SM4291/ SM4391 / SM4491 analog-digital pressure sensor by AMSYS

SM4291 / SM4391 / SM4491 analog-digital pressure sensor

SM4291 / SM4391 / SM4491

The SOIC pressure sensors in the SM4X91 series are analog/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 SM4291/SM4391/SM4491 sensors are supplied in a standard SOIC16 package with two vertical pressure connectors for SMD assembly. Pressure-proportional information in I2C format or as an analog 0.6–5.4-V voltage signal acts as an output signal. SM4291/SM4391/SM4491 are autonomous sensors which do not require any additional circuitry.

SM4291/SM4391/SM4491 are suitable for reflow soldering and automatic assembly on a PCB.

The sensor is available in a relative SM4291 or differential SM4391 sensor version or as asymmetrical, bidirectional, differential pressure sensor SM4491.

Variants of SM4291 / SM4391 / SM4491

SM4291 relative pressure ranges:
0 – 2.5 / 14.9 psi

SM4391 differential pressure ranges:
P1: -14.9 –  -2.5 and P2: 2.5 – 14.9 psi (the absolute values of P1 and P2 must be identical. Please see the datasheet.)

SM4491 bidirectional, asymmetrical 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

AMSYS provides the SOIC sensors in the SM4X91 series as standard versions. The following specifications thereof can be customized, however.


  • Relative, differential and asymmetrical, bidirectional pressure: ±14.9 psi
  • Temperature range: -40–105°C
  • Supply voltage: 3.3 V/5 V
  • Calibrated digital output signal in I²C format
  • Calibrated analog voltage signal
  • Resolution of 16 bits
  • Accuracy: ±1% FS digital, ±1.5% analog
  • Digital ASIC signal processor
  • 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