DATA SHEET HAL 2850
Micronas July 25, 2013; DSH000160_002EN 5
Linear Hall-Effect Sensor with PWM Output
Release Note: Revision bars indicate significant
changes to the previous edition.
1. Introduction
The HAL 2850 is a member of the Micronas family of
programmable linear Hall-effect sensors.
The HAL 2850 features a temperature-compensated
Hall plate with spinning current offset compensation,
an A/D converter, digital signal processing, an
EEPROM memory with redundancy and lock function
for the calibration data, and protection devices at all
pins. The internal digital signal processing is of great
benefit because analog offsets, temperature shifts,
and mechanical stress do not degrade digital signals.
The easy programmability allows a 2-point calibration
by adjusting the output signal directly to the input sig-
nal (like mechanical angle, distance, or current). Indi-
vidual adjustment of each sensor during the cus-
tomer’s manufacturing process is possible. With this
calibration procedure, the tolerances of the sensor, the
magnet, and the mechanical positioning can be com-
pensated in the final assembly.
In addition, the temperature-compensation of the Hall
IC can be fit to all common magnetic materials by pro-
gramming first- and second-order temperature coeffi-
cients of the Hall sensor sensitivity. It is also possible
to compensate offset drifts over temperature gener-
ated by the customer application with a first-order tem-
perature coefficient of the sensor offset. This enables
operation over the full temperature range with high
accuracy.
For programming purposes, the sensor features a pro-
gramming interface with a Biphase-M protocol on the
DIO pin (output).
In the application mode, the sensor provides a continu-
ous PWM signal.
1.1. Features
– High-precision linear Hall-effect sensor
– Spinning current offset compensation
– 20 bit digital signal processing
– ESD protection at DIO pin
– Reverse voltage and ESD protection at VSUP pin
– Various sensor parameter are programmable (like
offset, sensitivity, temperature coefficients, etc.)
– Non-volatile memory with redundancy and lock
function
– Programmable temperature compensation for sensi-
tivity (2nd order) and offset (1st order)
– PWM frequency programmable from 31.25 Hz up to
2kHz
– PWM resolution between 11 bit and 16 bit depend-
ing on the PWM frequency
– The magnetic measurement range over tempera-
ture is adjustable from 24 mT up to 96 mT
– On-board diagnostics (overvoltage, output current,
overtemperature, signal path overflow)
– Power-on self-test covering all memories
– Biphase-M interface (programming mode)
– Sample accurate transmission for certain periods
(Each PWM period transmits a new Hall sample)
– Digital readout of temperature and magnetic field
information in calibration mode
– Open-drain output with slew rate control (load inde-
pendent)
– Programming and operation of multiple sensors at
the same supply line
– High immunity against mechanical stress, ESD, and
EMC
1.2. Major Applications
– Contactless potentiometers
– Angular measurements
(e.g.; torque force, pedal position, suspension level,
headlight adjustment; or valve position)
– Linear position
– Current sensing for motor control, battery manage-
ment