SDI 1525 HIGH-END INERTIAL & INDUSTRIAL SURFACE MOUNT ACCELEROMETERS Description：

Datasheet

The Model 1525 MEMS DC surface mount inertial accelerometer incorporates Silicon Designs’ own high-performance sense element, along with a ±4.0V differential analog output stage, internal temperature sensor and integral sense amplifier, all within a miniature, nitrogen damped, hermetically sealed, surface mounted J-lead LCC-20 ceramic package. An average bias repeatability specification of 5 mg for the Model 1525 means that it was designed to provide the high level, long-term stability required for intensive inertial applications within -40 to +85°C environments, such as backup systems for light-to-medium weight aircraft and helicopters. The Model 1525 also features low-power operation, excellent in-run bias stability, and zero cross-coupling, yet remains relatively insensitive to temperature changes and gradients.

Each device is individually tested, programmed, calibrated by SDI, as well as marked with a serial number on its top and bottom surfaces for traceability. A calibration test report (1525-TST) is provided with every unit showing the measured bias, scale factor, linearity, operating current, & frequency response.

ZERO TO MEDIUM FREQUENCY APPLICATIONS

OPERATION

The model 1525 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 Model 1525 produces a differential +/-4 volts output voltage, the value of which varies with acceleration as shown in figure 1. The seismic center is located on a centerline through the dual sense elements halfway between them. Any errors due to rotation about this point are effectively cancelled by the internal electronics.

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 nominally the same as the +2.5 volt input.

PERFORMANCE - ALL VERSIONS

Unless otherwise specified VDD=VR=5.0 VDC, TC=25°C, Differential Output, J-lead package

All Models: Unless otherwise specified, Vs=+8 to +32 VDC, TC=25°C, Differential Mode.

Output Span = ±4V differential output = 8000 mV

Scale = measured value; FS = Full Scale = absolute output = 4000 mV

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