LED Driver with Integrated Micropower Hall-Effect Switch

The APS13568 is an integrated circuit that combines an ultrasensitive, omnipolar, micropower Hall-effect switch with a linear programmable current regulator providing up to 150 mA to drive high brightness LEDs. The omnipolar Hall-effect switch provides contactless control of the regulated LED current, which is set by a single reference resistor. This highly integrated solution offers high reliability and ease of design compared to a discrete solution.

The Hall-effect switch operates with either a north or a south magnetic pole. The switch output polarity can be set with an external pulldown on the POL input pin. This allows the user to select whether the APS13568 switch output goes low when a
magnet is present or when the magnetic field is removed. Chopper stabilization provides low switchpoint drift over temperature.

The LED is turned on when the EN input goes low. This active low input can be connected directly to the Hall switch output, SO, to turn the LED on when the switch output goes low. This flexible solution allows the user to connect additional slave
switches, LED drivers, PWM, or microprocessor inputs to control when the LED is on. Optionally, an external capacitor can be used to adjust the fade-in/fade-out feature.

On-board protection for shorts to ground and thermal overload prevents damage to the APS13568 and LED string by limiting the regulated current until the short is removed and/or the chip temperature has reduced below the thermal threshold.

The device is packaged in an 8-pin SOICN (LJ) with an exposed pad for enhanced thermal dissipation. It is RoHS-compliant, with100% matte-tin leadframe plating.

The APS13568 is available in an “E” temperature version (up to 85°C) for industrial and consumer applications, as well as a “K” temperature version (up to 125°C) that is qualified per AEC-Q100 for automotive applications.