8

Reverse current preventing

The output MOSFET and driver circuitry are also designed to allow the MOSFET source to be externally

H

will automatically shut off the MOSFET.

Layout and Thermal Dissipation

1. Place the switch as close to the USB connector as possible. Keep all traces as short as possible to

reduce the effect of undesirable parasitic Inductance.

2. Place the output capacitor and ferrite beads as close to the USB connector as possible. If ferrite beads

are used, use wires with minimum resistance and large solder pads to minimize connection resistance.

3. If ferrite beads are used, use wires with minimum resistance and large solder pads to minimize

connection resistance.

4. If the package is with dual VOUT or VIN pins, short both the same function pins to reduce the internal

turn-on resistance. If the output power will be delivered to two individual ports, it is especially necessary

to short both VOUT pin at the switch output side in order to protect the switch when each port is plug-in

separately.

5. Under normal operating conditions, the package can dissipate the channel heat away. Wide power

bus planes connected to VIN and VOUT and a ground plane in contact with the device will help

dissipate additional heat.

HM9708