MLX90248 Datasheet, PDF (5/11 Pages) Melexis Microelectronic Systems – Micropower & Omnipolar Hall Switch

MLX90248
Micropower & Omnipolar™ Hall Switch
9 Detailed General Description
The MLX90248 is originally used in mobile phone applications for open/close lid detection (slide and jack-
knife phone type). The goal of this detection is to switch on or off the application if the lid is opened or closed,
in order to save battery power.
The same operation principle can be simply applied to any other battery-powered device with a lid/cover like
laptop, digital cameras and camcorders.
By the use of a very high sensitivity Hall sensor, a very small and cheap magnet is enough to trigger the
MLX90248, hence it can easily replace reed switch.
The major benefit of using a Hall sensor is to provide “electronic” commutation, which is bounce-free, more
reliable and with increased lifetime compared to usual mechanical contacts.
10 Unique Features
The MLX90248 exhibits “Omnipolar” magnetic characteristics. It means the device reacts to both North and
South magnetic pole. The purpose is to detect the presence of any magnetic field applied on the device.
This mode of operation simplifies customer production processes by avoiding the need to detect the Hall
sensor pole active on the magnet used in the application.
Taking the example of a generic Hall sensor “south pole active”, during its production, the customer must
detect the south pole of the application magnet and face it to the device to enable the output to be turned on
and off. Without any magnet pole detection system, the incorrect magnetic pole (north in this example) could
be faced to the device which would fail the application.
Therefore, the “Omnipolar” magnetic behaviour helps customers by removing the need of magnet pole
detection system during production phase.
The “Micropower” feature makes the MLX90248 especially suitable for battery-powered device as it combines
low voltage operation and low current consumption. By using a sleep/awake strategy managed internally, the
power consumption is drastically reduced. To make a comparison, the MLX90248 consumes 100 times less
power than the generic low voltage Melexis Hall sensor US3881.
As well as Thin SOT package, the MLX90248 is now delivered in an ultra thin UTQFN package. This new
leadless package only requires 3mm² PCB surface and is 0.43mm maximum thick, which is particularly
important in design where space-saving and miniaturisation are the critical factors.
3901090248
Rev 012
Page 5 of 11
Data Sheet
Sept/06