BMA250 Bosch Sensortec, BMA250 Datasheet - Page 47

• 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

Register (0x28) contains the threshold definition for the slope interrupt. An LSB of (0x28)
slope_th corresponds to an LSB of acceleration data. Its meaning therefore depends on the
selected g-range. Default value of (0x28) slope_th is 0x14.
Register (0x29) is reserved.
Register (0x2A) contains the timing definitions for the single tap and double tap interrupts.
(0x2A) tap_quiet = ´0´ (´1´) selects a quiet duration of 30 ms (20 ms). The default value of
(0x2A) tap_quiet is ´0´.
(0x2A) tap_shock = ´0´ (´1´) selects a shock duration of 50 ms (75 ms). The default value of
(0x2A) tap_shock is ´0´.
(0x2A) tap_dur selects the length of the time window for the second shock event (for double tap
detection). The settings for (0x2A) tap_dur are ´000b´ (50 ms), ´001b´ (100 ms), ´010b´ (150
ms), ´011b´ (200 ms), ´100b´ (250 ms), ´101b´ (375 ms), ´110b´ (500 ms), ´111b´ (700 ms). The
default value of (0x2A) tap_dur is ´100b´.
Register (0x2B) contains the definition of the number of samples to be processed after wake-
up in low-power mode and the threshold definition for the single and double tap interrupts.
(0x2B) tap_samp selects the number of samples that are processed after wake-up in the low-
power mode. The settings for (0x2B) tap_samp are ´00b´ (2 samples), ´01b´ (4 samples), ´10b´
(8 samples), and ´11b´ (16 samples). Default value of (0x2B) tap_samp is ´00b´.
The meaning of an LSB of (0x2B) tap_th depends on the selected g-range. It corresponds to an
acceleration difference of 62.5mg in 2g-range, 125mg in 4g-range, 250mg in 8g-range, and
500mg in 16g-range. Default value of (0x2B) tap_th is 0x0A.
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 53: Samples number definition for the slope interrupt, register (0x28)
Table 54: Tap Quiet duration and tap shock duration, register (0x2A)
Table 55: Samples number after wake-up and threshold tap interrupt, register (0x2B)
Bit 7
samp<1>
slope_
th<7>
Bit 7
Bit 7
quiet
tap_
tap_
Bit 6
samp<0>
slope_
th<6>
shock
Bit 6
Bit 6
tap_
tap_
Bit 5
reserved
reserved
slope_
th<5>
Bit 5
Bit 5
Page 47 / not for publishing
Bit 4
reserved
slope_
th<4>
th<4>
Bit 4
Bit 4
tap_
Data sheet
BMA250
Bit 3
reserved
slope_
th<3>
th<3>
Bit 3
Bit 3
tap_
Bit 2
dur<2>
slope_
th<2>
th<2>
Bit 2
Bit 2
tap_
tap_
Bit 1
dur<1>
slope_
th<1>
th<1>
Bit 1
Bit 1
tap_
tap_
Bosch Sensortec
03 March 2011
Bit 0
dur<0>
slope_
th<0>
th<0>
Bit 0
Bit 0
tap_
tap_