AH5794-WU-7 Diodes Incorporated

AH5794 SINGLE PHASE HALL EFFECT LATCH FAN MOTOR DRIVER Description Pin Assignments The AH5794 is a single chip solution for driving single-coil (Top View) brushless direct current (BLDC) fans and motors. The integrated full-bridge driver output stage uses soft switching to FG 1 6 NC minimize audible switching noise and electromagnetic interference (EMI) providing a low noise solution. 2 5 V V DD SS Low operating voltage down to 1.8V allows motor speed to be O2 3 4 O1 controlled by varying the supply voltage. TSOT26 To help protect the motor coil, the AH5794 provides Rotor Lock Protection which shuts down the output drive if rotor lock (Top View) is detected. The device automatically re-starts when the rotor lock is removed. Over temperature shutdown provides FG NC 1 6 thermal protection for the device. 2 O2 V 5 DD A Tachometer output is provided by open-drain Frequency V 3 4 O1 SS Generator (FG) Pin which allows external interface to monitor motor rotation or speed. The FG output is the magnetic U-DFN2020C-6 change frequency. The AH5794 is available in space saving and low profile TSOT26 and U-DFN2020C-6 packages. Applications Features 3V/ 3.3V/ 5V BLDC Cooling Fans Supports single-coil full-wave BLDC fan drivers Netbook/ Notebook BLDC fans Built-in Hall sensor and input amplifier Instruments cooling fans Operating voltage: 1.8V to 6V V voltage speed control Low Voltage/ Low Power BLDC Motors DD Soft switching for low noise DC fan motor applications Rotor Lock Protection (Lock detection, output shutdown and automatic re-start) Thermal protection Tachometer (FG) output No external timing capacitor - Reduces the numbers of external components required Low profile package: TSOT26 and U-DFN2020C-6 Halogen and Antimony free Green packages. Lead Free Finish/ RoHS Compliant 1 of 13 March 2012 AH5794 Diodes Incorporated www.diodes.com Document number: DS35809 Rev. 1 - 2 NEW PRODUCT AH5794 SINGLE PHASE HALL EFFECT LATCH FAN MOTOR DRIVER Typical Application Circuit Pin Descriptions Pin Name Description V Power supply pin DD V Ground pin SS O1 Output driving & sinking pin O2 Output driving & sinking pin NC No connection FG Frequency generator (Note 1) Notes: 1. The FG output is the same as the magnetic change frequency. 2 of 13 March 2012 AH5794 Diodes Incorporated www.diodes.com Document number: DS35809 Rev. 1 - 2 NEW PRODUCT