BMA250 SHUTL Bosch Sensortec, BMA250 SHUTL Datasheet - Page 19

• Manufacturer Part Number: BMA250 SHUTL
• Description: BMA250 DAUGHTERCARD FOR DEV KIT
• Manufacturer: Bosch Sensortec
• Series: -r

Specifications of BMA250 SHUTL

• Featured Product: BMA250 - Digital, Triaxial Acceleration Sensor
• Sensor Type: Accelerometer, 3 Axis
• Sensing Range: ±2g, 4g, 8g, 16g
• Interface: -
• Sensitivity: 256LSB/g, 128LSB/g, 64LSB/g, 16LSB/g
• Voltage - Supply: -
• Embedded: No
• Utilized Ic / Part: BMA250
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 828-1024

The meaning of both public and internal registers is the same for all acceleration measurement
ranges. Therefore, with measurement ranges other than ±2g, one or more lower significant bits
of the internal registers are lost when added to an acceleration value, or are set to zero when
the internal compensation value is computed. If a compensation value is too small or too big to
fit into the corresponding internal register, it is saturated to prevent an overflow error.
In a similar way the conversion of the internal register value to the public register value (10bit to
8bit) uses saturation.
Summarized, in dependence to the measurement range which has been set, the compensation
value, which has been written into the public register will correct the data output according to
figure 4.
e.g. ±2g range:
public register = 00000001b  add to acceleration data = ±7.8mg
public register = 00000010b  add to acceleration data = +15.6mg
public register = 00000101b  add to acceleration data = +39.1mg
The public registers are image registers of EEPROM registers. With each image update (see
section 4.7 Non-volatile memory for details) the contents of the non-volatile EEPROM registers
are written to the public registers. At any time the public register can be over-written by the user.
After changing the contents of the public registers by either an image update or manually, all
8bit values are widened to 10bit values and stored in the corresponding internal registers. In the
opposite direction, if the value of an internal register changes due to the computation performed
by a compensation algorithm, it is converted to an 8bit value and stored in the public register.
Rev. 1.0
© Bosch Sensortec GmbH reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to 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.
Figure 4: Principle of offset compensation
Page 19 / not for publishing
Data sheet
BMA250
= +2LSB
= +4LSB
= +10LSB
Bosch Sensortec
03 March 2011