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FN6408.1

July 11, 2007

The HSx switches can also pass USB full-speed signals

(12Mbps) with minimal distortion and meet all the USB

requirements for USB 2.0 full-speed signaling. See Figure 11.

The maximum signal range for the HSx switches is from

than -1.5V.

The HSx switches are active (turned ON) whenever the IN

operated with a 2.7V to 3.6V supply.

ISL54200 Operation

The discussion that follows will discuss using the ISL54200 in

the typical application shown in the“Application Block

Diagram” on page 8.

POWER

The power supply connected at the VDD (pin 1) provides the

DC bias voltage required by the ISL54200 part for proper

operation. The ISL54200 can be operated with a VDD

voltage in the range of 2.7V to 5.5V. When used in a USB

application, the VDD voltage should be kept in the range of

3.0V to 5.5V to ensure you get the proper signal levels for

good signal quality.

A 0.01µF or 0.1µF decoupling capacitor should be

connected from the VDD pin to ground to filter out any power

supply noise from entering the part. The capacitor should be

located as close to the VDD pin as possible.

LOGIC CONTROL

The state of the ISL54200 device is determined by the

voltage at the IN pin (pin 2) and the EN pin (pin 10). IN is

only active when the EN pin is logic “1” (High). Refer to the

“Truth Table” on page 2.

The EN pin is internally pulled low through a 4M

Ω resistor to

ground. For logic “0” (Low) it can be driven low or allowed to

Float. The IN pin must be driven low or high and cannot be

left floating.

Logic control voltage levels:

Full-speed Mode

If the IN pin = Logic “0” and the EN pin = Logic “1”, the part

will be in the full-speed mode. In this mode, the FSD1 and

FSD2 switches are ON and the HSD1 and HSD2 switches

be in the range of 2.8V to 3.6V and will be connected to the

battery or LDO of the portable media device. When a

computer or USB hub is plugged into the common USB

connector and the part is in the full-speed mode, a link will

be established between the full-speed driver section of the

media player and the computer. The device will be able to

transmit and receive data from the computer at a data rate of

12Mbps.

High-speed Mode

If the IN pin = Logic “1” and the EN pin = Logic “1”, the part

will go into high-speed mode. In high-speed mode, the

HSD1 and HSD2 switches are ON and the FSD1 and FSD2

switches are OFF (high impedance). When a USB cable

from a computer or USB hub is connected at the common

USB connector and the part is in the high-speed mode, a link

will be established between the high-speed driver section of

the media player and the computer. The device will be able

to transmit and receive data from the computer at a data rate

of 480Mbps.

All Switches OFF Mode

If the IN pin = Logic “0” or Logic “1” and the EN pin = Logic “0”,

all of the switches will turn OFF (high impedance).

The all OFF state can be used to switch between the two

USB sections of the media player. When disconnecting from

one USB device to the other USB device, you can

momentarily put the ISL54200 switch in the “all off” state in

order to get the computer to disconnect from the one device

so it can properly connect to the other USB device when that

channel is turned ON.

ISL54200