ISL54214 Datasheet, PDF (12/22 Pages) Intersil Corporation – USB 2.0 High-Speed x 2 Channels/Stereo Audio Dual SP3T Dual 3-to-1 Multiplexer

ISL54214
mode, the computer or USB hub transceiver and the MP3
player or cellphone USB transceiver #2 are connected
and digital data will be able to be transmit back and
forth.
Audio MUTE Mode
If the C1 pin = Logic “1” and C0 pin = Logic “0”, the part
will be in the Audio Mute mode provided that the last
state was the Audio state. In the Audio Mute mode, the
2D- and 2D+ USB switches, the L and R audio switches
and the 1D- and 1D+ USB switches will be OFF (high
impedance).
The 1kΩ COM shunt resistors will be connected (ON). The
1kΩ shunts provide 77dB of off-isolation when driving
10kΩ to 20kΩ amplifier inputs.
The 1kΩ COM shunt resistors are active (ON) only when
in the Audio Mute mode.
Logic Control Timing Between C1 and C0
The ISL54214 has a unique logic control architecture.
The part has five different logic states but only two
external logic control pins, C1 and C0. Refer to the “State
Diagram” on page 2 and “Truth Table” on page 2.
The following state transitions require both C1 and C0
logic control bits to change their logic levels in unison:
All OFF(C1 = 0, C0 = 0) -----> Audio (C1 = 1, C0 = 1)
Audio (C1 = 1, C0 = 1) -----> All OFF (C1 = 0, C0 = 0)
Audio Mute (C1 = 1, C0 = 0) -----> USB1 (C1 = 0, C0 = 1)
The delay time between these bits must be < 100ns to
ensure that you directly move between these states
without momentarily transitioning to one of the other
states.
For example, if you are going from the “All OFF” state to
the “Audio” state and C0 does not go high until 100nS
after C1 went high you will momentarily transition to the
“USB2” state. Any signals connected at the USB2 signal
lines will momentarily get passed through to the COM
outputs.
Delay time between C1 and C0 must be < 100ns and
should be controlled by logic control drivers with well
behaved monotonic transitions from High to Low and Low
to High and with typical logic family rise and fall times of
1ns to 6ns.
POWER
The power supply connected at VDD (pin 11) provides
power to the ISL54214 part. Its voltage should be kept in
the range of 2.7V to 4.6V. In a typical application, V_DD
will be in the range of 2.7V to 4.3V and will be connected
to the battery or LDO of the MP3 player or cellphone.
A 0.01µF or 0.1µF decoupling capacitor should be
connected from the VDD pin to ground to filter out any
power supply noise from entering the part. The capacitor
should be located as close to the VDD pin as possible.
Typical Performance Curves T_A = +25°C, Unless Otherwise Specified.
2.95
2.90
2.85
2.80
I_COM = 60mA
2.60
2.58
I_COM = 60mA
2.56
V_DD = 3.0V
2.75
2.70
2.65
2.60
V_DD = 2.7V
2.55
2.50
V_DD = 3.6V
V_DD = 4.6V
2.45
-1.5
-1.0
-0.5
0
0.5
1.0
1.5
V_COM (V)
FIGURE 8. AUDIO ON-RESISTANCE vs SUPPLY
VOLTAGE vs SWITCH VOLTAGE
2.54
V_DD = 3.3V
V_DD = 3.6V
2.52
V_DD = 4.0V
2.50
V_DD = 4.6V
2.48
-1.5 -1.0 -0.5
0
0.5
1.0
1.5
V_COM (V)
FIGURE 9. AUDIO ON-RESISTANCE vs SUPPLY
VOLTAGE vs SWITCH VOLTAGE
12
FN6816.3
June 28, 2010