HAL-APB-V1.5 Datasheet, PDF (24/59 Pages) Micronas – Application Board HAL-APB V1.x

HAL1820, HAL24xy, HAL28xy, HAL36xy, HAL38xy
Application Board HAL-APB V1.x
8. HAL 1820
APPLICATION NOTE
The HAL 1820 is a universal magnetic field sensor with a linear output, based on the
Hall effect. Magnetic field, perpendicular to the branded side of the sensor provides a
output voltage direct proportional to the applied magnetic flux through the Hall plate
and proportional to the supply voltage (ratiometric behavior). Details on features and
specification are described in the data sheet.
8.1. Programming interface
The sensor is programmed via supply voltage modulation. After detecting a command,
the sensor reads or writes the memory and answers with a digital signal on the output
pin.
A logical “0“ is coded as no level change within the bit time. A logical “1“ is coded as a
level change of typically 50% of the bit time. After each bit, a level change occurs (see
Fig. 8–1).
The serial telegram is used to transmit the EEPROM content, error codes and digital
values of the magnetic field from and to the sensor.
t_bbit
t_bbit
or
logical 0
logical 1
t_bbit
or
t_bhb t_bhb
t_bbit
t_bhb t_bhb
Fig. 8–1: Definition of logical 0 and 1 bit
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Oct. 8, 2012; APN000055_003EN
Micronas