The FR9811 is a synchronous step-down DC/DC

converter with fast constant on time (FCOT) mode

control. The device provides 4.5V to 23V input

voltage range and 2A continuous load current

capability. It is constant on time pulse width

modulation (PWM) controller that supports FCOT

mode control. Operation frequency depends on Input

and output voltage condition.

The FR9811 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 FR9811 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 FR9811 is offered in SOT-23-6 package, which

provides good thermal conductance.

Low RDS(ON) Integrated Power MOSFET

(145mΩ/90mΩ)

l Wide Input Voltage Range: 4.5V to 23V

l Output Voltage Range: 0.6V to 8V

l 2A Output Current

l FCOT Mode Enables Fast Transient Response

l Pseudo 850kHz Frequency

l Input Under Voltage Lockout

l Internal 1.5ms Soft-Start

l Cycle-by-Cycle Current Limit

l Hiccup Short Circuit Protection

l Over Temperature Protection with Auto Recovery

l SOT-23-6 Package

Applications

l STB (Set-Top-Box)

l LCD Display, TV

l Distributed Power System

l Networking, XDSL Modem