USB Multimedia Switches0 pages

USB MULTIMEDIA SWITCHES

USB AND AUDIO SWITCHING FOR MOBILE APPLICATIONS
Fairchild’s Offering
Fairchild’s multimedia switches are ideal for sharing a single USB port or connector with audio, data and video
applications. They can also be used for isolation and multiplexing of USB and audio signals.
The switches are designed to be compliant with USB2.0 full-speed (FS) and high-speed (HS) standards with
bandwidths in excess of 720Mhz.

Eye Diagram: FSA800

Broadband
Processor

Differential Signal (V)

0.5

FSA800

VCC

mini/micro
USB

MIC HOST

0.4

Audio
Codec

0.3
0.2

UART or
FS USB

0.1
0.0

HS USB

-0.1

R HOST
L HOST
RxD_HOST
TxD_HOST
DP_HOST
DM_HOST

SEL [0]
SEL [1]
SEL [2]

-0.2
-0.3

R

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Time (x10-9)s
Built-in Termination
Resistor
The built-in termination resistors allow for
switching between multiple outputs by
terminating unselected ports to ground.
This method effectively removes any charge
present from parasitic sources before switching
to the selected output and thus prevents
audio “pop.”

Superior ESD
Protection

Fairchild’s
USB Multimedia
Switches

VBUS
DP_CON
DM_CON
GND

Charger
Detect

Switch
Control

FSA800

-0.4
-0.5

OVT

3:1
MUX
and
Charge
Pump

R

CD_N

ID Detect

Negative Swing
Audio
When used with negative swing capable
amplifiers, AC coupling capacitors can be t
removed, significantly reducing audio “pop”
and improving space savings. All Fairchild
multimedia switches have negative swing
capability.

Power-Off
Protection
Fairchild’s power-off protection ensures
power down off-isolation. This feature is advantageous when signals have a voltage present
before the switch is powered up, or after the
switch is powered down. This feature prevents
unwanted current leakage during power down
and guarantees off-isolation.

Low ICCT For Low
Power Consumption

Saving our world, 1mW at a time™

Superior High Speed USB
and Audio Performance
Over-Voltage
Tolerance (OVT)
Over-voltage tolerance
protection is needed to allow
the switch to fully meet USB2.0
VBUS short requirements without
adding external components.

•t Fairchild multimedia switches support both
t high-speed USB (480Mbps) and full-speed t
t USB (12Mbps).
•t Low CON for USB is critical for achieving t
t USB eye compliance as it limits the amount t
t of edge roll-off and signal distortion.
•t Low R ON is key to optimal audio
t performance.

www.fairchildsemi.com