US890

US890 0 / US891 Two-Coil Fan Driver – High Ou utput Current Features and Benefits 0 0 0 0 0 0 0 0 Peak output current up to 1200mA Low start-up voltage Low output resistance High sensitivity integrated Hall Se en n sor Power-efficient CMOS and power MOSFETs Built-in output protection clamping diode Locked rotor protection and auto-r estart Integrated tachometer (US890) or alarm (US891) signal protected output 0 Low cost 0 2-coil fan driver with FG/RD output in RoHS Compliant 4-pin VK packa ge age Application Examples 0 0 0 0 5V/12V DC brushless moto r/fan PC, server, laptop cooling f fan Power supply cooling fan Large and small fan size Ordering Code Product Code US891 US890 Temp Tempera ture Code erature E E Package Code VK VK Optio Option n Code AAA-000 AAA-000 Packing Form Code BU BU Legend: Temperature Code: Package Code: Packing Form: Ordering example: C to 85° C E for Temperature Range Range -40° VK for Plastic Single in Line BU for for Bulk US891E US891 EVK VK-AAA-000-BU 1 Functional Diagram 2 General Descriptio n The US890/891 is a one-chip s olution for driving two-coil brushless DC motors an and d fans. Based on the advanced Melexi s CMOS process, the IC contains a Hall-effect se n sor, dynamic en offset correction and powerful out out put drivers with 1200mA peak output current cap ap ability. Specially designed for driving la rge fans, the device is optimized for low star t-up voltage. Frequency Generator or Rotati on Detection is available. The open-drai...