BMC150 datasheet(24/142 Pages) BOSCH

24 / 142 page

Datasheet

eCompass BMC150

Page 24

BST-BMC150-DS000-04 | Revision 1.0 | July 2014

Bosch Sensortec

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. Not intended for publication.

data acquisitions). Hence, the more repetitions are acquired to generate one magnetic field data

point, the longer the active time ratio in one sample phase, and the higher the average current.

Thanks to longer internal averaging, the noise level of the output data reduces with increasing

number of repetitions.

By using forced mode, it is possible to trigger new measurements at any rate. The user can

therefore trigger measurements in a shorter interval than it takes for a measurement cycle to

complete. If a measurement cycle is not allowed to complete, the resulting data will not be

written into the data registers. To prevent this, the manually triggered measurement intervals

must not be shorter than the active measurement time which is a function of the selected

number of repetitions. The maximum selectable read-out frequency in forced mode can be

calculated as follows:

µs

nXY

µs

ODR

980

500

145

max,











Hereby nXY is the number of repetitions on X/Y-axis (not the register value) and nZ the number

of repetitions on Z-axis (not the register value) (see description of XY_REP and Z_REP

registers in chapter 7).

Although the repetition numbers for X/Y and Z axis and the ODR can be adjusted independently

and in a wide range, there are four recommended presets (High accuracy preset, Enhanced

regular preset, Regular preset, Low power preset) which reflect the most common usage

scenarios, i.e. required output accuracy at a given current consumption, of the BMC150

magnetometer part.

The four presets consist of the below register configurations, which are automatically set by the

BMC150 API or driver provided by Bosch Sensortec when a preset is selected. Table 6 shows

the recommended presets and the resulting magnetic field output noise and magnetometer part

current consumption:

Table 6: Magnetometer presets in Active operation and normal mode:

Preset

X/Y rep

Z rep

ODR

ODRmax

(forced

mode)

RMS Noise

x/y/z

Average

current

consumption

Low

power

preset

10 Hz

>300 Hz

1.0/1.0/1.4 µT

170 µA

Regular

preset

10 Hz

100 Hz

0.6/0.6/0.6 µT

0.5 mA

Enhanced

regular preset

10 Hz

60 Hz

0.5/0.5/0.5 µT

0.8 mA

High accuracy

preset

20 Hz

0.3/0.3/0.3 µT

4.9 mA

BMC150 Datasheet(PDF) 24 Page - Bosch Sensortec GmbH

BMC150 Datasheet(HTML) 24 Page - Bosch Sensortec GmbH

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL