The ATS616 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 package 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 circuit is Hall-effect based. The chip 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 eliminates 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-to-integrate solution provides first-tooth detection and stable operation to extremely low rpm. The ATS616 can be used as a replacement for the ATS612LSB, eliminating the external peak-holding capacitor needed by the ATS612LSB.
The ATS616 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.
