SMI-BASE-EVAL-KIT1 Silicon Microstructures

Evaluation Kit Manual Contents 1 Quickstart ..................................................................................................................................4 2 Introduction ...............................................................................................................................6 2.1 Sensor Types ................................................................................................................................. 6 2.1.1 Uncompensated - constant voltage operation ..................................................................... 6 2.1.2 Uncompensated - constant current operation ..................................................................... 7 2.1.3 Signal-conditioned - Digital/I2C ............................................................................................ 7 2.1.4 Signal-conditioned - Amplified analog .................................................................................. 7 3 Calibration .................................................................................................................................7 3.1 Why do we need a calibration .................................................................................................... 7 3.2 Theory of Calibration .................................................................................................................. 10 3.2.1 Compensation approaches for uncompensated pressure sensors .................................... 10 3.2.2 Constant voltage mode ....................................................................................................... 11 3.2.3 Constant current mode ....................................................................................................... 16 4 Using the Evaluation Kit ............................................................................................................ 19 4.1 Setup ........................................................................................................................................... 19 4.1.1 Range setup of compensated sensors ................................................................................ 22 4.2 Measurement pages ................................................................................................................... 23 4.3 How to do a calibration ............................................................................................................... 25 4.3.1 Constant voltage calibration ............................................................................................... 26 4.3.2 Constant current calibration ............................................................................................... 29 4.4 Troubleshooting .......................................................................................................................... 30 5 Evaluation Kit Hardware ........................................................................................................... 31 5.1 Hardware Design Explained ........................................................................................................ 31 5.2 Circuitry ....................................................................................................................................... 32 5.2.1 Amplification Circuit ............................................................................................................ 32 5.2.2 Optional Level Shift ............................................................................................................. 33 5.2.3 Power Supply ...................................................................................................................... 34 5.2.4 Temperature Measurement ............................................................................................... 34 5.3 Uncompensated constant current sensor board ........................................................................ 35 6 Expected Performance .............................................................................................................. 36 7 Appendix .................................................................................................................................. 39