SM4221 / SM4321 / SM4421 digital pressure sensor by AMSYS

SM4221 / SM4321  / SM4421 digital pressure sensor

SM4221 / SM4321 / SM4421

The SOIC pressure sensors in the SM4X21 series are digital OEM sensors with a new silicon sensing element and modern electronic signal conditioning unit. The integrated digital signal processor permits calibration and temperature compensation during production.

The fully calibrated SM4221, SM4321 and SM4421 sensors are supplied in a standard SOIC16 package with two vertical or horizontal pressure connectors for SMD assembly. Pressure-proportional information in I2C format acts as an output signal. SM4221/SM4321/SM4421 are autonomous sensors which do not require any additional circuitry.

SM4221/SM4321/SM4421 are suitable for reflow soldering and automatic assembly on a PCB.

The sensor is available in a relative SM4221 or differential SM4321 sensor version or as asymmetrical, bidirectional, differential pressure sensor SM4421.

Variants of SM4221/SM4321/SM4421

SM4221 relative pressure ranges: 0 – 2.5 / 14.9 psi

SM4321 differential pressure ranges:
P1: -14.9 – -2.5 psi and P2: 2.5 – 14.9 psi (the absolute values of P1 and P2 must be identical. Please see the datasheet.)

SM4421 asymmetrical bidirectional pressure ranges:
P1: -14.9 – 0 and P2: 0 – 14.9 psi (the absolute values of P1 and P2 may differ from one another. The difference between P1 and P2 must be greater than 2 psi, however. Please see the datasheet.)

Link to the pressure converter

The SOIC sensors in the SM4X21 series are supplied by AMSYS as standard products and the following specifications thereof can be customized.


  • Relative, differential and asymmetrical, bidirectional pressure: ±14.79 psi
  • Compensated temperature range: -40–105°C
  • Supply voltage: 3.3 V/5 V
  • Calibrated digital output signal
  • I²C format
  • Resolution of 14 bits
  • Accuracy: 1% FS
  • Digital ASIC signal processor
  • Bidirectional and differential versions
  • SOIC16 package for SMD assembly
  • ISO & ISO/TS certified
  • RoHS and REACH compliant


  • HVAC
  • Fan control
  • Gas flows
  • Airstream measurement

For information on prices and delivery times or if you have any technical questions, please contact