PVC4000 Series MEMS Pirani Vacuum Transducers

The sensing element is based on Posifa’s second generation MEMS thermal conduction chip, which operates on the principle that the thermal conductivity of gases is proportional to vacuum pressure. The electronics and microprocessor amplify and digitize the sensor signal and provide output via an I 2 C interface. Because thermal conductivity varies with ambient temperature, the microprocessor applies a temperature compensation algorithm using input from a built-in temperature sensor.

Output from the PVC4000 Series is uncalibrated; as an option, users can enter up to ten pairs of calibration points via I 2 C, and a built-in piecewise linearization algorithm uses this data to provide calibrated output. To further facilitate integration, devices in the series include a connector-terminated wire harness soldered onto the PCB assembly.

Device Options

The PVC4000 Series is offered in two device options. PVC4001 provides Pirani-based
vacuum measurement over 10⁻³ to 760 Torr in an SMD-sensor configuration. PVC4001-
C is the PVC4001 configuration with an onboard barometric pressure sensor added;
because Pirani vacuum sensors typically lose resolution above 10 Torr, the barometric
sensor supports measurement from 10 Torr to 900 Torr with 2% accuracy across that
extended range.

Absolute Maximum Ratings

• Operating Temperature: -25 to 85 °C
• Storage Temperature: -40 to 90 °C
• Shock: 100 g peak (5 drops, 3 axis) • Overpressure: 27.5 bar