BMA250 Bosch Sensortec, BMA250 Datasheet - Page 55

• 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

6.1 Serial peripheral interface (SPI)
The timing specification for SPI of the BMA250 is given in the following table:
Table 73: SPI timing
The following figure shows the definition of the SPI timings given in table 73:
The SPI interface of the BMA250 is compatible with two modes, ´00´ and ´11´. The automatic
selection between [CPOL = ´0´ and CPHA = ´0´] and [CPOL = ´1´ and CPHA = ´1´] is done
based on the value of SCK after a falling edge of CSB.
Two configurations of the SPI interface are supported by the BMA250: 4-wire and 3-wire. The
same protocol is used by both configurations. The device operates in 4-wire configuration by
default. It can be switched to 3-wire configuration by writing ´1´ to (0x34) spi3. Pin SDI is used
as the common data pin in 3-wire configuration.
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.
Parameter
Clock Frequency
SCK Low Pulse
SCK High Pulse
SDI Setup Time
SDI Hold Time
SDO Output Delay
CSB Setup Time
CSB Hold Time
Symbol
f
t
t
t
t
t
t
t
SPI
SCKL
SCKH
SDI_setup
SDI_hold
SDO_OD
CSB_setup
CSB_hold
Figure 10: SPI timing diagram
Page 55 / not for publishing
Condition
Max. Load on SDI or
SDO = 25pF
Load = 25pF
Load = 250pF,
V
DDIO
= 2.4V
Data sheet
BMA250
Min
20
20
20
20
20
40
Max
10
30
40
Units
MHz
ns
ns
ns
ns
ns
ns
ns
ns
Bosch Sensortec
03 March 2011