ISL54222IRUZ-T INTERSIL [Intersil Corporation], ISL54222IRUZ-T Datasheet - Page 8

• Manufacturer Part Number: ISL54222IRUZ-T
• Description: High-Speed USB 2.0 (480Mbps) Multiplexer
• Manufacturer: INTERSIL [Intersil Corporation]

range of 1.8V to 3.3V the fault voltage will pass through to
the output of an active switch channel. During the fault
condition normal operation is not guaranteed until the fault is
removed. See the “USB 2.0 V
section below.
The HS1 channel switches are active (turned ON) whenever
the SEL voltage is Logic ”0” (Low) and the OE voltage is
Logic ”0”(Low).
The HS2 channel switches are active (turned ON) whenever
the SEL voltage is Logic “1” (High) and the OE voltage is
Logic “0” (Low).
ISL54222 Operation
The following will discuss using the ISL54222 shown in the
“Application Block Diagram” on page 7.
POWER
The power supply connected at the V
bias voltage required by the ISL54222 part for proper
operation. The ISL54222 can be operated with a V
voltage in the range of 1.8V to 3.3V.
A 0.01µF or 0.1µF decoupling capacitor should be
connected from the V
supply noise from entering the part. The capacitor should be
located as close to the V
LOGIC CONTROL
The state of the ISL54222 device is determined by the
voltage at the SEL pin and the OE pin. SEL is only active
when the OE pin is Logic “0” (Low). Refer to the “Truth Table”
on page 2.
The ISL54222 logic pins are designed to minimize current
consumption when the logic control voltage is lower than the
V
the part typically draws only 35µA of I
V
only 6µA of I
supply rail minimizes power consumption.
The logic pins must be held High or Low and must not float.
Logic Control Voltage Levels
With V
logic levels are:
OE = Logic “0” (Low) when V
OE = Logic “1” (High) when V
SEL = Logic “0” (Low) when V
SEL = Logic “1” (High) when V
HSD1 USB Channel
If the SEL pin = Logic “0” and the OE pin = Logic “0”,
high-speed Channel 1 will be ON. The HSD1- and HSD1+
switches are ON and the HSD2- and HSD2+ switches are
OFF (high impedance).
DD
DD
supply voltage. With V
= 1.8V and logic pins at 1.4V the part typically draws
DD
supply voltage in the range of 1.8V to 3.3V the
DD
current. Driving the logic pins to the V
DD
DD
pin to ground to filter out any power
DD
pin as possible.
OE ≤
OE ≥
BUS
8
SEL ≤
SEL ≥
= 3.3V and logic pins at 1.4V
0.5V
Short Requirements”
1.4V
0.5V
1.4V
DD
DD
pin provides the DC
current. With
DD
DD
ISL54222
When a computer or USB hub is plugged into the common
USB connector and Channel 1 is active, a link will be
established between the USB 1 transceiver section of the
media player and the computer. The device will be able to
transmit and receive data from the computer.
HSD2 USB Channel
If the SEL pin = Logic “1” and the OE pin = Logic “0”,
high-speed Channel 2 will be ON. The HSD2- and HSD2+
switches are ON and the HSD1- and HSD1+ switches are
OFF (high impedance).
When a USB cable from a computer or USB hub is
connected at the common USB connector and Channel 2 is
active, a link will be established between the USB 2
transceiver section of the media player and the computer.
The device will be able to transmit and receive data from the
computer.
All Switches OFF Mode
If the SEL pin = Logic “0” or Logic “1” and the OE pin =
Logic “1”, 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 switching from one
USB transceiver section to the other USB transceiver
section, you can momentarily put the ISL54222 switch in the
“ALL OFF” state, in order to get the computer to disconnect
from the current USB section, so it can properly connect to
the other USB transceiver section when that channel is
turned ON.
USB 2.0 V
The USB 2.0 specification in chapter 7, section 7.1.1 states
a USB device must be able to withstand a V
D+ or D- signal lines when the device is either powered off or
powered on for at least 24 hours. The ISL54222 part has
special fault protection circuitry to meet these short circuit
requirements.
The fault protection circuitry allows the signal pins (D-, D+,
HSD1-, HSD1+, HSD2-, HSD2+) to be driven up to 5.5V
while the V
this overvoltage condition the part draws < 300µA of I
current and causes no stress/damage to the IC.
In addition when V
and the shorted V
of the switch.
When V
voltage will pass through to the output of an active (turned
ON) switch channel but not through a turned OFF channel.
Any components connected on the active channel must be
able to withstand the overvoltage condition.
Note: During the fault condition normal operation of the USB
channel is not guaranteed until the fault condition is
removed.
DD
DD
is in the range of 1.8V to 3.3V, the shorted V
BUS
supply voltage is in the range of 0V to 3.3V. In
Short Requirements
BUS
DD
is at 0V (ground), all switches are OFF
voltage is isolated from the other side
BUS
February 9, 2009
short to the
DD
FN6835.0
BUS