BMA250 Bosch Sensortec, BMA250 Datasheet - Page 11

• Manufacturer Part Number: BMA250
• Description: 3-AXIS ACCELEROMETER DIGITAL I/F
• Manufacturer: Bosch Sensortec
• Series: -r

Specifications of BMA250

• Featured Product: BMA250 - Digital, Triaxial Acceleration Sensor
• Axis: X, Y, Z
• Acceleration Range: ±2g, 4g, 8g, 16g
• Sensitivity: 256LSB/g, 128LSB/g, 64LSB/g, 16LSB/g
• Voltage - Supply: 1.62 V ~ 3.6 V
• Output Type: I²C™, SPI™
• Bandwidth: 8Hz ~ 1kHz
• Interface: I²C, SPI
• Mounting Type: Surface Mount
• Package / Case: 12-VQFN
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With: 828-1024 - BMA250 DAUGHTERCARD FOR DEV KIT
• Other names: 828-1023-2

both supply voltages. In case the I²C interface shall be used, a direct electrical connection
between V
(see section 4.2 Operational modes).
4.2 Operational modes
Depending on the configuration the BMA250 is able to operate in two different operational
modes:
The selection of the operational mode is done during start-up or reset by the state of the PS pin.
If PS is floating, the dedicated mode is selected. A defined digital state selects the general
mode. All pads are in input mode (no output driver active) during the start-up sequence until the
operational mode and, in case of the general mode, the interface type is selected. The start-up
sequence is run after power-up and after reset.
Figure 2 illustrates the selection of the different operational modes:
Rev. 1.0
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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.


General mode: The device is acting as a slave on a digital interface (SPI or I²C) and is
controlled by the external bus master (e.g. μC). The master gets measurement data and
status information from the device through the digital interface. In particular, the master
can configure the interrupt controller and read out the interrupt status registers.
Moreover, it can freely configure and use the two interrupt pins (INT1, INT2). Several
interrupts may be enabled in parallel.
Dedicated mode: The dedicated mode allows the sensor to be operated as a stand-
alone device in a simple μC-less system without abandon of the interrupt functionality.
No digital interface is needed and, as a consequence, no measurement data can be
read from the device. Instead of the digital interface the internal interrupt engine with its
default setting is used. The interrupt status is mapped onto dedicated output pins. One
out of three different sub-modes can be chosen: A) orientation recognition, B) tap
sensing or C) slope (any-motion) detection. Only one interrupt at a time can be
assigned.
DDIO
supply and the PS pin is needed in order to ensure reliable protocol selection
Figure 2: Operational mode selection
Page 11 / not for publishing
Data sheet
BMA250
Bosch Sensortec
03 March 2011