Product Features

The PSØ21 is a digital front-end device for measuring strain gages. Using PICOSTRAIN measurement principle the PSØ21 provides a high degree of flexibility. The current consumption of the total system, including the sensor, can be reduced down to less than 100 μA. The precision that can be achieved is better than most 24-bit A/D-converters and even surpasses them at high measurement rates. The PSØ21 is capable of measuring 2 Wheatstone bridges, 2 full or 4 half-bridges. Driving one half bridge is also possible without any loss in precision. An additional port for temperature measurement, patented compensation methods and a serial SPI interface makes the PSØ21 an innovative front end for various strain gage applications.

Part Descriptions

Features

• Up to 4 half bridges, 2 full bridges, or 2 Wheatstone bridges
• Programmable resolution up to 19 bits rms
• Measuring rate up to 50 kHz
• Extremly low current consumption (down to 15 μA incl. the strain gage)
• Wide offset range, +/- 250 mV/V
• Separate temperature measurement port
• Resistance strain gages: 350 Ohm to 10 kOhm
• High temperature stability and low gain error (1ppm / K)
• SPI interface with separate supply voltage
• Core voltage 1.8 V to 3.6 V, I/O voltage 1.8 V to 5.5 V
• Temperature range –40°C to +120°C
• TQFP48 / QFN48 package, 7 x 7 mm2 body

Applications

• Telemetric applications
• Force sensors/load cells
• Pressure sensors (also 4 – 20 mA)