SMD288

The Bosch SMD288 is an absolute pressure sensor designed for measuring atmospheric pressure, primarily used in electronic control units for automotive applications such as diesel or gasoline engine management. It covers a pressure range of 50 to 115 kPa.

This sensor utilizes a micromechanical silicon diaphragm with four piezo-resistors connected in a Wheatstone bridge. The deflection caused by applied pressure generates an output voltage proportional to the pressure. The integrated electronic circuit on the silicon chip provides signal amplification and temperature compensation. A reference vacuum is maintained on the backside of the diaphragm.

The SMD288 supplies an analog output signal that is ratiometric to the supply voltage. It is assembled in a premold housing with a standard SO footprint, suitable for surface mounting. An external RC low-pass filter with a time constant of approximately 2 ms may be added to reduce supply line ripples.

Key specifications include a pressure range of 50-115 kPa, a typical operating voltage of 5V, and an operating temperature range from -40°C to 125°C. The sensor also has a burst pressure rating of 600 kPa and a current rating of 12mA.