Hall Effect Sensors 3503
Description Of Hall Effect Sensors 3503
The UGN3503LT, UGN3503U, and UGN3503UA Hall-effect sensors accurately track extremely small changes in magnetic flux density changes generally too small to operate Hall-effect switches. As motion detectors, gear tooth sensors, and proximity detectors, they are magnetically driven mirrors of mechanical events. As sensitive monitors of electromagnets, they can effectively measure a system’s performance with negligible system loading while providing isolation from contaminated and electrically noisy environments. Each Hall-effect integrated circuit includes a Hall sensing element, linear amplifier, and emitter-follower output stage. Problems associated with handling tiny analog signals are minimized by having the Hall cell and amplifier on a single chip. Three package styles provide a magnetically optimized package for most applications. Package suffix ‘LT’ is a miniature SOT-89/TO-243AA transistor package for surface-mount applications; suffix ‘U’ is a miniature three-lead plastic SIP, while ‘UA’ is a three-lead ultra-mini-SIP. All devices are rated for continuous operation over the temperature range of -20°C to +85°C.
Block Diagram Of Hall Effect Sensors 3503
Feature Of Hall Effect Sensors 3503
- Extremely Sensitive
- Flat Response to 23 kHz
- Low-Noise Output
- 4.5 V to 6 V Operation
- Magnetically Optimized Package
Operation Of Hall Effect Sensors 3503
The output null voltage (B = 0 G) is nominally one-half the supply voltage. A south magnetic pole, presented to the branded face of the Halleffect sensor will drive the output higher than the null voltage level. A north magnetic pole will drive the output below the null level. In operation, instantaneous and proportional output-voltage levels are dependent on magnetic flux density at the most sensitive area of the device. Greatest sensitivity is obtained with a supply voltage of 6 V, but at the cost of increased supply current and a slight loss of output symmetry. The sensor’s output is usually capacitively coupled to an amplifier that boosts the output above the millivolt level. In two applications shown, a permanent bias magnet is attached with epoxy glue to the back of the epoxy package. The presence of ferrous material at the face of the package acts as a flux concentrator. The south pole of a magnet is attached to the back of the package if the Hall-effect IC is to sense the presence of ferrous material. The north pole of a magnet is attached to the back surface if the integrated circuit is to sense the absence of ferrous matrial. Calibrated linear Hall devices, which can be used to determine the actual flux density presented to the sensor in a particular application, are available.