BMA250 Bosch Sensortec, BMA250 Datasheet - Page 50

• 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

5.14 Interface configuration
Register (0x34) contains the settings for the digital interfaces. Writing ´1´to (0x34) i2c_wdt_en
enables the watchdog at the SDI pin (= SDA for I²C) if I²C is selected. Default value of (0x34)
i2c_wdt_en is ´0´.
(0x34) i2c_wdt_sel selects the I²C data pad watchdog timer period. The settings for (0x34)
i2c_wdt_sel are ´0´ (1 ms) and ´1´ (50 ms). Default value of (0x34) i2c_wdt_sel is ´0´.
(0x34) spi3 selects the SPI mode. The settings for (0x34) spi3 are ´0´ (4-wire SPI) and ´1´ (3-
wire SPI). Default value of (0x34) spi3 is ´0´.
Register (0x35) is reserved.
5.15 Offset compensation
Register (0x36) contains settings for the offset compensation in general, for fast offset
compensation, and for slow offset compensation. Writing ´1´to (0x36) offset_reset sets all offset
compensation registers (0x38 to 0x3D) to zero.
Default value of (0x36) offset_reset is ´0´.
(0x36) cal_trigger starts the fast compensation process for the specified axis. The settings for
(0x36) cal_trigger are ´00b´ (no axis selected), ´01b´ (x-axis), ´10b´ (y-axis), ´11b´ (z-axis). A
non-zero value is kept until the fast compensation procedure is finished. Default value of (0x36)
cal_trigger is ´00b´.
(0x36) cal_rdy indicates the state of the fast compensation. (0x36) cal_rdy is ´0´ when (0x36)
cal_trigger has a nonzero value, otherwise (0x36) cal_rdy is ´1´.
Writing ´1´ (´0´) to (0x36) hp_z_en enables (disables) slow offset compensation for the z-axis.
Writing ´1´ (´0´) to (0x36) hp_y_en enables (disables) slow offset compensation for the y-axis.
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.
Table 61: EEPROM control settings, register (0x33)
Table 62: EEPROM control settings, register (0x34)
reserved
reserved
Bit 7
Bit 7
reserved
reserved
Bit 6
Bit 6
reserved
reserved
Bit 5
Bit 5
Page 50 / not for publishing
reserved
reserved
Bit 4
Bit 4
Data sheet
BMA250
reserved
nvm_loa
Bit 3
Bit 3
d
nvm_rdy
i2c_wdt
Bit 2
Bit 2
_en
nvm_pro
i2c_wdt
Bit 1
Bit 1
_sel
_trig
g
Bosch Sensortec
03 March 2011
nvm_pro
_mode
Bit 0
spi3
Bit 0
g