an1359

ISL54208EVAL1Z Evaluation Board User’s
Manual
®
Application Note
Description
June 23, 2008
AN1359.0
Picture of Evaluation Board (Top View)
The ISL54208EVAL1Z evaluation board is designed to
provide a quick and easy method for evaluating the
ISL54208 USB/CVBS/Audio IC.
The ISL54208 device is an unique IC. To use this evaluation
board properly, requires a thorough knowledge of the
operation of the IC. Refer to the ISL54208 datasheet for an
understanding of the functions and features of the device.
Studying the device’s truth table along with its pinout
diagram on page 2 of the ISL54208 datasheet, is the best
way to get a quick understanding of how the part works.
A picture of the main evaluation board is shown in Figure 1.
The ISL54208 µTQFN IC is soldered onto the evaluation
board. It is located in the center of the board and is
designated as U1.
The ISL54208 IC is a dual SPDT analog switch that has two
modes of operation: Audio/Video mode and USB mode. The
evaluation board contains standard RCA, BNC, and USB
connectors to allow the user to easily interface with the IC to
evaluate its functions, features, and performance in these
two modes of operation.
For example, when the board is properly powered, the
video/mono audio outputs of a video MP3 player can be
connected at RCA connectors J13 (VIDEO IN) and J15
(MONO AUDIO IN) and the USB output of the player can be
connected at the USB connector J12 (USB TO DEVICE) on
the board. See Figure 2 on page 4. A TV can be connected
at RCA jacks J5 (VIDEO OUT) and J7 (MONO AUDIO OUT)
to play the video on the TV. You can then turn-off the video,
disconnected the TV, and attach a USB cable from a
computer to USB connector J4 (USB TO HOST) to load
digital video tracks into the player.
This application note will guide the user through the process
of configuring and using the evaluation board to evaluate the
ISL54208 device in both the Audio/Video mode and the USB
mode.
Key Features
• Standard USB Connectors
• RCA Audio/Video Input Jacks and BNC Connectors
• Convenient Test Points and Connections for Test
Equipment
• VBUS from USB Host Logic Drive Capability
1
FIGURE 1. ISL54208EVAL1Z EVALUATION BOARD
Board Architecture/Layout
Basic Layout of Evaluation Board
The basic layout of the main board is as follows: Refer to
Figure 1.
Power (J2), GND (J1), logic IN (J3) and logic CTRL (J11)
banana jack connections are at the top of the board.
Audio/Video Source RCA inputs are at the lower right side of
the board (J13 and J15). Audio/Video RCA outputs are at
the lower left side of the board (J5 and J7).
A standard “B” type USB connection to an upstream host
controller (Computer) is made at connector J4, located on
left underside of the board. A standard “A” type USB
connection to a downstream USB device is made at
connector J12, located on right underside of the board.
Located in the center of the board is the ISL54208 IC (U1).
The evaluation board has a pin 1 dot, to show how the IC
should be oriented on to the evaluation board. The IC pin 1
indicator dot needs to be aligned with the evaluation board
pin 1 dot indicator.
Note: The connectors J5 (VIDEO OUT) and J7 (MONO
AUDIO OUT) are connected in parallel to J4 (USB TO
HOST). When driving the USB input, the A/V output should
be in a high impedance state (and vice versa).
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2008. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
Application Note 1359
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
100µA of current.
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 VBUS line if jumper
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 VBUS of the USB computer. See the
“Modifying The EVAL Board TO USE the Computer VBUS
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 VBUS VOLTAGE TO DRIVE THE “IN’ PIN
Rather than using a logic controller to control the IN logic
pin, you can directly drive the IN pin using the VBUS voltage
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 VBUS
connection of the USB connector at J4.
2
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 VDD voltage
by as much as 2.55V. This allows the VBUS voltage from a
computer or USB hub (4.4V to 5.25V) to drive the IN pin
while the VDD voltage is in the range of 2.7V to 3.6V.
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 (0.707VRMS) these switches
have an extremely low rON resistance variation (0.03Ω).
They can pass ground referenced audio/video signals up to
0.707VRMS with very low distortion and degradation. A
3VP-P signal is acceptable but performance will degrade.
The audio/video channels are AC-coupled with 100µF
capacitors (C3 and C4). These capacitors remove any DC
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
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June 23, 2008
Application Note 1359
connected to VIDEO OUT (J5) and the audio input port of
the TV should be connected to MONO AUDIO OUT (J7).
populated with 0Ω resistors. R1 and R2 are located between
the J9 and J10 BNC connectors.
The BNC connector J6 is in parallel with J5 and the D- line of
the J4 (USB TO HOST) connector. The BNC connector J8 is
in parallel with J7 and the D+ line of the J4 (USB TO HOST)
connector. These BNC connectors can be used to connect
resistive loads and/or test equipment to evaluate the
performance of the IC.
Note: Before connecting the USB host controller at
connector J4, the A/V connections must be disconnected (or
set to high impedance) from the VIDEO OUT and MONO
AUDIO OUT connectors (J5-J8). This will prevent the
audio/video load from interfering with USB signal
transmission.
Note: When in USB mode, devices on the audio/video
outputs need to be in a high impedance state so it will not
interfere with the USB signal, since the USB and A/V
connections on the output/upstream side are all wired in
parallel.
Application
USB Connections
A “B” type USB receptacle labeled “USB TO HOST” (J4) is
located on the left underside of the board. This receptacle
should be connected, using a standard USB cable, to the
up-stream USB host controller which is usually a PC
computer or hub. When this connection is made and the IN
logic control is driven HIGH, the ISL54208 device will go into
USB mode. High Speed USB signals can be passed
between J4 and J12.
An “A” type USB receptacle labeled USB TO DEVICE (J12)
is located on the right underside of the board. The USB
device can be plugged directly into this receptacle or through
a standard USB cable.
In USB mode the USB host controller and USB device will
be connected through the internal NO switches of the IC.
The NO switches are bi-directional which allow the host
(computer) and downstream USB device to both send and
receive data.
JP1 and JP2 permit the connection of differential probes for
monitoring of the USB signals. JP1 is used for monitoring on
the device side. JP2 is used for monitoring on the host side.
In addition, BNC connectors J9 (D-) and J10 (D+) can be
connected in parallel to J12 for monitoring the USB signals
on the device side using an oscilloscope. Normally, J9 and
J10 are not connected to the USB signal path. If the user
requires BNC connections to the USB signals on the device
side, then R1 and R2 on the evaluation board can be
3
The main purpose of the ISL54208 device is to allow the use
of a common USB and Audio/Video Connector in Personal
Media Players and other portable battery powered
equipment. Either a TV monitor will be in the common
connector to play video or a USB cable from a computer will
be in the common connector to transmit digital data, such as
music videos or MP3 songs into the memory of the Media
Player.
Board Component Definitions
DESIGNATOR
DESCRIPTION
U1
ISL54208IRUZ IC
J1
Ground Connection
J2
VDD Positive Connection
J3
IN Logic Input
J4
“B” type USB Receptacle
J5, J6
VIDEO OUT Outputs
J7, J8
MONO AUDIO OUT Outputs
J9
USB (D-) BNC Connector
J10
USB (D+) BNC Connector
J11
CTRL Logic Input
J12
“A” type USB Receptacle
J13, J14
VIDEO IN Inputs
J15, J16
MONO AUDIO IN Inputs
JP1, JP2
D-/D+ Differential Probe Connection
JP3
VBUS Logic Control Connection
JP4
4.3MΩ Pull-Down Disconnect
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June 23, 2008
Application Note 1359
+
DC POWER
SUPPLY
+3.3V
VIDEO MP3 PLAYER
VIDEO
DRIVER
COMPUTER
USB PORT
IN
VDD
J2
J3
J1
JP4
USB TO HOST
USB PORT
CTRL
GND
AUDIO
DRIVER
J11
J9
USB
TO
DEVICE
JP3
J4
J2
JP2
U1
JP1
J10
TV MONITOR
VIDEO IN
VIDEO OUT
C3
AV VIDEO
J5
J6
AV AUDIO
J7
J8
COMPOSITE VIDEO
J14
J13
J16
J15
C4
MONO AUDIO OUT
MONO AUDIO IN
MONO AUDIO
ISL54208 EVALUATION BOARD
FIGURE 2. BASIC EVALUATION TEST SETUP BLOCK DIAGRAM
Using The Board (Refer to Figure 2)
Lab Equipment
The equipment, external supplies and signal sources
needed to operate the board are listed as follows:
1. +3V to 5V DC Power Supply
2. Audio/Video Media Player with USB connector (video
MP3, digital camera, camcorder) or Audio/Video
Generator
3. TV Monitor or Audio/Video Analyzer/Oscilloscope
4. Two standard USB cables
5. Computer with USB port
Initial Board Setup Procedure
1. Attach the main evaluation board to the DC power supply
at J2 (VDD) and J1 (GND). Positive terminal at J2 and
negative terminal at J1. The supply should be capable of
delivering 3V to 5V and 100µA of current. Set the supply
voltage to 3.3V.
2. Connect the media player’s composite video source to
the J13 RCA connector or the J14 BNC connector and
the mono audio source to the J15 RCA connector or J16
BNC connector. Set the media player to output either
NTSC or PAL composite video signal.
3. Connect the USB port of the media player to the USB “A”
type receptacle, J12 (USB TO DEVICE).
Audio/Video Mode Operation
1. Connect the TV monitor AV video input at J5 (VIDEO
OUT) and the AV audio input at J7 (MONO AUDIO OUT).
No USB cable should be connected at the J4 (USB TO
HOST) connector.
2. Set the TV to receive the video signal through its AV input
and set to the appropriate channel.
3. Connect J3 (IN) to J1 (GND) or leave floating if JP4 is
connected. Connect J11 (CTRL) to J2 (VDD). You will
now be in Audio/Video mode (3Ω NC switches are ON).
4. Turn the audio/video media player ON. You should hear
and see the video on the TV screen.
5. You can observe the audio/video signals at the output of
the IC on an oscilloscope or audio/video analyzer by
using the J6 and J8 BNC connectors or appropriate test
points.
USB Mode Operation
1. Turn OFF the audio/video from the media player.
2. Disconnect the TV monitor from J5 and J7 RCA or J6 and
J8 BNC connectors.
3. Connect J3 (IN) to J2 (VDD) or leave floating if JP3 is
connected to pins 1 and 2.
4. Connect a USB cable from host (PC computer) to the
USB “B” type receptacle, J4 (USB TO HOST). You will
now be in USB mode (5Ω NO switches are ON).
5. You should now be able to send and receive data
between the host and USB device.
4
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Application Note 1359
Test Points
6. You can observe the D- and D+ USB signals on an
oscilloscope or other test equipment by connecting to the
J6 and J8 BNC connectors. Connect to J6 for D- signal
and to J8 for D+ signal.
The board has various test points for ease of connecting
probes to make measurements. The test points available are
described in Table 1.
7. Remove the 0Ω resistors R3 and R4 when evaluating the
performance (i.e. eye diagram, etc.) of the high speed
USB signal. Removal of these resistors disconnects the
RCA connectors (J5 and J7) and the BNC connectors (J6
and J8) from the USB differential lines. These
components when connected will degrade the USB
signal. These components will not be there in an actual
application. Note: R3 and R4 are located on the
underside of the board.
TABLE 1. TEST POINTS DESCRIPTIONS
DESIGNATOR
If you disconnect the USB cable from J4 and take the IN pin
LOW, the IC will return to Audio mode. You can now plug the
TV monitor into J5 and J7, turn the audio/video of the player
ON to once again play the music video or movie.
DESCRIPTION
TP1
VDD Test Point
TP2
Ground Test Point
TP3
VBUS Test Point
TP4
VIDEO IN Test Point
TP5
MONO AUDIO IN Test Point
JP1
D-/D+ Differential Probe Connection - USB Device
Side of Switch
JP2
D-/D+ Differential Probe Connection - HOST Side
of Switch
Board Schematic
D1
J9
2 3 4 5
A
VDD
GND
D+
J1
C1
VDD
10UF
C2
C5
J11
R7
1
R6
2
1
R1
2
10
5
1
3
J4
COM2
1
JP2
3
4
4
10 PIN
PACKAGE
46
2
6
R3
MOUNT
0
1
0
R4
4
1
3
9
9
8
8
7
7
2
3
D+
4
6
JP1
DIFF
PROBE
ADAPTER
6
1
2
3
DIFF
PROBE
ADAPTER
4
MOUNT
J12
A
1
A
2
A
A
A
USB
TO
DEVICE
4
J13
3
USB
COM1
MOUNT
1
D-
U1
QFN
5
2
1
2
5
2
3
4
897-43-004-90-000
3
1
2
5
USB TYPE A
2 3 4
MOUNT
USB
TO
HOST
DNP
0
1
JP3
DNP
R2
2
4.3M
A
CTRL
1
0
10
1
2
3
JP4
2
OPEN
1
1
R5
A
1
A
0.1UF
IN
1
J10
2 3 4 5
1
1
TP1
J3
TP2
1
TP10
1
TP3
1
J2
TP4
VIDEO IN
A
1
J5 4
2
1
3
C3
VIDEO OUT
TP5
A
J6
1
100UF
A
1
C4
1
2
5 4 3
J14
2 3 4 5
1
100UF
2
J15
3 4
MONORIGHT
AUDIO IN
A
A
J7
4 3
1
1
2
2
J16
3 4 5
MONO AUDIO OUT
A
J8
A
1
2
5 4 3
A
Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to
verify that the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
5
AN1359.0
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