AH5798 Datasheet | Diodes Incorporated

Features - - - - - - - - - - - Support single-phase full wave DC fan driver Built-in Hall sensor input amplifier Low voltage startup ( Vdd=1.8V ) Lock detection and automatic self-restart Soft switching for low noise DC fans Without external timing capacitor, Reduces the numbers of external ponent required Thermal protection FG output Low profile package: SOT89-5L SOT89-5L: Available in “Green” Molding pound (No Br, Sb) Lead Free Finish/ Ro HS pliant (Note 1) General Description 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. Applications - - - 3.3V / 5V Min. BLDC Cooling Fans Net-Book/ Note-Book DC fans Low Voltage/ Low Power BLDC Motors Typical Application Circuit SYSTEM POWER .. SYSTEM POWER Vdd D1 C1 Dz FG 10Kohm O1 O2 V SS - Reverse connection of power supply may break the device. A countermeasure is needed such as using reverse power protection diode D1 between power supply and Vdd terminal. In such case of using reverse power protection diode D1 because of there is no way to return current to power supply, please take necessary measures like below. - Connect Dz (Zener diode) between Vdd and Vss terminal, not to exceed the absolute maximum rating voltage. - Connect a capacitor C1 between Vdd and Vss terminal, to make the path of return current to power supply. The...