ISL84051IVZ Intersil, ISL84051IVZ Datasheet - Page 13

• Manufacturer Part Number: ISL84051IVZ
• Description: IC MUX/DEMUX 8X1 16TSSOP
• Manufacturer: Intersil

Specifications of ISL84051IVZ

• Function: Multiplexer/Demultiplexer
• Circuit: 1 x 8:1
• On-state Resistance: 225 Ohm
• Voltage Supply Source: Single, Dual Supply
• Voltage - Supply, Single/dual (±): ±2 V ~ 6 V, 2 V ~ 12 V
• Current - Supply: 1µA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

purpose of using a low r
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-. The low leakage current performance is
unaffected by this approach, but the switch resistance may
increase, especially at low supply voltages.
Power-Supply Considerations
The ISL8405x construction is typical of most CMOS analog
switches, in that they have three supply pins: V+, V-, and
GND. V+ and V- drive the internal CMOS switches and set
their analog voltage limits, so there are no connections
between the analog signal path and GND. Unlike switches
with a 13V maximum supply voltage, the ISL8405x 15V
maximum supply voltage provides plenty of room for the
10% tolerance of 12V supplies (±6V or 12V single supply),
as well as room for overshoot and noise spikes.
This family of switches performs equally well when operated
with bipolar or single voltage supplies. The minimum
recommended supply voltage is 2V or ±2V. It is important to
note that the input signal range, switching times, and
ON-resistance degrade at lower supply voltages. Refer to
the “Electrical Specification” tables beginning on page 5 and
“Typical Performance Curves” beginning on page 14 for
details.
V+ and GND power the internal logic (thus setting the digital
switching point) and level shifters. The level shifters convert
the logic levels to switched V+ and V- signals to drive the
analog switch gate terminals.
OPTIONAL
PROTECTION
RESISTOR
FOR LOGIC
INPUTS
FIGURE 8. INPUT OVERVOLTAGE PROTECTION
1kΩ
V
LOGIC
NO OR NC
ON
switch, so two small signal
13
V-
V+
OPTIONAL PROTECTION
DIODE
OPTIONAL PROTECTION
DIODE
ISL84051, ISL84052, ISL84053
V
COM
Logic-Level Thresholds
V+ and GND power the internal logic stages, so V- has no
affect on logic thresholds. This switch family is TTL
compatible (0.8V and 2.4V) over a V+ supply range of 2.7V
to 10V. At 12V the V
the CMOS guaranteed high output minimum level of 4V, but
noise margin is reduced. For best results with a 12V supply,
use a logic family that provides a V
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 even past
100MHz (see Figure 17). Figure 17 also illustrates that the
frequency response is very consistent over varying analog
signal levels.
An OFF switch acts like a capacitor and passes higher
frequencies with less attenuation, resulting in signal feed
through from a switch’s input to its output. Off isolation is the
resistance to this feed through, while crosstalk indicates the
amount of feed through from one switch to another.
Figure 18 details the high off isolation and crosstalk rejection
provided by this family. At 10MHz, off isolation is about 55dB
in 50Ω systems, decreasing approximately 20dB per decade
as frequency increases. Higher load impedances decrease
off isolation and crosstalk rejection 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 V-. One
of these diodes conducts if any analog signal exceeds V+
or V-.
Virtually all the analog leakage current comes from the ESD
diodes to V+ or V-. 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 V- 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 V- 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 GND.
IH
level is about 3.5V. This is still below
OH
greater than 4V.
October 8, 2010
FN6047.9