UGN-3077T

The UGN-3077T has the following features including Symmetrical Output;For Use with Multipole Ring Magnets;High Reliability-No moving Parts;Small Size;Output Compatible with All Digital Logic Families;4.5 V to 24 V Operation;High Hysteresis Level Minimizes Stray-Field Problems.

The Sprague Type 3077 latching Hall Effect sensor is a bipolar integrated circuit designed for applications requiring a symmetrical duty cycle, such as control of high-efficiency brushless do motors. Typically, the latch is used to sense the matched flux densities of alternating polarity created by small, inexpensive multipole ring magnets.The integrated circuit includes a Hall voltage generator, operational amplifier, Schmitt trigger, bipolar output transistor, and voltage regulator. The regulator allows use of the IC with supply voltages ranging from 4.5 V to 24 V.The output transistor saturates when the Hall element is exposed to a magnetic flux density equal to or greater than its ON threshold. The NPN output remains ON until magnetic flux density of equal strength but opposite polarity crosses the sensor's OFF threshold.

Under power-up conditions, and in the absence of an externally applied magnetic field, the output transistor of most Type 3077 latches is ON and capable of sinking 25 mA of current. This is, however, a formally ambiguous state and should be treated as such.In normal operation, the output transistor turns ON as the strength of the magnetic field perpendicular to the surface of the chip reaches the Operate Pbint. The output transistor switches OFF as magnetic field reversal takes magnetic flux density to the Release Point.All Hall Effect integrated circuits are susceptible to mechanical stress effects. Caution should be exercised to minimize the application of stress to the leads or the epoxy package. Use of epoxy glue is recommended.Other types may deform the epoxy package.To prevent permanent damage to the Hall cell, heat-sink the leads during hand-soldering. Recommended maximum conditions for wave soldering are shown in the graph at right. Solder flow should be no closer than 0.125" (3.18 mm) to the epoxy package.