APPLICATION INFORMATION

The FC6261 Series is current-limited,power distribu�on switches using P-channel MOSFETs.Addi�onal device

shutdown features include over temperature protec�on and reverse-voltage protec�on. The driver controls

the gate voltage of the power switch. The driver incorporates circuitry that controls the rise and fall �mes of

the output voltage to limit large current and voltage surges and provides built-in so�-start func�onality. The

FC6261 Series enters constant current mode when the load exceeds the current-limit threshold.

Input and Output

IN (input) is the power supply connec�on to the logic circuitry and the drain of the output MOSFET. OUT

(output) is the source of the output MOSFET. In a typical applica�on, current flows through the switch from

IN to OUT toward the load. OUT pin must be connected together to the load.

So� Start for Hot Plug-In Applica�ons

In order to eliminate the upstream voltage droop caused by the large inrush current during hot-plug events,

the “so�-start” feature effec�vely isolates the power source from extremely large capaci�ve loads, sa�sfying

the USB voltage droop requirements.

FLG Func�on

The nFLG open-drain output is asserted (ac�ve low) when an over current condi�on is encountered a�er a

8ms deglitch �meout. The nFLG output remains asserted un�l the over-current condi�on is removed. Over

temperature condi�on is also reported by nFLG open-drain output. In addi�on, nFLG is also asserted (ac�ve

low) in output reverse-voltage condi�on when the output reverse-voltage condi�on is removed.

Thermal Shutdown

The FC6261 Series has internal over temperature protec�on to shut down the device when its

junc�on temperature exceeds 150°C with over load current condi�on, then a�er the device is disabled,

if the junc�on temperature drops 20°C hysteresis typically the device will resume and restart to work.

The switch con�nues to cycle off and on un�l the over current fault is removed.

EN, the Enable Input

EN must be driven logic high or logic low for a clearly defined input. Floa�ng the input may cause

unpredictable opera�on, so please do not float EN input pin.

Output Auto Discharge

Only for FC6261B1, when its EN is disabled, an internal typical 42Ω resister is connected between OUT and

Layout Considera�on

For best performance of the FC6261 Series, the following guidelines must be strictly followed.

1) Input and output capacitors should be placed close to the IC and connected to ground plane to reduce

noise coupling.

2) The GND should be connected to a strong ground plane for heat sink.

FC6261

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3)

Keep the main current traces as possible as short and wide.