SDI 1521 SURFACE MOUNT ACCELEROMETERS Description：

Datasheet

Silicon Designs Model 1521 Industrial-Grade Surface Mount MEMS DC Accelerometers are rugged and accurate sensors suitable for a wide array of demanding applications. Available in ranges from ±2g to ±400g, and in both leadless LCC and J-Lead packages, the Model 1521 excels in zero-to-medium frequency commercial and industrial applications, and particularly where reliable performance, extremely low noise, and long-term stability are absolute requirements.

SDI's miniature, hermetically sealed package features a MEMS capacitive sense element for DC measurement, paired with a custom integrated circuit incorporating a sense amplifier and differential output stage. This design ensures that the device remains relatively insensitive to temperature changes and gradients. Each package undergoes individual testing, programming, and calibration by SDI, and is marked with a serial number on its top and bottom surfaces for easy traceability. Additionally, an optional calibration test report (1521-TST) is available for every unit, displaying the accelerometer's measured bias, scale factor, linearity, operating current, and frequency response specifications.

ZERO TO MEDIUM FREQUENCY APPLICATIONS

OPERATION

The Model 1521 produces a differential +/-4 volts output voltage or single ended mode, 0.5 – 4.5 volts full scale, the value of which varies with acceleration as shown in the figures below. The sensitive axis is perpendicular to the bottom of the package, with positive acceleration resulting from a positive force pushing on the bottom of the package. The seismic center is located on a centerline through the dual sense elements and halfway between them. The internal electronics effectively cancel any errors due to rotation.

Two reference voltages, +5.0 and +2.5 volts (nominal), are required; scale factor is ratiometric to the +5.0 volt reference voltage relative to GND, and both outputs at zero acceleration are the same as the +2.5 volt input.

PERFORMANCE - ALL VERSIONS

All Models: Unless otherwise specified, Vs=+8 to +32 VDC, TC=25°C, Differential Mode. Span = ±g range = 8000 mV.

Note (1): For 2g thru 50g only; 100g and greater versions are tested and specified from -65 to +65g.

NOTICE: Stresses greater than those listed may cause permanent damage to the device. These are maximum stress ratings only. Functional operation of the device at or above these conditions is not implied.

PACKAGE DIMENSIONS