BMA020 Bosch Sensortec, BMA020 Datasheet - Page 10

• Manufacturer Part Number: BMA020
• Description: 3-AXIS ACCELEROMETER DIGITAL I/F
• Manufacturer: Bosch Sensortec

Specifications of BMA020

• Axis: X, Y, Z
• Acceleration Range: ± 2g, 4g, 8g
• Sensitivity: 256LSB/g, 128LSB/g, 64LSB/g
• Voltage - Supply: 2 V ~ 3.6 V
• Output Type: Digital
• Bandwidth: 3kHz
• Interface: I²C, SPI
• Mounting Type: Surface Mount
• Package / Case: 12-LGA
• For Use With: 828-1014 - BMA020 TRIBOX DEMO BOARD W/USB828-1008 - BMA020 DAUGHTERCARD FOR DEV KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 828-1000-2

3.1 Operational registers
3.1.1 SPI4
The SPI4 bit ((address 15h, bit 7) is used to select the correct SPI protocol (three-wire or four-
wire, SPI-mode 3). The default value is SPI4=1 (four-wire SPI is default value). After power on
reset or soft reset it is recommended to set the SPI4-bit to the correct value.
This first writing is possible because only CSB, SCK and SDI are required for a write sequence
and the 3 bit timing diagrams are identical in three-wire and four-wire configuration.
Recommended procedure: Set SPI4 to the correct value (SPI4=0 for SPI three-wire, SPI4=1 for
SPI four-wire (=default)) every time after power on reset or soft reset.
3.1.2 Range
These two bits (address 14h, bits 4 and 3) are used to select the full scale acceleration range.
Directly after changing the full scale range it takes 1/(2*bandwidth) to overwrite the data
registers with filtered data according to the selected bandwidth.
Table 3: Settings of full scale range register
Important note:
Please refer to the comment in chapter 3 of how to protect bits 5, 6 and 7 when modifying other
bits of register 14h.
Rev. 1.2
© 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.
range<1:0>
00
01
10
11
Digital, triaxial acceleration sensor
Full scale acceleration range
Data sheet
BMA020
Page 10
Not authorised code
+/- 2g
+/- 4g
+/- 8g
Bosch Sensortec
30 May 2008