Mechanical and electrical specifications

LIS302ALK

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over lifetime. The Zero-g level tolerance describes the range of Zero-g levels of a population

of sensors.

Self Test allows to check the sensor functionality without moving it. The Self Test function is

off when the ST pin is connected to GND. When the ST pin is tied at Vdd an actuation force

is applied to the sensor, simulating a definite input acceleration. In this case the sensor

outputs will exhibit a voltage change in their DC levels which is related to the selected full

scale and depending on the Supply Voltage through the device sensitivity. When ST is

activated, the device output level is given by the algebraic sum of the signals produced by

the acceleration acting on the sensor and by the electrostatic test-force. If the output signals

change within the amplitude specified inside Table 2, than the sensor is working properly

and the parameters of the interface chip are within the defined specification.

Output impedance describes the resistor inside the output stage of each channel. This

resistor is part of a filter consisting of an external capacitor of at least 2.5nF and the internal

resistor. Due to the resistor level, only small inexpensive external capacitors are needed to

generate low corner frequencies. When interfacing with an ADC it is important to use high

input impedance input circuitries to avoid measurement errors. Note that the minimum load

capacitance forms a corner frequency close to the resonance frequency of the sensor. In

general the smallest possible bandwidth for a particular application should be chosen to get

the best results.