Micronas > HAL 300: Differential Hall Effect Sensor IC

HAL 300: Differential Hall Effect Sensor IC

HAL 300 Description

The HAL^® 300 from Micronas is a Differential Hall Switch produced in CMOS technology. The sensor includes 2 temperature-compensated Hall plates (2.05 mm apart) with active offset compensation, a differential amplifier with a Schmitt trigger, and an open-drain output transistor.

The HAL 300 differential sensor responds to spatial differences of the magnetic field. The Hall voltages at the two Hall plates, S₁ and S₂, are amplified with a differential amplifier. The differential signal is compared with the actual switching level of the internal Schmitt trigger. Accordingly, the output transistor is switched on or off.

The sensor has a bipolar switching behavior and requires positive and negative values of delta B = BS₁–BS₂ for correct operation.

For applications in which a magnet is mounted on the back side of the package (back-biased applications), the HAL 320 is recommended.

The active offset compensation leads to constant magnetic characteristics over supply voltage and temperature.

The sensor is designed for industrial and automotive applications and operates with supply voltages from 4.5 V to 24 V in the ambient temperature range from –40 °C up to 150 °C.

The HAL 300 is available in the SMD-package SOT89B-2 and in the leaded versions TO92UA-3 and TO92UA-4.

HAL 300 System Architecture

This Hall effect sensor is a monolithic integrated circuit with 2 Hall plates 2.05 mm apart that switches in response to differential magnetic fields. If magnetic fields with flux lines perpendicular to the sensitive areas are applied to the sensor, the biased Hall plates force Hall voltages proportional to these fields. The difference of the Hall voltages is compared with the actual threshold level in the comparator. The temperature-dependent bias increases the supply voltage of the Hall plates and adjusts the switching points to the decreasing induction of magnets at higher temperatures. If the differential magnetic field exceeds the threshold levels, the open drain output switches to the appropriate state. The builtin hysteresis eliminates oscillation and provides switching behavior of the output without oscillation.

HAL 300 Block Diagram

*Datasheets may be updated without notification

HAL 300 Features

Distance between Hall plates: 2.05 mm
Operates from 4.5 V to 24 V supply voltage
Switching offset compensation at 62 kHz
Overvoltage protection
Reverse-voltage protection at V DD-pin
Short-circuit protected open-drain output by thermal shutdown
Operates with magnetic fields from DC to 10 kHz
Output turns low with magnetic south pole on branded side of package and with a higher magnetic flux density in sensitive area S 1 as in S 2
On-chip temperature compensation circuitry minimizes shifts of the magnetic parameters over temperature and supply voltage range
The decrease of magnetic flux density caused by rising temperature in the sensor system is compensated by a built-in negative temperature coefficient of hysteresis
EMC corresponding to ISO 7637