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.