The US890/891 is a one-chip solution for driving two-coil brushless DC motors and fans. Based on the advanced Melexis CMOS process, the IC contains a Hall-effect sensor, dynamic offset correction and powerful output drivers with 1200mA peak output current capability. Specially designed for driving large fans, the device is optimized for low start-up voltage. Frequency Generator or Rotation Detection is available. The open-drain output makes easier the connectivity with any external interface such as hardware monitoring or Super I/O IC. These features are combined with the Melexis patented no-VDD design to fit the IC in a small 4pin VK package.