9
FN6582.1
November 3, 2009
Detailed Description
The ISL54063 and ISL54064 are bidirectional, dual single
pole-single throw (SPST) analog switches that offers precise
switching from a single 1.8V to 6.5V supply with low
ON-resistance (0.83Ω), high speed operation (t
ON
= 55ns,
t
OFF
= 18ns) and negative signal swing capability. The
device is especially well suited for portable battery powered
equipment due to its low operating supply voltage (1.8V), low
power consumption (20nA), and a tiny 1.8mmx1.4mm µTQFN
package or a 3mmx3mm TDFN package. The low
ON-resistance and r
ON
flatness provide very low insertion
loss and signal distortion for applications that require signal
switching with minimal interference by the switch.
The ISL54063 is a normally open (NO) SPST analog switch.
The ISL54064 is a normally closed (NC) SPST analog
switch.
Supply Sequencing and Overvoltage Protection
With any CMOS device, proper power supply sequencing is
required to protect the device from excessive input currents
which might permanently damage the IC. The ISL54063 and
ISL54064 contains ESD protection diodes on each pin of the
IC (see Figure 8). These diodes connect to either a +Ring or
-Ring for ESD protection. To prevent forward biasing the
ESD diodes to the +Ring, V+ must be applied before any
input signals, and the input signal voltages must remain
between recommended operating range.
If these conditions cannot be guaranteed, then precautions
must be implemented to prohibit the current and voltage at
the logic pin and signal pins from exceeding the maximum
ratings of the switch. The following two methods can be used
to provided additional protection to limit the current in the
event that the voltage at a logic pin or switch terminal goes
above the V+ rail.
Logic inputs can be protected by adding a 1kΩ resistor in
series with the logic input (see Figure 8). The resistor limits
the input current below the threshold that produces
permanent damage.
FIGURE 5. CROSSTALK TEST CIRCUIT
FIGURE 6. CAPACITANCE TEST CIRCUIT
FIGURE 7A. CLICK AND POP WAVEFORM
FIGURE 7B. CLICK AND POP TEST CIRCUIT
FIGURE 7. CLICK AND POP ELIMINATION
Test Circuits and Waveforms (Continued)
0V OR V+
ANALYZER
V+
C
NO1 OR NC1
SIGNAL
GENERATOR
R
L
GND
IN
X
COM1
50Ω
NC
COM2
NC2 OR NO2
Signal direction through switch is reversed, worst case values
are recorded. Repeat test for all switches.
*50Ω SOURCE
V+
C
GND
NO OR NC
COM
IN
IMPEDANCE
ANALYZER
0V OR V+
t
D
V
DC
V
INx
*
*V
INx
waveform for Click and Pop Elimination on NOx terminal.
For Click and Pop Elimination on NCx terminal invert V
INx
.
t
D
= 200ms measured at 50% points.
0V
0V
t
D
CLICK AND POP
CIRCUITRY
R
L
220µF
220µF
INx
COMx
NCx
NOx
V
DC
V
DC
ISL54063, ISL54064