3
AN1408.0
February 13, 2009
the D+ line of the J1 (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.
USB Connections
A “B” type USB receptacle labeled “USB TO HOST” (J1) is
located on the left under-side 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 ISL54211 device will go into
USB mode. The USB switches will be turned ON.
An “A” type USB receptacle labeled USB TO DEVICE (J2) is
located on the right under-side 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 USB switches of the IC.
The USB switches are bi-directional which allow the host
(computer) and downstream USB device to both send and
receive data.
Note: Before connecting the USB host controller at
connector J1, the headphones must be removed from the
headphone speaker jack, J7. This will prevent the audio load
from interfering with USB signal transmission.
The main purpose of the ISL54211 device is to allow the use
of a common USB and Audio Headphone Connector in
Personal Media Players and other portable battery powered
equipment. Either a headphone will be in the common
connector to play music or a USB cable from a computer will
be in the common connector to transmit digital data, such as
music, into the memory of the media player.
The BNC connector J8 (COM-) is in parallel with the D- line
of the J1 USB connector. The BNC connector J9 (COM+) is
in parallel with the D+ line of the J1 USB connector.
The BNC connector J14 (D-) is in parallel with the D- line of
the J2 USB connector. The BNC connector J15 (D+) is in
parallel with the D+ line of the J2 USB connector. If you want
to use the J14 and J15 BNC connectors you must populate
R1 and R2 with 0
Ω
resistors. These BNC connectors can be
used to connect test equipment to evaluate the performance
of the IC.
Board Component Definitions
TABLE 1. BOARD COMPONENT DEFINITIONS
DESIGNATOR
DESCRIPTION
U1
ISL54211IRUZ IC
J1
“B” type USB Receptacle
J2
“A” type USB Receptacle
J3, J5
Left Stereo Audio Input
J4, J6
Right Stereo Audio Input
J7
Headphone Speaker Jack
J8
COM- BNC Connector
J9
COM+ BNC Connector
J10
VDD Positive Connection
J11
VDD Negative Connection
J12
CTRL Logic Control
J13
IN Logic Control
J14
D- BNC Connector
J15
D+ BNC Connector
JP1, JP2
D-/D+ Differential Probe Connection
JP3
IN Pin Connector Selection
Jumper Position 2 - 3 Control through J13
Jumper Position 2 - 1 Control through J1
JP4
Connect 4M
Ω
Pull-down Resistor to IN Pin
Not required for the ISL54211 part.
Application Note 1408
