The AH5798 is a single chip solution for driving single-coil brush-less DC fans and motors. The AH5798 employs a bidirectional full bridge driver output stage for single coil fan motor applications. The soft switching driver generates the low noise operating for DC fans. The device includes features such as Rotor Lock Protection with rotor lock detection and automatic self-restart to avoid damage to the coil when the rotor is blocked. The AH5798 also offers an externally controlled Tachometer (Frequency Generator Pin) open -drain output which makes it easier to connect with external interface such as hardware monitoring. The FG is the magnetic change frequency. The device is packaged in SOT89-5L for SMT applications in DC fans.