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IDTQS3244
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
DECEMBER 1999
1999 Integrated Device Technology, Inc.
DSC-5722/2
c
INDUSTRIAL TEMPERATURE RANGE
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
APPLICATIONS:
Hot-swapping, hot-docking
Voltage translation (5V to 3.3V)
Power conservation
Capacitance reduction and isolation
Logic replacement (data processing)
Clock gating
Bus switching and isolation
FUNCTIONAL BLOCK DIAGRAM
FEATURES:
Enhanced N channel FET with no inherent diode to Vcc
25
bidirectional switches connect inputs to outputs
Pin compatible with 74F244, 74FCT244, and 74FCT244T
Zero propagation delay, zero ground bounce
Undershoot clamp diodes on all switch and control inputs
Available in QSOP, SOIC, and TSSOP packages
IDTQS3244
QUICKSWITCH
PRODUCTS
HIGH-SPEED CMOS
QUICKSWITCH
8-BIT BUS SWITCH
DESCRIPTION:
The QS3244 provides a set of eight high-speed CMOS TTL-compatible
bus switches in a pinout compatible with 74FCT244, 74F244, 74ALS/AS/
LS244 8-bit drivers. The low ON resistance (5
) of the 3244 allows inputs
to be connected to outputs without adding propagation delay and without
generating additional ground bounce noise. The two enable (xG) signals
turn the switches on similar to the xG signals of the 74'244.
QuickSwitch devices provide an order of magnitude faster speed than
conventional logic devices.
The QS3244 is characterized for operation at -40C to +85C.
1A
1
1Y
1
1A
2
1Y
2
1A
3
1Y
3
1A
4
1Y
4
1G
2A
1
2Y
1
2A
2
2Y
2
2A
3
2Y
3
2A
4
2Y
4
2G
2
INDUSTRIAL TEMPERATURE RANGE
IDTQS3244
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
PIN CONFIGURATION
QSOP/ SOIC/ TSSOP
TOP VIEW
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)
NOTES:
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. V
CC
terminals.
3. All terminals except V
CC
.
Pin Names
Description
1G, 2G
Output Enable
Ax, Yx
Data I/Os
PIN DESCRIPTION
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
FUNCTION TABLE
(1)
Pins
Typ.
Max.
(1)
Unit
Control Inputs
3
5
pF
Quickswitch Channels (Switch OFF)
5
7
pF
CAPACITANCE
(T
A
= +25C, f = 1MHz, V
IN
= 0V, V
OUT
= 0V)
NOTE:
1. This parameter is guaranteed but not production tested.
1G
2G
1A, 1Y I/Os
2A, 2Y I/Os
H
H
Disconnected
Disconnected
L
H
1Ax = 1Yx
Disconnected
H
L
Disconnected
2Ax = 2Yx
L
L
1Ax = 1Yx
2Ax = 2Yx
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
1G
1A
1
2Y
4
1A
2
2Y
3
1A
3
2Y
2
1A
4
2Y
1
G ND
V
C C
2G
1Y
1
2A
4
1Y
2
2A
3
1Y
3
2A
2
1Y
4
2A
1
3
IDTQS3244
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
Symbol
Parameter
Test Conditions
Min.
Typ.
(1)
Max.
Unit
V
IH
Input HIGH Voltage
Guaranteed Logic HIGH for Control Inputs
2
--
--
V
V
IL
Input LOW Voltage
Guaranteed Logic LOW for Control Inputs
--
--
0.8
V
I
IN
Input Leakage Current (Control Inputs)
0V
V
IN
V
CC
--
--
1
A
I
OZ
Off-State Current (Hi-Z)
0V
V
OUT
V
CC,
Switches OFF
--
--
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
12
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
= 5V 5%
NOTES:
1. Typical values are at V
CC
= 5V and T
A
= 25C.
2. Pass voltage is guaranteed but not production tested.
TYPICAL ON RESISTANCE vs V
IN
AT V
CC
= 5V
R
ON
(ohms)
V
IN
(Volts)
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
IDTQS3244
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
NOTES:
1. For conditions shown as Min. or Max., use the appropriate values specified under DC Electrical Characteristics.
2. Per TTL-driven input (V
IN
= 3.4V, control inputs only). A 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 A and Y inputs generate no significant
AC or DC currents as they transition. This parameter is guaranteed but not production tested.
POWER SUPPLY CHARACTERISTICS
Symbol
Parameter
Test Conditions
(1)
Max.
Unit
I
CCQ
Quiescent Power Supply Current
V
CC
= Max., V
IN
= GND or V
CC
, f = 0
3
A
I
CC
Power Supply Current per Control Input HIGH
(2)
V
CC
= Max., V
IN
= 3.4V, f = 0
2.5
mA
I
CCD
Dynamic Power Supply Current per MHz
(3)
V
CC
= Max., A and Y Pins Open, Control Inputs Toggling @ 50% Duty Cycle
0.25
mA/MHz
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
T
A
= -40C to +85C, V
CC
= 5V 5%
C
LOAD
= 50pF, R
LOAD
= 500
unless otherwise noted.
Symbol
Parameter
Min
.
(1)
Typ.
Max.
Unit
t
PLH
Data Propagation Delay
(2)
0.25
(3)
ns
t
PHL
Ax to Yx
t
PZL
Switch Turn-On Delay
0.5
5.6
ns
t
PZH
1G, 2G to Yx
t
PLZ
Switch Turn-Off Delay
(2)
0.5
5.2
ns
t
PHZ
1G, 2G to Yx
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 at 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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IDTQS3244
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
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
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Package
Device Type
Quarter Size Outline Package
Small Outline IC
Thin Shrink Small Outline Package
Q
SO
PA
3244
High Speed CMOS Quickswitch 8-Bit Bus Switch
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