FR9855 Datasheet | Fiti

Description The FR9855 is a synchronous step-down DC/DC converter with fast constant on time (FCOT) mode control. The device provides 4.5V to 18V input voltage range and 5.5A continuous load current capability. Operation frequency depends on Input and output voltage condition. At light load condition, the FR9855 can operate at power saving mode to support high efficiency and reduce power loss. The FR9855 fault protection includes cycle-by-cycle current limit, short circuit protection, UVLO and thermal shutdown. The soft-start function prevents inrush current at turn-on. The FR9855 use fast constant on time control that provides fast transient response, the noise immunity and all kinds of very low ESR output capacitor for ensuring performance stabilization. The FR9855 is offered in SOP-8 (Exposed Pad) and TDFN-10 (3mm x 3mm) packages, which provides good thermal conductance. Pin Assignments SP Package (SOP-8 Exposed Pad) Features Low RDS(ON) Integrated Power MOSFET (70mΩ/38mΩ) Wide Input Voltage Range: 4.5V to 18V Output Voltage Range: 0.765V to 8V 5.5A Output Current FCOT Mode Enables Fast Transient Response Pseudo 630k Hz Frequency Power Good Function (for FR9855SP Only) Input Under Voltage Lockout Adjustable Soft Start Function Cycle-by-Cycle Current Limit Hiccup Short Circuit Protection Over Temperature Protection with Auto Recovery SOP-8 Exposed Pad and TDFN-10(3mmx3mm) Packages Applications STB (Set-Top-Box) LCD Display, TV Distributed Power System Networking, XDSL Modem Ordering Information FR9855- Package Type SP: SOP-8 (Exposed Pad) DA: TDFN-10(3mm x 3mm) DA Package (TDFN-10)(3mm x 3mm) Figure 1. Pin Assignments of FR9855 FR9855-Preliminary 0.4-DEC-2016 Typical Application Circuit Figure 2. Application Circuit for SOP-8 Exposed Pad Package VIN=12V, the remended BOM list is as below. VOUT C1 R1 R2 1.05V 10µF MLCC 7.87kΩ 21kΩ C2 C6 10µF MLCC 5p F~33p F 1.2V 10µF MLCC 12kΩ 21kΩ 10µF MLCC 5p F~33p F 1.8V 10µF MLCC 28kΩ 21kΩ 10µF...