HAL856 Datasheet, PDF (10/42 Pages) Micronas – Programmable Linear Hall-Effect Sensor with Arbitrary Output Characteristic (2-Wire)

HAL 856
DATA SHEET
Mode
The MODE register consists of four “sub”-registers
defining the magnetic and output behavior of the sen-
sor. The RANGE bits are the three lowest bits of the
MODE register; they define the magnetic field range of
the A/D converter. The next three bits (FILTER) define
the −3 dB frequency of the digital low pass filter. The
next sub-register is the FORMAT register, and it
defines the different output formats as described
below. This sub-register also consists of 3 bits. The
last three MSBs define the OUTPUT PERIOD of the
PWM signal.
Range
Table 2–1: RANGE register definition
Magnetic Field 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
Bit Setting
0
4
5
1
6
2
7
3
Output Format
The HAL856 provides two different output formats: a
PWM and Biphase-M output.
PMW output is a pulse width modulated output. The
signal is defined by the ratio of pulse width to pulse
period.
The Biphase-M output is a serial protocol. A logical “0”
is coded as no output level change within the bit time.
A logical “1” is coded as an output level change
between 50% and 80% of the bit time. After each bit,
an output level change occurs (see Section 3.6.1. on
page 26).
Table 2–3: OUTPUT FORMAT register definition
Output Format
Bit Setting
PWM
2
Biphase-M
4¹⁾
Biphase-M (test)
5²⁾
1) _{In case of OUTPUT FORMAT = 4 the continuous}
Biphase-M output will be active after locking the
device. In order to test the Biphase-M output with
non-locked sensors OUTPUT FORMAT = 5 has
to be used.
2) _{writing OUTPUT FORMAT = 5 will activate the}
Biphase-M output for test purpose. The test can
be deactivated by switching the device off. It is
not possible to communicate with the sensor after
activation of test mode.
Filter
Table 2–2: FILTER register definition
−3 dB Frequency
80 Hz
160 Hz
500 Hz
1 kHz
2 kHz
Bit Setting
0
1
2
3
4
10
March 23, 2010; DSH000142_002EN
Micronas