The ATS635LSE and ATS636LSE programmable, true power-on state (TPOS), sensors are an optimized Hall-effect IC and magnet combination that switch in response to magnetic signals created by ferrous targets in gear-tooth sensing and proximity applications. The devices are externally programmable. A wide range programmability is available on the magnetic operate point (BOP) while theof hysteresis remains fixed. This advanced feature allows for optimization of the sensor switch point and can drastically reduce the effects of mechanical placement tolerances found in production environments . A proprietary dynamic offset cancellation technique, with an internal high-frequency clock, reduces the residual offset voltage, which is normally caused by device overmolding, temperature dependencies, and thermal stress. Having the Hall element and amplifier in a single chip minimizes many problems normally associated with low-level analog signals. This sensor system is ideal for use in gathering speed or position information using gear-tooth-based configurations, or for proximity sensing with ferrous targets. The ATS635LSE switches HIGH in the presence of a ferrous target or tooth and switches LOW in the presence of a target valley, window, or when the ferrous target is removed. The ATS636LSE has the opposite polarity and switches LOW in the presence of a ferrous target