Digital altimeter spans 10 mBar to 2000 mBar pressure range

November 12, 2013 // By Graham Prophet
The low-power MS5806 is presented as suitable for adventure and multi-mode watch applications.

Measurement Specialties' MS5806 is a compact digital barometric pressure sensor module that operates over an extended pressure range of 10 mBar to 2000 mBar. Altitude resolution of up to 20 cm makes it ideal for use in altimeters and variometers (vertical speed meters). Measuring 6.4 x 4.0 x 2.75 mm, the MS5806 fits in space-constrained devices including high-end thin watches, adventure and multi-mode watches, fitness gadgets, mobile altimeter/barometer systems and bike computers.

The 24-bit ΔΣ ADC integrated digital pressure sensor features several different operation modes to optimise conversion speed and current consumption. The sensor converts the device’s uncompensated analogue output voltage from the piezo-resistive pressure sensor to a 24-bit value, while also providing a 24-bit value for the temperature of the sensor.

The hermetically-sealed MS5806 features a protective cap constructed of an anticorrosive, polished stainless steel and is filled with a silicone gel protecting the sensor and bonding wires. An optional O-ring placed on the cap’s outer diameter provides water-resistance to 100m, while avoiding mechanical stresses on the sensor.

The MS5806 uses six coefficients to compensate for process variations for increased measurement accuracy as well as I²C or SPI communication to offer a conversion time down to 0.6 msec. It can be interfaced to virtually any microcontroller.

Specification points include;

Low current demand of 0.9 μA (standby <0.15 μA at 25°C)

Supply voltage range of 1.8 to 3.6V

Pressure range: 300 mBar to 1100 mBar (Extended: 10 mBar to 2000 mBar)

Operating temperature range of -40°C to +85°C

±2.5 mBar typical pressure accuracy (with auto zero at one pressure point)

Temperature accuracy of ±0.8°C at 25°C

Temperature resolution less than 0.01°C

The MS5806 costs $11.80 (10,000)

Measurement Specialties;