HAL815 datasheet(8/24 Pages) MICRONAS

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HAL 815

ADVANCE INFORMATION

Micronas

Note: During application design, it should be taken

into consideration that the maximum and minimum

ADC-READOUT is not exceeded during calibration

and operation of the Hall IC. Consequently, the maxi-

mum and minimum magnetic fields that may occur in

the operational range of a specific application should

not saturate the A/D converter. Please note that the

A/D converter saturates at magnetic fields well above,

respectively below, the magnetic range limits. This

large safety band between specified magnetic range

and true operational range helps to avoid any satura-

tion.

Range

The RANGE bits are the three lowest bits of the MODE

A/D converter.

Filter

The FILTER bits are the three highest bits of the

MODE register; they define the

−3 dB frequency of the

digital low pass filter.

TC and TCSQ

The temperature dependence of the magnetic sensitiv-

ity can be adapted to different magnetic materials in

order to compensate for the change of the magnetic

strength with temperature. The adaption is done by

programming the TC (Temperature Coefficient) and

the TCSQ registers (Quadratic Temperature Coeffi-

cient). Thereby, the slope and the curvature of the tem-

perature dependence of the magnetic sensitivity can

be matched to the magnet and the sensor assembly.

As a result, the output voltage characteristic can be

fixed over the full temperature range. The sensor can

compensate for linear temperature coefficients ranging

from about

−3100 ppm/K up to 400 ppm/K and qua-

dratic coefficients from about

−5 ppm/K² to 5 ppm/K².

Please refer to Section 4.3. on page 17 for the recom-

mended settings for different linear temperature coeffi-

cients.

Sensitivity

The SENSITIVITY register contains the parameter for

the multiplier in the DSP. The Sensitivity is program-

mable between

−4 and 4. For V

DD = 5 V, the register

can be changed in steps of 0.00049. Sensitivity = 1

corresponds to an increase of the output voltage by

VDD if the ADC-READOUT increases by 2048.

For all calculations, the digital value from the magnetic

field of the A/D converter is used. This digital informa-

tion is readable from the ADC-READOUT register.

VOQ

The VOQ register contains the parameter for the adder

in the DSP. VOQ is the output voltage without external

magnetic field (B = 0 mT, respectively ADC-READOUT

= 0) and programmable from

−V

DD up to VDD. For VDD

= 5 V, the register can be changed in steps of 4.9 mV.

Note: If VOQ is programmed to a negative voltage, the

maximum output voltage is limited to:

For calibration in the system environment, a 2-point

adjustment procedure (see Section 2.3.) is recom-

mended. The suitable Sensitivity and VOQ values for

each sensor can be calculated individually by this pro-

cedure.

Magnetic Field Range

RANGE

−30 mT...30 mT

−40 mT...40 mT

−60 mT...60 mT

−75 mT...75 mT

−80 mT...80 mT

−90 mT...90 mT

−100 mT...100 mT

−150 mT...150 mT

−3 dB Frequency

FILTER

80 Hz

160 Hz

500 Hz

1 kHz

2 kHz

∆V

OUT * 2048

∆ADC-READOUT * V

Sensitivity =

VOUTmax = VOQ + VDD

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