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Multiplexers and Signal Switches
Glossary
Application Report
Literature Number: SLLA471A
MARCH 2020 – REVISED JUNE 2021www.ti.com About This Multiplexers and Signal Switches Glossary
Preface
About This Multiplexers and Signal Switches
Glossary
This glossary provides a brief overview and introduction to the terminology, features, and parameters for
multiplexers and signal switches. The entire switches and multiplexers portfolio can be found at www.ti.com/
switches.
For components used to manage power rails, TI offers a power switch and power multiplexer portfolio which can
each be found at www.ti.com/powerswitch.
SLLA471A – MARCH 2020 – REVISED JUNE 2021 Multiplexers and Signal Switches Glossary 3
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com Contents
Contents
Table of Contents
1. Introduction to Multiplexers and Signal Switches 2. Operation of Multiplexers and Signal Switches
• Signal switch • Absolute maximum ratings
• Multiplexer (Mux) • Recommended operating conditions
• Analog switches and multiplexers • Single power supply
• Protocol-specific switches and multiplexers • Dual power supply
• Power multiplexer • Switch control signal levels (VIH, VIL)
• Power switch • Rail-to-rail
• Precision • Input/Output voltage beyond supply
• Protection • Bidirectional signal path
• Low voltage
• Mid voltage
• Configuration
• Channel
3. Additional Features 4. DC Characteristics
• 1.8-V control logic • On-resistance (RON)
• Fail-safe logic • On-resistance flatness (RON FLAT)
• Injection current control • OFF leakage current (ID(OFF), IS(OFF))
• Integrated pulldown resistor on logic pin • Powered-off I/O pin leakage current (IPOFF)
• Latch-up immunity • ON leakage current (ID(ON), IS(ON))
• Overvoltage protection • Control input leakage (ISEL or IEN)
• Powered-off protection
5. Dynamic Characteristics 6. Timing Characteristics
• Off capacitance source and drain (COFF) • Transition time (tTRAN)
• On capacitance source and drain (CON) • Device turn on time from enable pin (tON(EN) and tOFF(EN))
• Charge injection (QC) • Break-before-make time (tOPEN (BBM))
• Off-isolation (OISO) • Make-before-break time (tCLOSED (MBB))
• Channel-to-channel crosstalk (XTALK) • Output-to-output skew (tSK)
• Bandwidth (BW) • Propagation delay through the switch (tpd)
SLLA471A – MARCH 2020 – REVISED JUNE 2021 Multiplexers and Signal Switches Glossary 5
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com Introduction to Multiplexers and Signal Switches
Chapter 1
Introduction to Multiplexers and Signal Switches
S D
Signal switch — An integrated circuit (IC) used for connecting and disconnecting
an electrical circuit. For more information, see the Switches and muxes: What are
switches & multiplexers? training video from TI Precision Labs.
Figure 1-1. Ideal 1:1 SPST Switch
A0 A1
S1
S2
D
Multiplexer (Mux) — An integrated circuit that connects a selected signal path to a S3
single line.
S4
Figure 1-2. Ideal 4:1 Mux
Analog switches and multiplexers — These devices are used for switching and multiplexing analog and digital signals up to 500 mA in
applications such as:
• Precision data acquisition
• GPIO expansion and diagnostics
• System communication and bus isolation
• System protection and power sequencing
• General-purpose signal switching
Protocol-specific switches and multiplexers — These devices are defined to support specific protocol applications such as USB, HDMI,
LAN, MIPI, audio, memory and so forth.
Power multiplexer — These devices are a set of electronic switches used to select and transition between two or more input power paths
to a single output.
Power switch — These devices manage power distribution for paths typically greater than 500 mA between a voltage source to a load.
They can be used to limit inrush current, enable power sequencing, provide protection from overvoltage or overcurrent events, and more.
Precision — These devices minimize offset error and signal distortion in a high-accuracy measurement system.
Protection — These devices isolate I/O signal paths and protect the system using powered-off, overvoltage and undershoot protection.
Low voltage — These devices support I/O signals ≤ ±24 V
Mid voltage — These devices support I/O signals > ±24 V
Configuration — Defines the number of signals that can be selected. Table 1-1 shows the typical configurations.
Channel — Defines the number of configurations (circuits) in a single device. Table 1-1 shows the 1- and 2- channel configurations, but the
number of channels may exceed 2.
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Table 1-1. Configurations and Channels
1-Channel 2-Channel
S1 D1
S D
1:1 S2 D2
S1A
D1
S1 S1B
D
2:1 S2 S2A
D2
S2B
S1A
S2B D1
S1
S1C
S2 D
3:1 S2A
Configuration
S3
S2B D2
S2C
S1A
S1B
D1
S1
S1C
S2
S1D
D
4:1 S3 S2A
S2B
S4
D2
S2C
S2D
8 Multiplexers and Signal Switches Glossary SLLA471A – MARCH 2020 – REVISED JUNE 2021
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com Introduction to Multiplexers and Signal Switches
Table 1-1. Configurations and Channels (continued)
1-Channel 2-Channel
S1A
S1B
S1C
S1D
D1
S1 S1E
S2 S1F
S3 S1G
S4 S1H
D
Configuration 8:1 S5 S2A
S6 S2B
S7 S2C
S8 S2D
D2
S2E
S2F
S2G
S2H
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com Operation of Multiplexers and Signal Switches
Chapter 2
Operation of Multiplexers and Signal Switches
Absolute maximum ratings — These are stress ratings only, which do not imply functional operation of the device at these or any other
conditions beyond those indicated under the Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for
extended periods may affect device reliability. Stresses beyond those listed under the Absolute Maximum Rating may cause permanent
damage to the device.
Recommended operating conditions — The operating conditions for which the device has been characterized.
Single Dual
Supply: Supply:
VDD (+V)
Single power supply — Device with only positive power supply pins with
reference to ground. The voltage applied is labeled as VDD, VCC, V+ and so
forth. GND
Dual power supply — Device with positive and negative supply pins with
reference to ground. Voltage applied at the positive pin is labeled as VDD, VCC,
V+, and so forth, and at the negative pin is labeled as VSS, VEE, V-, and so
forth.
VSS (-V)
Figure 2-1. Single and Dual Supply
V DD
Log ic
Switch control signal levels (VIH, VIL) — Voltage levels required on the ³HIG H´
control pins (EN, SEL, IN, and so forth) required for the switch to change the
internal signal path. VIH
• VIH – The minimum voltage for the input control signal to achieve a logic
"1"high value VIL
Log ic
• VIL – The maximum voltage for the input control signal to remain a logic
³LOW´
"0"low value GND
Figure 2-2. Switch Control Signal Levels
VDD
VI/O
Rail-to-rail — A common term meaning that a device will support VI/O voltage
range between the most positive and most negative power supply rails.
0V
(GND)
t
Figure 2-3. Rail-to-Rail
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VI/O(MAX)
VDD
Input/Output voltage beyond supply – The switch can support voltage range
beyond the supply rail to VI/O(MAX)as indicated by the recommended operating
conditions.
0V
(GND)
t
Figure 2-4. I/O Voltage Beyond Supply
A0 A1
S1
S2
Bidirectional signal path – The switch conducts equally well from source
(S) to drain (D) or from drain (D) to source (S). Each channel has very D
similar characteristics in both directions and supports both analog and digital S3
signals. TI analog switches and multiplexers are typically bidirectional. See the
Switches and muxes: Are switches & multiplexers bidirectional? training video S4
from TI Precision Labs.
Figure 2-5. Bidirectional Signal Path
12 Multiplexers and Signal Switches Glossary SLLA471A – MARCH 2020 – REVISED JUNE 2021
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com Additional Features
Chapter 3
Additional Features
1.8-V control logic – Switches with this feature have a built-in voltage translator to prevent voltage mismatch between the supply rail and
the control logic. VIH and VIL levels are compatible with the 1.8-V logic levels at any voltage supply. See the Simplifying Design With 1.8 V
logic MUXes and Switches Tech Note for more information.
VDD = 0 V
VCC = 5 V VDD
Protection
VSEL
Fail-safe logic – Ensures the switch stays off and 0V
the voltage on the logic pin (VSEL) does not back-
Subsystem SEL
power VDD when VSEL is greater than VDD. See the A
Switches and muxes: What is fail-safe logic? training
Subsystem
video from TI Precision Labs. B
S High-Z D
Figure 3-1. Fail-Safe Logic
Injection current control — Allows signals on S1 D
disabled (high-Z) signal paths to exceed the supply
voltage without affecting the signal of the enabled Control
signal path. For example, if current is injected into Circuitry
a disabled signal path, raising the voltage at the
S2
pin above the supply, the signal on the enabled
signal path will not be affected. See the Switches
Control
and muxes: Prevent crosstalk with injection current + Circuitry
control training video from TI Precision Labs.
±
Figure 3-2. Injection Current Control
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Copyright © 2021 Texas Instruments IncorporatedAdditional Features www.ti.com
VDD
S D
EN
Integrated pulldown resistor on logic pin –
Internal weak pulldown resistors to GND to ensure
the logic pins are not floating.
GND
Figure 3-3. Integrated Pulldown Resistor on Logic Pin
NMOS PMOS VDD
Gate Gate
GND
Latch-up immunity – Devices that are latch-up
Trench Oxide
Trench Oxide
Trench Oxide
immune are built in a Silicon On Insulator (SOI) p+ n+ n+ p+ p+ n+
process and will not latch-up when exposed to
current injection or overvoltage events. See the p-epi n-well
Switches and muxes: What is latch-up immunity?
training video from TI Precision Labs.
Buried Oxide Layer (Insulator)
Substrate (p) / Handle
Figure 3-4. Latch-Up Immunity With SOI Process
VI/O(MAX)
Switch
³2))´
Overvoltage protection – When the input voltage VTH VI/O
VI/O exceeds the defined threshold voltage, VTH,
the switch enters the high impedance state, isolates
signal path, and protects downstream components. 6ZLWFK ³21´
VI/O(MIN)
Figure 3-5. Overvoltage Protection
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com Additional Features
VDD = 0 V
VDD
Powered-off protection – Protects switch and VCC = 5 V
isolates signal path when signals are present at the Pro tection
I/O pins and VDD = 0 V. See the Switches and SEL
muxes: Simplify power sequencing with powered-off VS
protection training video from TI Precision Labsand Sub system 0 V IS Sub system
the Eliminate Power Sequencing With Powered-off A S High-Z D B
Protection Signal Switches Tech Note for more
information.
Figure 3-6. Powered-Off Protection
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com DC Characteristics
Chapter 4
DC Characteristics
For more parameter information, see the device data sheet.
VDD
RON
S1 D1
On-resistance (RON) — The resistance inserted into the signal path as a
result of the switch path being turned on. +
VS RL
± Switch ON
Figure 4-1. On-Resistance
RON FLAT ( )
Flatness
On-resistance flatness (RON FLAT) — Difference between the maximum and
minimum value of Ron in a channel over the VD or VS voltage range.
VD or VS (V)
Figure 4-2. On-Resistance Flatness
VDD
S1 S D D1
Hi-Z
OFF leakage current (ID(OFF), IS(OFF)) — Leakage current measured at the + ID(OFF)
input port, with the corresponding channel output in the OFF state under VS RL
±
worst-case input and output conditions.
Switch OFF
Figure 4-3. OFF Leakage Current
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0V
Protection
IPOFF
S1 S Hi-Z D D1
Powered-off I/O pin leakage current (IPOFF) — The leakage current flowing +
into or out of the source pin when the device is powered off (VDD = 0V). VS RL
±
Switch OFF
Figure 4-4. Powered-Off I/O Pin Leakage
Current
VDD
IS ID
S1 S D1
ON D
+ ID(ON)
ON leakage current (ID(ON), IS(ON)) — Leakage current measured at the input VS RL
or
port in the ON state, with the corresponding output port in the ON state and ±
IS(ON)
the output being open.
Switch ON
IS • ,D
Figure 4-5. ON Leakage Current
VDD
S1 S Hi-Z D D1
Control input leakage (ISEL or IEN) — Leakage measured at the switch EN
control pins. VSEL ISEL
or or
IEN
VEN
Switch OFF
Figure 4-6. Control Input Leakage
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com Dynamic Characteristics
Chapter 5
Dynamic Characteristics
For detailed information of dynamic characteristics, see the Multiplexers: Bandwidth, Channel-to-Channel
Crosstalk, Off-Isolation and THD+Noise training video from TI Precision Labs.
For more parameter information, see the device data sheet.
VDD
S1 S Hi-Z D D1
COFF
Off capacitance source and drain (COFF) — The capacitive loading when a
switch path is in the high-impedance state. VS RL
Switch OFF
Figure 5-1. Source and Drain Off Capacitance
VDD
S1 S ON D D1
CS(ON) CD(ON)
On capacitance source and drain (CON) — The capacitive loading when a
VS RL
switch path is in the low-impedance state.
Switch ON
CON = CS(ON) + CD(ON)
Figure 5-2. Source and Drain On Capacitance
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VDD
S1 S D D1
+
VS EN CL RL
±
VE
N
Charge injection (QC) — Charge injection is a measurement of unwanted
VDD
signal coupling from the control (EN) input to the analog output. This is VEN
measured in coulomb (C) and measured by the total charge induced due to
switching of the control input. 0V
VDD
¨9D1
VD1
¨9D1
0V
QC = CL * ¨9D
Figure 5-3. Charge Injection
VDD
VS1
VD1
S1 S D D1
Hi-Z
Off-isolation (OISO) — A measurement OFF-state switch impedance. This
is the ratio of VD1 to VS1 measured in dB at a specific frequency, with the VS RL
corresponding channel in the OFF state. Switch OFF
Figure 5-4. Off-Isolation
VDD
VS1
S1 S ON D D1
+
VS1 RL
±
Channel-to-channel crosstalk (XTALK) — A measurement of unwanted
signal coupling from an ON channel to an OFF channel. This is the ratio VS2
S2 S Hi-Z D D2
of VS2 to VS1 measured in dB at a specific frequency.
+
VS2 RL
±
XTALK =
Figure 5-5. Channel-to-Channel Crosstalk
20 Multiplexers and Signal Switches Glossary SLLA471A – MARCH 2020 – REVISED JUNE 2021
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Magnitude (dB)
í3 dB
Ban dwidth
Bandwidth (BW) — The frequency range of signals that can pass through
the switch with no more than 3 dB of attenuation.
Freque ncy (Hz)
Figure 5-6. Bandwidth
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com Timing Characteristics
Chapter 6
Timing Characteristics
For detailed information, see the Switches and muxes: What are timing characteristics? training video from TI
Precision Labs.
For more parameter information, see the device data sheet.
VDD
S1 S D D1
ON
+
VS RL
±
SEL
VSEL Switch ON
Transition time (tTRAN) — The time taken by the switch output to rise or fall
within a given percentage of the final value after the address signal has risen
or fallen past the logic threshold. VDD
VIH
VSEL
VIL
0V
tTRAN
VS
90%
VD1
10%
0V
Figure 6-1. Transition Time
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VDD
S1 S ON D D1
+ EN
VS RL
±
Switch ON
VEN
Device turn on time from enable pin
(t ON(EN) and t OFF(EN) ) — The time taken by the switch output to rise or fall VDD
VIH
within a given percentage of the final value after the enable has risen or fallen VEN
past the logic threshold. VIL
0V
tON (EN) tOFF (EN)
VS
90% 90%
VD1
0V
Figure 6-2. Device Turn on Time From Enable
Pin
VDD
S1A S D D1
+ RL CL
VS
±
S1B S D
SEL
VSEL
Break-before-make time (tOPEN (BBM)) — Ensures that in a multiplexer, two
multiplexer paths are never electrically connected when the signal path is
changed by the select input.
VDD
VSEL
0V
VS
90%
VD1
tBBM1 tBBM2
0V
tOPEN (BBM) = min ( tBBM1, tBBM2)
Figure 6-3. Break-Before-Make Time
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VDD
S1 S D D1A
+ RL CL
VS
±
S D D 1B
SEL
RL CL
VSEL
Make-before-break time (tCLOSED (MBB)) — Ensures that in a multiplexer, two
multiplexer paths are never electrically disconnected when the signal path is
changed by the select input. VDD
VSEL VIH
0V
VS
90%
VD1A
0V
VS
90%
VD1B
0V
tCL OS ED (MBB)
Figure 6-4. Make-Before-Break Time
VDD
S1 S ON D D1
+
VS RL
±
S2 S ON D D2
+
VS RL
±
Output-to-output skew (tSK) — The maximum difference between the Switches ON
propagation delays of different outputs due to different internal paths.
VS
VD1 50% 50%
0V
tSK1 tSK2
VS
VD2 50% 50%
0V
tSK = max ( tSK1, tSK2)
Figure 6-5. Output-to-Output Skew
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VDD
S1 S ON D D1
+
VS RL
± Switch ON
VS
Propagation delay through the switch (tpd) — The time required for a VS1 50% 50%
signal to pass from the input signal pin to the respective output signal pin. 0V
tPD 1 tPD 2
VS
VD1 50
50%
%
0V
tpd = max ( tPD 1, tPD 2)
Figure 6-6. Propagation Delay Through the
Switch
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Copyright © 2021 Texas Instruments Incorporatedwww.ti.com Revision History
Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision * (March 2020) to Revision A (June 2021) Page
• Updated the numbering format for tables, figures and cross-references throughout the document...................7
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