NXP MPXV5050 Vacuum sensor support

maheshvastrad · ‎06-09-2016

We have been working for a AUTOMOTIVE FILTER SENSOR project, based on MPXV5050 (NXP absolute vacuum sensor. We've deveoped our customized board using NXP MCU S9S08 Series. We have matched all the functional points required for reading pressure/ vacuum via MCU ADC & convert it to digital value.

During our testing we set point as 3.276 V corresponding to 405mBar

Since boards were meeting all required o/p parameters in testing conditions without potting in housing/ enclosure,

Later after QC testing as OK, We Potted it with Hard-Epoxy component.

After potting, we found the Reference has shifted by 30mBar.

What could be the reason, Please help us with suggestions/ remedies / precautions to be taken care.

Meanwhile, can you kindly connect me with any NXP PRESSURE/ VACUUM Sensor experts to

Resolve the issue.

maheshvastrad · ‎07-20-2016

Hi David,

Thanks for your support on Vacuum sensors, Meanwhile there are 2 more queries.

1. After inserting the FULLY-MOUNTED PCB in housing ... during field trial with Vehicle sensor P1 side of housing comes in contact with DIESEL...

Kindly let us know what would be the consequence/ effect on MPXV5050 Vacuum sensors.

2. Can we have specific mounting and soldering information on single port, Axial, type of sensor package. The part number is MPXV5050VC6T1. Your App notes, shared earlier, do not talk about this package.

Kindly guide

Regards

Mahesh.V.S.

david_diaz · ‎07-20-2016

Hello Mahesh,

My apologies for the delayed response.

Please note that for all NXP standard pressure sensor products, any environment other than dry air, will have some impact on the reliability and lifetime of the product. NXP's silicon pressure sensors are NOT compatible with oil, gas, petrol and water or water vapors, or chemicals.

A determination must be made if this impact is acceptable for the application. That means that you cannot use our pressure sensors in such applications in which the sensor may be in direct contact with diesel. After some working hours, maybe days the device would fail.

I would like refer to the following application notes that would be worth to be considered in addition to the provided information and solutions:

AN3728 - Media Compatibility for IPS PRT Pressure Sensors

AN1516 - Liquid Level Control Using a Pressure Sensor

AN1950 - Water Level Monitoring

In regard with the soldering and mounting techniques about the axial port, other than the information on the datasheet, we only have the material composition declaration report of this device that you can find on the following link:

MPXV5050VC6T1 - MCD Report

The AN1984 about how to handle NXP Pressure Sensors may be useful for you:

I hope this information will be useful for you.

If I misunderstood your question, feel free to let me know. I will be glad to help.

Have a great day.

David Diaz.

omarpugliesi · ‎05-29-2018

Is there some sensor that may I use directly with water?

maheshvastrad · ‎06-16-2016

Hi David,

Thanks for your response.

Customer would like to have specific mounting and soldering information on single port, Axial, type of sensor package. The part number is MPXV5050VC6T1. Your App notes, shared earlier, do not talk about this package.

Thanks in Advance.

Mahesh.V.S.

rajivbandodkar · ‎06-10-2016

Hi David two more question:

3. Is there a 5 Volt Vacuum sensor with -50 to 0 Kpa range, the current one we are using is 3.3V

4. Do you have any assembly guidelines App note for pressure sensors?

Regards,

Rajiv Bandodkar.

david_diaz · ‎06-13-2016

Hello Rajiv,

The MP3V5050VC6U is a Gauge pressure sensor, which means that, it measures the difference between the absolute pressure and the Local atmospheric pressure.

P2 port is intended to be left open to the atmosphere. I strongly do not recommend covering the small hole.

Have you considered using an Absolute pressure sensor?

The typical voltage supply of almost all our absolute pressure sensors is 5V. Unfortunately, that range of pressure is not available.

In regard with the assembly guidelines, I would like to recommend the following documents that describes several mounting techniques, offers lead forming recommendations, soldering recommendations, and suggests means of testing the MPX series of pressure sensors:

1. Mounting Techniques, lead forming, and testing of the MPX Series pressure sensors

2. Soldering Recommendations for Pressure Sensor Devices

I hope this information will be useful for you.

If I misunderstood your question, feel free to let me know. I will be glad to help.

Have a great day.

David Diaz.

PS: If my answer helps to solve your question, please mark it as "Correct". Thank you.

rajivbandodkar · ‎06-10-2016

Hi David,

1. In our application we have selected MP3V5050VC6U, and the single port is connected to the diesel filter, there will not be the occasion to reference it to atmospheric pressure. So what is the solution.

2. The P2 hole in the sensor: should it be open to atmosphere? if yes, How about contamination with dust, water, etc

Regards,

Rajiv Bandodkar.

david_diaz · ‎06-09-2016

Hello Mahesh,

I assume the pressure on-box after the potting compound is affecting on the pressure sensor because it is pressing down the sensor package affecting its measures and creating this offset.The temperature could be another factor.

In this case, I recommend Implementing Auto-Zero for Integrated Pressure Sensors.

Auto-zero is a compensation technique based on sampling the offset of the sensor at reference pressure (atmospheric pressure is a zero reference for a gauge measurement) in order to correct the sensor output for long-term offset drift or variation.

I hope this information will be useful for you.

If I misunderstood your question, feel free to let me know. I will be glad to help.

Have a great day.

David Diaz.

PS: If my answer helps to solve your question, please mark it as "Correct". Thank you.