ISL43110 Datasheet, PDF (8/12 Pages) Intersil Corporation – Low-Voltage, Single Supply, SPST, High Performance Analog Switches

ISL43110, ISL43111
to the electrical specification tables and Typical Performance
Curves for details.
response is very consistent over a wide V+ range, and for
varying analog signal levels.
V+ and GND power the internal CMOS switches and set
their analog voltage limits. These supplies also power the
internal logic and level shifters. The level shifters convert the
input logic levels to switched V+ and GND signals to drive
the analog switch gate terminals.
This family of switches cannot be operated with bipolar
supplies, because the input switching point becomes
negative in this configuration. For a ±5V single SPST switch,
see the ISL43112/13 data sheet.
Logic-Level Thresholds
This switch family is TTL compatible (0.8V and 2.4V) over a
supply range of 3V to 11V, and the full temperature range
(see Figure 10). At 12V the low temperature V_IH level is
about 2.5V. This is still below the TTL guaranteed high
output minimum level of 2.8V, but noise margin is reduced.
For best results with a 12V supply, use a logic family the
provides a V_OH greater than 3V.
The digital input stages draw supply current whenever the
digital input voltage is not at one of the supply rails. Driving
the digital input signals from GND to V+ with a fast transition
time minimizes power dissipation.
High-Frequency Performance
In 50Ω systems, signal response is reasonably flat to
20MHz, with a -3dB bandwidth exceeding 200MHz (see
Figure 15). Figure 15 also illustrates that the frequency
An OFF switch acts like a capacitor and passes higher
frequencies with less attenuation, resulting in signal
feedthrough from a switch’s input to its output. Off Isolation
is the resistance to this feedthrough. Figure 16 details the
high Off Isolation provided by this family. At 10MHz, off
isolation is about 50dB in 50Ω systems, decreasing
approximately 20dB per decade as frequency increases.
Higher load impedances decrease Off Isolation due to the
voltage divider action of the switch OFF impedance and the
load impedance.
Leakage Considerations
Reverse ESD protection diodes are internally connected
between each analog-signal pin and both V+ and GND. One
of these diodes conducts if any analog signal exceeds V+ or
GND.
Virtually all the analog leakage current comes from the ESD
diodes to V+ or GND. Although the ESD diodes on a given
signal pin are identical and therefore fairly well balanced,
they are reverse biased differently. Each is biased by either
V+ or GND and the analog signal. This means their leakages
will vary as the signal varies. The difference in the two diode
leakages to the V+ and GND pins constitutes the analog-
signal-path leakage current. All analog leakage current flows
between each pin and one of the supply terminals, not to the
other switch terminal. This is why both sides of a given
switch can show leakage currents of the same or opposite
polarity. There is no connection between the analog-signal
paths and V+ or GND.
Typical Performance Curves T_A = 25^oC, Unless Otherwise Specified
25
20
V_COM = (V+) - 1V
16
I_COM = 1mA
20
12
8
15
15
13
85^oC
11
10
9
-40^oC 25^oC
7
5
5
9
7
85^oC
25^oC
-40^oC
I_COM = 1mA
85^oC
25^oC
-40^oC
85^oC ₂₅^o_C
V+ = 3.3V
V+ = 5V
V+ = 12V
0
3 4 5 6 7 8 9 10 11 12 13
V+ (V)
FIGURE 7. ON RESISTANCE vs SUPPLY VOLTAGE
5
-40^oC
3
0
2
4
6
8
V_COM (V)
10
12
FIGURE 8. ON RESISTANCE vs SWITCH VOLTAGE
8