isl54214 Intersil Corporation, isl54214 Datasheet - Page 10

• Manufacturer Part Number: isl54214
• Description: Usb 2.0 High-speed X 2channels/stereo Audio Dual Sp3t Dual 3 To 1 Multiplexer
• Manufacturer: Intersil Corporation

high-speed USB differential data signals in the range of 0V
to 400mV. The switches have low capacitance and high
bandwidth to pass USB high-speed signals (480Mbps) with
minimum edge and phase distortion to meet USB 2.0 signal
quality specifications. See Figures 24 and 25 for High-speed
Eye Pattern taken with switch in the signal path.
These switches can also swing rail to rail and pass USB
full-speed signals (12Mbps) with minimal distortion. See
Figure 26 for Full-speed Eye Pattern taken with switch in the
signal path.
The maximum normal operating signal range for the USB
switches is from -1V to V
should not be allow to exceed the V
below ground by more than -1V for normal operation.
However in the event that the USB 5.25V V
shorted to one or both of the COM pins, the ISL54214 has
special fault protection circuitry to prevent damage to the
ISL54214 part. The fault circuitry allows the signal pins
(COM-, COM+, 1D-, 1D+, 2D-, 2D+, L and R) to be driven up
to 5.5V while the V
4.6V. In this condition the part draws < 1
causes no stress to the IC. In addition when V
(ground) all switches are OFF and the fault voltage is
isolated from the other side of the switch. When V
range of 2.7V to 4.6V the fault voltage will pass through to
the output of an active switch channel. Note: During the fault
condition normal operation is not guaranteed until the fault
condition is removed.
The USB (1D+ and 1D-) switches are active (turned ON)
whenever the C1 is logic “0” (Low) and C0 is logic “1” (High).
The USB (2D+ and 2D-) switches are active (turned ON)
whenever the C1 is logic “1” (High) and C0 is logic “0” (Low)
provided the last state was not the Audio or Audio Mute
state.
ISL54214 Operation
The discussion that follows will discuss using the ISL54214 in
the “Application Block Diagrams” on page 9.
LOGIC CONTROL
The state of the ISL54214 device is determined by the
voltage at the C1 pin (pin 9) and the C0 pin (pin 10). The part
has five states or modes of operation. The All SWITCHES
OFF mode, USB1 mode, USB2 mode, Audio mode and
Audio Mute mode. Refer to the “Truth Table” on page 3 and
“State Diagram” on page 2.
The C1 pin and C0 pin are internally pulled low through 4M
resistors to ground and can be tri-stated or left floating.
Logic Control Voltage Levels
With VDD in the range of 2.7V to 3.6V the logic levels are:
C1, C0 = Logic “0” (Low) when
C1, C0 = Logic “1” (High) when
DD
supply voltage is in the range of 0V to
DD
. The signal voltage at D- and D+
10
≤
≥
0.5V or Floating.
1.4V
DD
voltage rail or go
μ
A of current and
BUS
DD
voltage were
DD
is at 0V
is in the
ISL54214
Ω
ALL SWITCHES OFF Mode
If the C1 pin = Logic “0” and C0 pin = Logic “0” the part will
be in the ALL SWITCHES OFF mode. In this mode the 2D-
and 2D+ USB switches, the L and R audio switches and the
1D- and 1D+ USB switches will be OFF (high impedance).
The 1kΩ shunts on the COM side will be disconnected
(OFF).
It is recommended that when transitioning from USB1 to
USB2 or from USB2 to USB1 that you always pass through
the All Switches OFF state.
Audio Mode
If the C1 pin = Logic “1” and C0 pin = Logic “1” the part will
be in the Audio mode. In Audio mode the L (left) and R (right)
2.3Ω audio switches are ON, the 1D- and 1D+ 6.2Ω USB
switches and 2D- and 2D+ 6.2Ω USB switches will be OFF
(high impedance).
The 1kΩ shunts on the COM side of the switch will be
disconnected (OFF).
When a headphone is plugged into the common connector,
the µcontroller will drive the C1 and C0 logic pins “High”
putting the part in the audio mode. In the audio mode, the
audio drivers of the player can drive the headphones and
play music.
USB1 Mode
If the C1 pin = Logic “0” and C0 pin = Logic “1” the part will
go into USB1 mode. In USB1 mode the 1D- and 1D+ 6.2Ω
switches are ON and the L and R 2.3Ω audio switches and
2D- and 2D+ 6.2Ω USB switches will be OFF (high
impedance).
The 1kΩ COM shunt resistors will be disconnected (OFF).
When a USB cable from a computer or USB hub is
connected at the common connector, the μcontroller will
route the incoming USB signal to USB transceiver section #1
by taking the C1 pin “Low” and the C0 pin “High” putting the
ISL54214 part into the USB1 mode. In USB1 mode the
computer or USB hub transceiver and the MP3 player or
cellphone USB transceiver #1 are connected and digital data
will be able to be transmit back and forth.
USB2 Mode
If the C1 = Logic “1” and C0 pin = Logic “0” the part will be in
the USB2 mode provided that the last state was not the
Audio or Audio Mute state. In the USB2 mode the 2D- and
2D+ 6.2Ω USB switches will be ON and audio switches and
the 1D- and 1D+ USB switches will be OFF (high
impedance).
The 1kΩ COM shunt resistors will be disconnected (OFF).
When a USB cable from a computer or USB hub is
connected at the common connector, the μcontroller will
route the incoming USB signal to USB transceiver section #2
December 11, 2008
FN6816.0