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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-5756/4
c
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
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 -40C to +85C.
S
E
Y
A
I
0A
I
1A
Y
B
Y
C
Y
D
I
0B
I
1B
I
0C
I
1C
I
0D
I
1D
2
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
E
S
S
1
S
0
Y
A
Y
B
Function
H
X
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Disconnected
L
L
I
0A
I
0B
I
0C
I
0D
Select 0
L
H
I
1A
I
1B
I
1C
I
1D
Select 1
Symbol
Description
Max
Unit
V
TERM
(2)
Supply Voltage to Ground
0.5 to +7
V
V
TERM
(3)
DC Switch Voltage Vs
0.5 to +7
V
V
TERM
(3)
DC Input Voltage V
IN
0.5 to +7
V
V
AC
AC Input Voltage (pulse width
20ns)
3
V
I
OUT
DC Output Current
120
mA
P
MAX
Maximum Power Dissipation (T
A
= 85C)
0.5
W
T
STG
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
(T
A
= +25C, f = 1.0MH
Z
, V
IN
= 0V, V
OUT
= 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
E
I
Enable Input
Y
A
- Y
D
O
Data Outputs
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
S
I
0A
I
1A
Y
A
GND
V
CC
E
I
0B
I
1B
Y
B
I
0D
I
1D
Y
D
I
0C
I
1C
Y
C
3
IDTQS3257
HIGH-SPEED CMOS QUICKSWITCH QUAD 2:1 MUX/DEMUX
INDUSTRIAL TEMPERATURE RANGE
R
ON
(ohms)
V
IN
(Volts)
TYPICAL ON RESISTANCE vs V
IN
AT V
CC
= 5V
Symbol
Parameter
Test Conditions
Min.
Typ.
(1)
Max.
Unit
V
IH
Input HIGH Level
Guaranteed Logic HIGH for Control Pins
2
--
--
V
V
IL
Input LOW Level
Guaranteed Logic LOW for Control Pins
--
--
0.8
V
I
IN
Input LeakageCurrent (Control Inputs)
(2)
0V
V
IN
V
CC
--
--
1
A
I
OZ
Off-State Output Current (Hi-Z)
0V
V
OUT
V
CC
--
--
1
A
R
ON
Switch ON Resistance
V
CC
= Min., V
IN
= 0V, I
ON
= 30mA
--
5
7
V
CC
= Min., V
IN
= 2.4V, I
ON
=15mA
--
10
15
V
P
Pass Voltage
(2)
V
IN
= V
CC
= 5V, I
OUT
= -5
A
3.7
4
4.2
V
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= 40C to +85C, V
CC
= 5.0V 5%
NOTES:
1. Typical values are at V
CC
= 5.0V, T
A
= 25C.
2. Pass Voltage is guaranteed but not production tested.
16
14
12
10
8
6
4
2
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4
INDUSTRIAL TEMPERATURE RANGE
IDTQS3257
HIGH-SPEED CMOS QUICKSWITCH QUAD 2:1 MUX/DEMUX
POWER SUPPLY CHARACTERISTICS
Symbol
Parameter
Test Conditions
(1)
Max.
Unit
I
CCQ
Quiescent Power Supply Current
V
CC
= Max., V
IN
= GND or Vcc, f = 0
3
A
I
CC
Power Supply Current per Control Input HIGH
(2)
V
CC
= Max., V
IN
= 3.4V, f = 0
1.5
mA
I
CCD
Dynamic Power Supply Current per MHz
(3)
V
CC
= 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 (V
IN
= 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
T
A
= -40C to +85C, V
CC
= 5.0V 5%;
C
LOAD
= 50pF, R
LOAD
= 500
unless otherwise noted.
Symbol
Parameter
Min.
(1)
Typ.
Max.
Unit
t
PLH
Data Propagation Delay
(2,3)
--
--
0.25
(3)
ns
t
PHL
Ix to Y
t
PZH
Switch Turn-on Delay
0.5
--
5.2
ns
t
PZL
Sx to Y
t
PZH
Switch Turn-on Delay
0.5
--
4.8
ns
t
PZL
Ex to Y
t
PHZ
Switch Turn-off Delay
(2)
0.5
--
5
ns
t
PLZ
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 C
L
= 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
SO
Q
S1
3257
High Speed CMOS Quickswitch Quad 2:1 Mux/Demux
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