPX5999D传感器的应用问题

When this sensor is used for the electronic pressure controller, when P2 = 100 kPa, the electronic pressure controller works normally; when P2 decreases from 100 kPa to 80 kPa, the output flow rate of the electronic pressure controller approaches zero, far lower than the set value. We suspect that the lower reference pressure is causing the sensor to malfunction.

Re: MPX5999D传感器的应用问题

Hi Yuwei,

Please see below my answers to your questions.

1. The sensor measures differential pressure (P1 − P2) applied to both sides of the diaphragm continuously, so the reference pressure at P2 is not sampled only at power‑up but affects the output in real time.

2. Yes, the device can operate with P2 below atmospheric pressure, provided that P1 ≥ P2 and the specified pressure limits are respected.

3. No, the internal circuitry does not use atmospheric pressure as a baseline calibration condition. The sensor's internal calibration is a factory process, not an autonomous runtime routine.

BRs, Tomas

PS: STMicroelectronics has already finalized its acquisition of NXP's MEMS sensor business. All production, support and documentation for these sensors have fully transferred to ST.