The SC9625 has a combination of two Hall elements, a differential amplifier and evaluating circuitry, all on a single chip. Evaluating field difference instead of absolute field strength means that disruptive effects, like temperature drifts, manufacturing tolerances and magnetic environment are minimized.
The IC is designed for use under aggressive conditions found in automotive applications. A small permanent biasing magnet is required for sensing ferromagnetic gear wheels of various shapes. Correct switching for even the smallest field differences between tooth and gap is guaranteed.
The Differential Hall Sensor IC detects the motion and position of ferromagnetic and permanent magnet structures by measuring the differential flux density of the magnetic field. Changes in field strength at the device face, which are induced by a moving target, are sensed by the two integrated Hall transducers. The transducers generate signals that are differentially amplified by on-chip electronics. This differential design provides immunity to radial vibration within the operating air gap range of the SC9625, by rejection of the common mode signal. Steady-state magnet and system offsets are eliminated using an on-chip differential band-pass filter. This filter also provides relative immunity to interference from electromagnetic sources.
The SC9625 can be exploited to detect toothed wheel rotation in a rough environment. Jolts against the toothed wheel and ripple have no influence on the output signal. Furthermore, the device can be operated in a two-wire as well as in a three wire-configuration.
The device is packaged in a 4-pin plastic SIP. It is lead (Pb) free, with 100% matte tin plated leadframe.