Production£º

datasheet.pdf

The Differential Hall Sensor IC detects the motion and position of ferromagnetic and permanent magnet structures by measuring the differential flux density of the magnetic field¡£ To detect ferromagnetic objects the magnetic field must be provided by a back biasing permanent magnet £¨south or north pole of the magnet attached to the rear unmarked side of the IC package£©¡£
¡¡¡¡Using an external capacitor the generated Hall voltage signal is slowly adjusted via an active high pass filter with a low cut-off frequency¡£ This causes the output to switch into a biased mode after a time constant is elapsed¡£ The time constant is determined by the external capacitor¡£ Filtering avoids ageing and temperature influence from Schmitt-trigger input and eliminates device and magnetic offset¡£
¡¡¡¡The TLE 4921-5U can be exploited to detect toothed wheel rotation in a rough environment¡£ Jolts against the toothed wheel and ripple have no influence on the output signal¡£
¡¡¡¡Furthermore£¬ the TLE 4921-5U can be operated in a two-wire as well as in a three-
¡¡¡¡wire-configuration¡£
¡¡¡¡The output is logic compatible by high/low levels regarding on and off¡£
¡¡¡¡Circuit Description £¨see Figure 2£©
¡¡¡¡The TLE 4921-5U is comprised of a supply voltage reference£¬ a pair of Hall probes spaced at 2¡£5 mm£¬ differential amplifier£¬ filter for offset compensation£¬ Schmitt trigger£¬ and an open collector output¡£
¡¡¡¡The TLE 4921-5U was designed to have a wide range of application parameter variations¡£ Differential fields up to   80 mT can be detected without influence to the switching performance¡£ The pre-induction field can either come from amagnetic south or north pole£¬ whereby the field strength up to 500 mT or more will not influence the switching points¡£ The improved temperature compensation enables a superior sensitivity and accuracy over the temperature range¡£ Finally the optimised piezo compensation and the integrated dynamic offset compensation enable easy manufacturing and elimination of magnet offsets¡£
¡¡¡¡Protection is provided at the input/supply £¨pin 1£© for overvoltage and reverse polarity and against over-stress such as load dump£¬ etc¡££¬ in accordance with ISO-TR 7637 and DIN 40839¡£ The output £¨pin 2£© is protected against voltage peaks and electrical disturbances¡£
Sumzi

Contact person:

Frances New

Phone:+86-755-81832961

Fax:+86-755-83299282

Email:sumzi@sumzi.com

MSN:sumzi_frances@msn.com

http://www.sumzi.com