The ATS617 gear-tooth sensor IC is a peak-detecting device that uses automatic gain control and an integrated capacitor to provide extremely accurate gear edge detection down to low operating speeds. Each device consists of a high-temperature plastic shell that holds together a samarium-cobalt pellet, a pole piece, and a differential open-collector Hall IC that has been optimized to the magnetic circuit. This small package can be assembled simply and used in conjunction with a wide variety of gear shapes and sizes.
The technology used for this device is Hall-effect based. The device incorporates a dual-element Hall IC that switches in response to differential magnetic signals created by ferromagnetic targets. The sophisticated processing circuitry contains an A-to-D converter that self-calibrates (normalizes) the internal gain of the device to minimize the effect of air gap variations. The patented peak-detecting filter circuit provides immunity to magnet and system offsets and has the ability to discriminate relatively fast changes such as those caused by tilt, gear wobble, and eccentricities. This easy-tointegrate solution provides first falling edge detection and stable operation to extremely low rpm. The ATS617 can be used as a replacement for the ATS616.
The ATS617 is ideal for use in systems that gather speed, position, and timing information using gear-tooth-based configurations. This device is particularly suited to those applications that require extremely accurate duty cycle control or accurate edge-detection, such as automotive camshaft sensing.
