ISL43240_14 Datasheet, PDF (8/15 Pages) Intersil Corporation – Low-Voltage, Single and Dual Supply, Quad SPDT, High Performance Analog Switch

ISL43240
Test Circuits and Waveforms (Continued)
V+
C
SIGNAL
GENERATOR
NO or NC
IN ^{0V or 2.4V}
ANALYZER
R_L
COM
GND
C
V-
Repeat test for all switches.
FIGURE 4. OFF ISOLATION TEST CIRCUIT
V+
C
r_ON = V₁/1mA
V_NX
NO or NC
1mA
V₁
V+
C
IN
0.8V or 2.4V
COM
GND
C
V-
Repeat test for all switches.
FIGURE 5. R_ON TEST CIRCUIT
V+
SIGNAL
GENERATOR
NO1 or NC1
COM1
50Ω
NO or NC
IN₁
0V or 2.4V
IN₂ ^{0V or 2.4V}
ANALYZER
R_L
COM2
NO2 or NC2
GND
NO
CONNECTION
C
V-
FIGURE 6. CROSSTALK TEST CIRCUIT
IMPEDANCE
ANALYZER
IN 0V or 2.4V
COM
GND
V-
FIGURE 7. CAPACITANCE TEST CIRCUIT
Detailed Description
The ISL43240 quad analog switches offer precise switching
capability from a bipolar 2V to 6V or a single 2V to 12V supply
with low on-resistance (18Ω) and high speed operation
(t_ON = 52ns, t_OFF = 40ns). The devices are especially well suited
for portable battery powered equipment thanks to the low
operating supply voltage (2V), low power consumption (5µW), low
leakage currents (5nA max). High frequency applications also
benefit from the wide bandwidth, and the very high off isolation
and crosstalk rejection.
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. All I/O pins contain
ESD protection diodes from the pin to V+ and to V- (see Figure 8).
To prevent forward biasing these diodes, V+ and V- must be
applied before any input signals, and input signal voltages must
remain between V+ and V-. If these conditions cannot be
guaranteed, then one of the following two protection methods
should be employed.
Logic inputs can easily be protected by adding a 1kΩ resistor in
series with the input (see Figure 8). The resistor limits the input
current below the threshold that produces permanent damage,
and the sub-microamp input current produces an insignificant
voltage drop during normal operation.
Adding a series resistor to the switch input defeats the purpose of
using a low r_ON switch, so two small signal diodes can be added in
series with the supply pins to provide overvoltage protection for all
pins (see Figure 8). These additional diodes limit the analog signal
from 1V below V+ to 1V above V-.
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8
FN6036.3
December 15, 2014