ISL54208EVAL1Z Intersil, ISL54208EVAL1Z Datasheet - Page 2

• Manufacturer Part Number: ISL54208EVAL1Z
• Description: EVALUATION BOARD FOR ISL54208
• Manufacturer: Intersil

Specifications of ISL54208EVAL1Z

• Main Purpose: Interface, Analog & Digital Switch
• Embedded: No
• Utilized Ic / Part: ISL54208
• Primary Attributes: 2 x SPDT Audio, USB & Video Switch
• Secondary Attributes: 1.8 V ~ 5.5 V Supply
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Power Supply
The DC power supply connected at banana jacks J2 (VDD)
and J1 (GND) provides power to the evaluation board. The
IC requires a +2.7V to +3.6V DC power supply for proper
operation. The power supply should be capable of delivering
100µ
Logic Control
The state of the ISL54208 device is determined by the
voltage at the IN pin and the CTRL pin. Access to the CTRL
pin is through the banana jack J11 (CTRL) and access to the
IN pin is through the banana jack J3 (IN) if jumper JP3 is in
the 2 to 3 position and through the J4 V
JP3 is in the 1 to 2 position.
The following control pins are 1.8V logic compatible which
allows for control via a standard µcontroller.
IN = Logic “0” (LOW) when <= 0.5V
IN = Logic “1” (HIGH) when >= 1.4V
CTRL = Logic “0” (LOW) when <= 0.5V or Floating
CTRL = Logic “1” (HIGH) when >= 1.4V
Note: The ISL54208 on the CTRL pin has an internal 4MΩ
pull down resistor while the IN pin has no internal pull-down.
The evaluation board has a external 4.3MΩ pull-down
resistor from the IN pin to ground. This pull-down is required
if you want to configure the evaluation board to control the
ISL54208 device via the V
“Modifying The EVAL Board TO USE the Computer V
Voltage To Drive the “IN” Pin” in following section. You can
disconnect this external resistor by simply removing jumper
JP4 on the evaluation board.
If IN is driven LOW and CTRL is HIGH the part will be in the
Audio/Video mode. The NC switches will be ON and the NO
switches will be OFF. There will be a low impedance path
from VIDEO IN to VIDEO OUT and from MONO AUDIO IN to
MONO AUDIO OUT.
If IN is driven HIGH and CTRL = X (don’t care) the part will
be in the USB mode. The NO switches will be ON and the
NC switches will be OFF. There will be a low impedance path
from USB TO DEVICE to USB TO HOST.
If IN = LOW and CTRL = LOW the part will be in the Low
Power mode. In Low Power mode all switches are OPEN
and the IC will draw around 1nA of current.
MODIFYING THE EVAL BOARD TO USE THE
COMPUTER V
Rather than using a logic controller to control the IN logic
pin, you can directly drive the IN pin using the V
from the computer. Jumper JP3 enables this function. When
JP3 is connected on pins 2 and 3, logic control to the IN pin
is through the banana jack J3. When JP3 is connected on
pins 1 and 2, logic control to the IN pin is through the V
connection of the USB connector at J4.
A
of current.
BUS
VOLTAGE TO DRIVE THE “IN’ PIN
BUS
2
of the USB computer. See the
BUS
line if jumper
BUS
Application Note 1359
voltage
BUS
BUS
When the USB connector at J4 is not connected to a USB
port on a computer, the 4.3MΩ pull-down will pull the IN pin
low putting the ISL54208 in the Audio/Video mode or Low
Power mode depending on the condition of the CTRL pin.
When a connection to a computer USB host is present on
J4, the voltage at the IN pin will be driven to 5V and the part
will automatically go into the USB mode.
Note: The voltage at the IN pin can exceed the V
by as much as 2.55V. This allows the V
computer or USB hub (4.4V to 5.25V) to drive the IN pin
while the V
Audio/Video Inputs
The evaluation board has two audio/video inputs labeled
VIDEO IN (J13) and MONO AUDIO IN (J15). Each of these
inputs have a BNC connector (J14 and J16 respectively)
wired in parallel with the RCA connector. You can connect an
audio/video source or generator at either the BNC connector
or the RCA connector.
In a typical application the composite video output (NTSC or
PAL) and the mono audio output of the video source, (i.e.
TV, video MP3 Player, digital camera, cellphone, etc.), would
be connected to the RCA jacks J13 for video and J15 for
mono audio on the evaluation board.
Over a signal range of ±1V (0.707V
have an extremely low r
They can pass ground referenced audio/video signals up to
0.707V
3V
The audio/video channels are AC-coupled with 100µF
capacitors (C
voltage from the audio/video signals and reference them to
ground of the device. If the audio/video source being
connected to the evaluation board already has internal
AC-coupling capacitors at the output of its drivers then the
capacitors on the evaluation board should be shorted out
(replaced with 0Ω resistors). This will prevent further
attenuation of the low frequency content of the audio signal
due to the increase of the high-pass corner frequency
resulting from the evaluation board capacitor in series with
the audio/video source capacitor.
Note: When in USB mode the audio/video source needs to
be in a high impedance state so it will not interfere with the
USB signal. Since the audio/video source inputs are
AC-coupled on the evaluation board, simply turning the
audio/video source OFF will isolate it from interfering with
the USB signal.
Audio/Video Outputs
The evaluation board has RCA type connectors labeled J5
and J7 for A/V output connections. For video playback, a TV
monitor should be connected at these connectors using a
standard A/V cable. The video input port of the TV should be
P-P
signal is acceptable but performance will degrade.
RMS
DD
with very low distortion and degradation. A
3
voltage is in the range of 2.7V to 3.6V.
and C
4
). These capacitors remove any DC
ON
resistance variation (0.03Ω
RMS
BUS
) these switches
voltage from a
DD
June 23, 2008
voltage
AN1359.0
)
.