The invention relates to a Hall-effect gear tooth sensor IC, which is used in the fields of distance detection, speed detection, rotation speed detection and so on. The Hall-effect gear tooth sensor IC comprises a reverse protection circuit, a voltage stabilizing circuit and a signal processing circuit, wherein the reverse protection circuit is connected with a power supply; and the signal processing circuit is provided with a pin C+ and a pin C-. The signal processing circuit is characterized in that the signal processing circuit consists of a Hall voltage generator, a differential amplifier, a band-pass filter, a hysteresis comparator circuit, a open-collector output stage, a grounding wire and necessary connection circuits, wherein the Hall voltage generator, the differential amplifier, the band-pass filter, the hysteresis comparator circuit and the open-collector output stage are connected in sequence. The Hall-effect gear tooth sensor IC provided by the invention is simple in size, convenient in use, and has the advantages of high sensitivity, high reliability, high resistance to vibration, radio frequency and electromagnetic interference, and good consistency.