UGN-3040T

The UGN-3040T has the following features including 4.5 V to 24 V Operation;Switched by Small Permanent Magnets;High Reliability-No Moving Parts;Small Size;Output Compatible with All Digital Logic Families;Constant Output Amplitude.

THE EXTREME SENSITIVITY of Type 3040 Hall Effect switches recommends their use with small, inexpensive magnets or in applications requiring relatively large distances between magnet and Hall cell. The magnetically activated electronic devices are available with two operating temperature ranges and in two three-pin plastic packages.Each Hall Effect circuit includes a voltage regulator, Hall voltage generator, signal amplifier,Schmitt trigger, and open-collector output on a single silicon chip.The on-board regulator permits operation over a wide range of supply voltages. All four ICs work with supply voltages of 4.5 to 24 V.The switches' output can sink up to 20 mA at a conservatively rated  repetition rate  of  100 kHz.They can be used directly with bipolar or MOS logic circuits. Selected devices, with outputs capable of sinking 50 mA, are available on special order.

The most common modes of operation are head-on and slide-by. As shown in the drawing at right,the magnet's polar axis is the centerline of the Hall Effect package. Change of operating states in the head-on mode is accomplished by decreasing or increasing the distance between the magnet and Hall cell.The output transistor is OFF when the flux density of the magnetic field perpendicular to the surface of the chip is below threshold (the operate point).When flux density reaches the operate point, the output transistor switches ON and is capable of sinking 25 mA of current.Note that the device is turned ON by presenting the south pole of the magnet to the branded face of the package, which is opposite the side with the ejector pin indentation. With the branded side facing you and the pins pointing down, pinouts are, from left to right: (1) Vcc, (2) GND, (3) Vout.The output transistor is switched OFF when flux density of the magnetic field falls below the release point, which is less than the operate point. Hysteresis, as illustrated in the Transfer Characteristics graph, prevents ambiguity and oscillation.