Micronas Slashes Cost and Qualification Time With Fully Programmable Hall Effect Switch for Automotive Applications

    FREIBURG, Germany, Feb. 19 -- Micronas, a leading supplier of
IC solutions for multimedia, consumer and automotive electronics, introduced
the HAL 1500, a fully programmable hall switch aimed at automotive
applications requiring position sensing like sunroofs, windows, seat positions
and safety belts.
    "Until now manufacturers were using a great variety of different sensors
with fixed switching levels and output modes to fulfill the different demands
of various applications. The HAL 1500 covers all applications with one fully
integrated switch, which significantly reduces costs," said Peter Zimmermann,
automotive market manager at Micronas. "This also means that now only one
qualification process is needed for each single switch."
    The fully integrated switch allows system manufacturers to program
magnetic switching levels and output modes through simple end-of-line
programming of the on-chip EEPROM. The switch acts as a unipolar or latching
switch with normal or inverted output, making rotation measurements possible
to detect, as in the rotation of camshafts, for example.
    "Due to its programmability, the switch offers greater flexibility and a
much higher accuracy than fixed-function devices. This allows Micronas to
access and expand into new markets for hall effect switches," added
Zimmermann.
    Higher accuracy is a key issue for many applications in the car such as
seat position sensing in conjunction with car safety systems. With position
sensing information, the airbag controller knows the exact location of the
driver or passenger and can compute how fast the airbag must be deployed to
provide optimal protection in case of an accident.
    The HAL 1500 features an on-chip sensor element, DSP and EEPROM. With the
help of the data stored in the EEPROM, the DSP computes the behavior of the
switch. Non-programmable switches have wide-spread magnetic switching levels
due to the variations in the production process. To avoid these part-to-part
variations each individual sensor can be adjusted in the HAL 1500 to meet the
demands of each application. As a result of the sensors' programmability,
production variations are no longer problematic and the manufacturer's
application is much more accurate.
    Where moderate resolution is required, it is possible to program the HAL
1500 as a pseudo linear hall sensor. The PWM output signal delivers a 4-bit
resolution, which is enough for applications like four-level regulation of the
headlight and multi-level wiper regulation. As a pseudo linear hall sensor,
the HAL 1500 is the device of choice for cost sensitive applications where
high 12-bit resolution is not required. For applications requiring higher bit
resolution, Micronas offers the HAL 8xx families of regular linear hall
sensors.
    The HAL 1500 switch is available in SOT89-SMD and TO92UA through contact
packages. In high quantities of 1 million and up, the sensors sell for
US$0.75 each.

    Glossary
    Unipolar Hall Switch:  These types of switches require a single polarity
magnetic field for operation (a south pole or a north pole). When the magnetic
flux density increases above the operating point, it switches on.
    Latching Hall Switch:  These switches need both north and south pole for
operation. If no magnetic field is sensed the switch remains in its last
position.
    Inverted output:  Normally the sensor switches from high to low if B >
Bon. A switch with an inverted output switches from low to high if B > Boff.

    About Micronas
    Micronas (SWX Swiss Exchange: MASN)
(Prime Standard Segment Frankfurt: MNSN), a semiconductor company group with
worldwide operations, is a leading supplier of cutting-edge IC and sensor
system solutions for consumer electronics, multimedia and automotive
electronics. The holding is headquartered in Zurich (Switzerland). Currently,
the Micronas group employs about 1700 people. In 2002, it generated over CHF
707 Million in sales. For more information on Micronas and its products,
please visit http://www.micronas.com.