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IDTQS3257
HIGH-SPEED CMOS QUICKSWITCH QUAD 2:1 MUX/DEMUX INDUSTRIAL TEMPERATURE RANGE
FEBRUARY 2001
2001 Integrated Device Technology, Inc. DSC-5756/6c
IDTQS3257
INDUSTRIAL TEMPERATURE RANGE
QUICKSWITCH® PRODUCTS
HIGH-SPEED CMOS
QUICKSWITCH
QUAD 2:1 MUX/DEMUX
FUNCTIONAL BLOCK DIAGRAM
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
FEATURES:
• Enhanced N channel FET with no inherent diode to Vcc
•5
ΩΩ
ΩΩ
Ω bidirectional switches connect inputs to outputs
• Pin compatible with the 74F257, 74FCT257, and 74FCT257T
• Zero propagation delay, zero ground bounce
• Undershoot clamp diodes on all switch and control inputs
• TTL-compatible control inputs
• Available in SOIC, QSOP, and S1 packages
APPLICATIONS:
• Logic replacement
• Video, audio, graphics switching, muxing
• Hot-swapping, hot-docking
• Voltage translation (5V to 3.3V)
• Bus funneling
DESCRIPTION:
The QS3257 is a high-speed CMOS LVTTL-compatible Quad 2:1
multiplexer/demultiplexer. The QS3257 is a function and pinout compatible
QuickSwitch version of the 74F257, 74FCT257, and the 74ALS/AS/LS257
Quad 2:1 multiplexers. The low ON resistance of the QS3257 allows inputs
to be connected to outputs without adding propagation delay and without
generating additional ground bounce noise.
Mux/Demux devices provide an order of magnitude faster speed than
equivalent logic devices.
The QS3257 is characterized for operation at -40°C to +85°C.
S
E
YAI0A
I1A
YB
YC
YD
I0B
I1B
I0C
I1C
I0D
I1D
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INDUSTRIAL TEMPERATURE RANGE
IDTQS3257
HIGH-SPEED CMOS QUICKSWITCH QUAD 2:1 MUX/DEMUX
PIN CONFIGURATION
SOIC/ QSOP/ S1
TOP VIEW
NOTE:
1 . H = HIGH Voltage Level
L = LOW Voltage Level
X = Don't Care
Z = High-Impedance
FUNCTION TABLE(1)
Enable Outputs
ESYAYBYCYDFunction
H X Hi-Z Hi-Z Hi-Z Hi-Z Disconnected
LLI0A I0B I0C I0D Select 0
LHI
1A I1B I1C I1D Select 1
Symbol Description Max Unit
VTERM(2) Supply Voltage to Ground –0.5 to +7 V
VTERM(3) DC Switch Voltage Vs –0.5 to +7 V
VTERM(3) DC Input Voltage VIN –0.5 to +7 V
VAC AC Input Voltage (pulse width ≤ 20ns) –3 V
IOUT DC Output Current 120 mA
PMAX Maximum Power Dissipation (TA = 85°C) 0.5 W
TSTG Storage Temperature –65 to +150 °C
ABSOLUTE MAXIMUM RATINGS(1)
NOTE:
1 . Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
2. Vcc terminals.
3. All terminals except Vcc.
CAPACITANCE
(TA = +25°C, f = 1.0MHZ, VIN = 0V, VOUT = 0V)
NOTE:
1. This parameter is measured at characterization but not tested.
Pins Typ. Max. (1) Unit
Control Pins 4 5 pF
Quickswitch Channels Demux 5 7 pF
(Switch OFF) Mux 8 9
PIN DESCRIPTION
Pin Names I/O Description
Ixx I Data Inputs
S I Select Input
EI Enable Input
YA - YDO Data Outputs
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
S
I0A
I1A
YA
GND
VCC
E
I0B
I1B
YB
I0D
I1D
YD
I0C
I1C
YC
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IDTQS3257
HIGH-SPEED CMOS QUICKSWITCH QUAD 2:1 MUX/DEMUX INDUSTRIAL TEMPERATURE RANGE
RON
(ohms)
VIN
(Volts)
TYPICAL ON RESIST ANCE vs VIN AT VCC = 5V
Symbol Parameter Test Conditions Min. Typ.(1) Max. Unit
VIH Input HIGH Level Guaranteed Logic HIGH for Control Pins 2 — — V
VIL Input LOW Level Guaranteed Logic LOW for Control Pins — — 0.8 V
IIN Input LeakageCurrent (Control Inputs)(2) 0V ≤ VIN ≤ VCC ——±1µA
IOZ Off-State Output Current (Hi-Z) 0V ≤ VOUT ≤ VCC ——±1µA
RON Switch ON Resistance VCC = Min., VIN = 0V, ION = 30mA — 5 7 Ω
VCC = Min., VIN = 2.4V, ION =15mA — 10 15
VPPass Voltage(2) VIN = VCC = 5V, IOUT = -5µA 3.7 4 4.2 V
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: TA = –40°C to +85°C, VCC = 5.0V ±5%
NOTES:
1. Typical values are at VCC = 5.0V, TA = 25°C.
2. Pass Voltage is guaranteed but not production tested.
16
14
12
10
8
6
4
2
00.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
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INDUSTRIAL TEMPERATURE RANGE
IDTQS3257
HIGH-SPEED CMOS QUICKSWITCH QUAD 2:1 MUX/DEMUX
POWER SUPPLY CHARACTERISTICS
Symbol Parameter Test Conditions(1) Max. Unit
ICCQ Quiescent Power Supply Current VCC = Max., VIN = GND or Vcc, f = 0 3 µA
∆ICC Power Supply Current per Control Input HIGH (2) VCC = Max., VIN = 3.4V, f = 0 1.5 mA
ICCD Dynamic Power Supply Current per MHz(3) VCC = Max., I and Y pins open 0.25 mA/MHz
Control Inputs Toggling at 50% Duty Cycle
NOTES:
1. For conditions shown as Min. or Max., use the appropriate values specified under DC Electrical Characteristics.
2. Per TLL driven input (VIN = 3.4V, control inputs only). I and Y pins do not contribute to ∆Icc.
3. This current applies to the control inputs only and represents the current required to switch internal capacitance at the specified frequency. The I and Y inputs generate no significant
AC or DC currents as they transition. This parameter is guaranteed but not production tested.
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
TA = -40°C to +85°C, VCC = 5.0V ± 5%;
CLOAD = 50pF, RLOAD = 500Ω unless otherwise noted.
Symbol Parameter Min. (1) Typ. Max. Unit
tPLH Data Propagation Delay (2,3) — — 0.25(3) ns
tPHL Ix to Y
tPZH Switch Turn-on Delay 0.5 — 5.2 ns
tPZL Sx to Y
tPZH Switch Turn-on Delay 0.5 — 4.8 ns
tPZL Ex to Y
tPHZ Switch Turn-off Delay (2) 0.5 — 5 ns
tPLZ Ex to Y, Sx to Y
NOTES:
1. Minimums are guaranteed but not production tested.
2. This parameter is guaranteed but not production tested.
3. The bus switch contributes no propagation delay other than the RC delay of the ON resistance of the switch and the load capacitance. The time constant for the switch alone
is of the order of 0.25ns for CL = 50pF. Since this time constant is much smaller than the rise and fall times of typical driving signals, it adds very little propagation delay to
the system. Propagation delay of the bus switch, when used in a system, is determined by the driving circuit on the driving side of the switch and its interaction with the load
on the driven side.
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IDTQS3257
HIGH-SPEED CMOS QUICKSWITCH QUAD 2:1 MUX/DEMUX INDUSTRIAL TEMPERATURE RANGE
ORDERING INFORMATION
CORPORATE HEADQUARTERS for SALES: for Tech Support:
2975 Stender Way 800-345-7015 or 408-727-6116 logichelp@idt.com
Santa Clara, CA 95054 fax: 408-492-8674 (408) 654-6459
www.idt.com
IDTQS XXXXX XX
Package
Device Type
Small Outline IC
Quarter Size Outline Package
Small Outline IC
SOIC - Green
SO
Q
S1
S1G
3257 H igh Speed CMOS Quickswitch Quad 2:1 Mux/Demux
