ISL54216 Datasheet, PDF (8/17 Pages) Intersil Corporation – USB 2.0 High-Speed/UART Dual SP3T (Dual 3 to 1 Multiplexer)

ISL54216
Application Block Diagrams
USB
TRANSCEIVER
USB
TRANSCEIVER
UART
3D-
3D+
2D-
2D+
1D-
1D+
3.3V
100Ω
VDD
LOGIC CONTROL
C0
4MΩ ^C1
µCONTROLLER
VBUS
COM -
COM +
GND
ISL54216
AUDIO
CODEC
ISL54406
HEAD
PHONE
JACK
Detailed Description
The ISL54216 device consists of dual SP3T (single
pole/triple throw) analog switches. It operates from a
single DC power supply in the range of 2.7V to 4.6V. It
was designed to function as differential 3 to 1 multiplexer
to select between three different differential data signals.
Its offered in tiny µTQFN and TQFN packages for use in
MP3 players, PDAs, cellphones, and other personal media
players.
A device consists of six 6Ω data switches. They were
designed to pass high-speed USB differential data signals
with minimal edge and phase distortion. They can swing
rail-to-rail to pass UART and full-speed USB signals.
The COM pins can accept signals that swing below
ground by as much as -2V. This allows an audio source to
be wired-or connected at the COM pins.
The ISL54216 was specifically designed for MP3 players,
personal media players and cellphone applications that
need to combine three differential data channels into a
single shared connector, thereby saving space and
component cost. This functionality is shown in the Typical
Application Block Diagram.
A detailed description of the switches is provided in the
following sections.
Data Switches
The six data switches (1D+, 1D-, 2D+, 2D-, 3D+, 3D-)
are 6Ω bidirectional switches that were specifically
designed to pass 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 11 and 12 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 (12Mbps) and UART signals with minimal
distortion. See Figure 13 for USB 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_DD. The signal voltage at D- and
D+ should not be allow to exceed the V_DD voltage rail or
go below ground by more than -1V for normal operation.
Fault Protection and Power-Off Protection
However, in the event that the USB 5.25V V_BUS voltage
were shorted to one or both of the COM pins, the
ISL54216 has fault protection circuitry to prevent
damage to the ISL54216 part. The fault circuitry allows
the signal pins (COM-, COM+, 1D-, 1D+, 2D-, 2D+, 3D-,
3D+) to be driven up to 5.25V while the V_DD supply
voltage is in the range of 0V to 4.6V. This fault condition
causes no stress to the IC.
In addition when V_DD is at 0V (ground) all switches are
OFF and the fault voltage is isolated from the other side
of the switch (Power-Off Protection).
When V_DD is in the 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.
ISL54216 Operation
The discussion that follows will discuss using the
ISL54216 in the “Application Block Diagrams” on
page 8.
8
FN7701.0
September 27, 2010