Bosch MAN-REG-X-08 Especificaciones descargar pdf (Pagina 37)

Data sheet

BMA220

Page 37

BST-BMA220-DS003-08 | Revision 1.15 | August 2011 Bosch Sensortec

third parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.

Note: Specifications within this document are subject to change without notice.

6.5 Self test mode

The sensor features an on-chip self-test mode. The self test is realized by a physical deflection

of the seismic mass due to an applied electrostatic force. Thus, it provides full testing of the

complete signal evaluation path including the micromachined sensor structure and the

evaluation ASIC.

The self test mode can be activated individually for each axis by setting the the sbist register to

the corresponding value (

‘01’=x-axis, ‘10’=y-axis, ‘11’=z-axis). The self test works in all

acceleration ranges. By setting the sbist_sign register to

‘1’, the polarity of the self test signal

can be changed from positive to negative.

The self test response remains as a static offset on the output as long as the sbist register is not

set back to

‘00’. While the self test is activated, any acceleration or gravitational force applied to

the sensor will be observed in the output signal as a superposition of both acceleration and self

test signal.

self test response

output signal [LSB]

sbist register

sbist_sign register

Figure 13: Self-test mode

1 2 ... 32 33 34 35 36 37 38 39 40 41 42 ... 62 63

Sin comentarios

Bosch MAN-REG-X-08 Especificaciones Pagina 37