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IDTQS74FCT2541T/AT/CT
HIGH-SPEED CMOS 8-INPUT BUFFER/LINE DRIVER
INDUSTRIAL TEMPERATURE RANGE
DECEMBER 2000
2000 Integrated Device Technology, Inc.
DSC-5250/3
c
IDTQS74FCT2541T/AT/CT
INDUSTRIAL TEMPERATURE RANGE
FUNCTIONAL BLOCK DIAGRAM
FEATURES:
CMOS power levels: <7.5mW static
Undershoot clamp diodes on all outputs
True TTL input and output compatibility
Ground bounce controlled outputs
Reduced output swing of 0 to 3.5V
Built-in 25
series resistor outputs reduce reflection and other
system noise
Std., A and C speed grades with 4.1ns t
PD
for C
I
OL
= 12mA
Available in SOIC and QSOP packages
HIGH-SPEED CMOS
8-INPUT BUFFER/LINE
DRIVER
DESCRIPTION:
The IDTQS74FCT2541T is an 8-bit buffer/line driver with 3-state
outputs and a 25
resistor output , ideal for driving transmission lines and
reducing system noise. The 2540 series parts can replace the 540 series
to reduce noise in an existing design. All inputs have clamp diodes for
undershoot noise suppression. All outputs have ground bounce suppres-
sion. Outputs will not load an active bus when Vcc is removed from the
device.
A
0
A
1
A
2
A
3
2
3
4
5
Y
1
Y
2
Y
3
Y
0
18
17
16
15
6
7
8
9
A
4
A
5
A
6
A
7
14
13
12
11
Y
5
Y
6
Y
7
Y
4
O E1
OE2
2
INDUSTRIAL TEMPERATURE RANGE
IDTQS74FCT2541T/AT/CT
HIGH-SPEED CMOS 8-INPUT BUFFER/LINE DRIVER
SOIC/ QSOP
TOP VIEW
PIN CONFIGURATION
Symbol
Description
Max
Unit
V
TERM
Terminal Voltage with Respect to GND
0.5 to +7
V
T
STG
Storage Temperature
65 to +150
C
I
OUT
DC Output Current Max Sink Current/Pin
120
mA
I
IK
Input Diode Current, V
IN
< 0
20
mA
I
OK
Output Diode Current, V
OUT
< 0
50
mA
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.
Symbol
Parameter
(1)
Conditions
Typ.
Max.
Unit
C
IN
Input Capacitance
V
IN
= 0V
4
--
pF
C
OUT
Output Capacitance
V
OUT
= 0V
8
--
pF
CAPACITANCE
(T
A
= +25C, F = 1.0MHz)
NOTE:
1. This parameter is measured at characterization but not tested.
2
3
1
A
1
V
CC
16
15
14
Y
4
Y
3
Y
5
Y
1
Y
2
11
Y
7
Y
6
Y
0
19
18
20
17
13
12
OE
1
5
6
A
6
7
A
4
A
5
4
A
2
A
3
SO20-2
SO20-8
8
9
GND
10
A
7
A
0
OE
2
FUNCTION TABLE
(1)
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
X = Don't Care
Z = High-Impedance
OE1
OE2
A Inputs
Y Outputs
Function
H
X
X
Z
Disable Outputs
X
H
X
Z
L
L
L
L
Enable Outputs
L
L
H
H
PIN DESCRIPTION
Pin Names
I/O
Description
A x
I
Data Inputs
Y x
O
Data Outputs
OE1, OE2
I
3-State Output Enable (Active LOW)
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IDTQS74FCT2541T/AT/CT
HIGH-SPEED CMOS 8-INPUT BUFFER/LINE DRIVER
INDUSTRIAL TEMPERATURE RANGE
Symbol
Parameter
Test Conditions
Min.
Typ.
(1)
Max.
Unit
V
IH
Input HIGH Level
Guaranteed Logic HIGH Level
2
--
--
V
V
IL
Input LOW Level
Guaranteed Logic LOW Level
--
--
0.8
V
V
T
Input Hysteresis
V
TLH
- V
THL
for all inputs
--
0.2
--
V
I
IH
Input HIGH Current
V
CC
= Max.
0
V
IN
V
CC
--
--
5
A
I
IL
Input LOW Current
I
OZ
Off-State Output Current (Hi-Z)
V
CC
= Max
0
V
IN
V
CC
--
--
5
A
I
OR
Current Drive
V
CC
= Max., V
OUT
= 2V
(2)
50
--
--
mA
V
IC
Input Clamp Voltage
V
CC
= Min, I
IN
= -18mA , T
A
= 25C
(2)
--
0.7
1.2
V
V
OH
Output HIGH Voltage
V
CC
= Min.
I
OH
= -15mA
2.4
--
--
V
V
OL
Output LOW Voltage
V
CC
= Min.
I
OL
= 12mA
--
--
0.5
V
R
OUT
Output Resistance
V
CC
= Min.
I
OL
= 12mA
20
28
40
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. This parameter is guaranteed but not tested.
POWER SUPPLY CHARACTERISTICS
Following Conditions Apply Unless Otherwise Specified:
Industrial:
T
A
= -40C to +85C, V
CC
= 5.0V 5%
Symbol
Parameter
Test Conditions
(1)
Min.
Max.
Unit
I
CC
Quiescent Power Supply Current
V
CC
= Max.
--
1.5
mA
freq = 0
0V
V
IN
0.2V or
V
CC
- 0.2V
V
IN
Vcc
I
CC
Supply Current per Input TTL Inputs HIGH
V
CC
= Max.
--
2
mA
V
IN
= 3.4V
(2)
freq = 0
I
CCD
Supply Current per Input per MHz
V
CC
= Max.
--
0.25
mA/MHz
Outputs Open and Enabled
One Bit Toggling
50% Duty Cycle
Other inputs at GND or Vcc
(3,4)
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).
3. For flip-flops, I
CCD
is measured by switching one of the data input pins so that the output changes every clock cycle. This is a measurement of device power consumption
only and does not include power to drive load capacitance or tester capacitance.
4. I
C
= I
QUIESCENT
+ I
INPUTS
+ I
DYNAMIC
I
C
= I
CC
+
I
CC
D
H
N
T
+ I
CCD
(f
CP
/2 + f
i
N
i
)
I
CC
= Quiescent Current
I
CC
= Power Supply Current for a TTL High Input (V
IN
= 3.4V)
D
H
= Duty Cycle for TTL Inputs High
N
T
= Number of TTL Inputs at D
H
I
CCD
= Dynamic Current Caused by an Output Transition Pair (HLH or LHL)
f
CP
= Clock Frequency for Register Devices (Zero for Non-Register Devices)
f
i
= Input Frequency
N
i
= Number of Inputs at f
i
All currents are in milliamps and all frequencies are in megahertz.
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INDUSTRIAL TEMPERATURE RANGE
IDTQS74FCT2541T/AT/CT
HIGH-SPEED CMOS 8-INPUT BUFFER/LINE DRIVER
FCT2541T
FCT2541AT
FCT2541CT
Symbol
Parameter
(2)
Min.
Max.
Min.
Max.
Min.
Max.
Unit
t
PLH
Propagation Delay
2
8
2
4.8
2
4.1
ns
t
PHL
Ax to Yx
t
PZH
Output Enable
1.5
10
1.5
6.2
1.5
5.8
ns
t
PZL
OE
to Yx
t
PLZ
Disable Time
(3)
1.5
9.5
1.5
5.6
1.5
5.2
ns
t
PHZ
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
(1)
NOTES:
1. C
LOAD
= 50pF, R
LOAD
= 500
unless otherwise noted.
2. Minimums guaranteed but not tested.
3. This parameter is guaranteed by design but not tested.
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IDTQS74FCT2541T/AT/CT
HIGH-SPEED CMOS 8-INPUT BUFFER/LINE DRIVER
INDUSTRIAL TEMPERATURE RANGE
Pulse
Generator
R
T
D.U.T.
V
CC
V
IN
C
L
V
OUT
50pF
500
500
7.0V
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
DATA
INPUT
TIMING
INPUT
ASYNCHRONOUS CONTROL
PRESET
CLEAR
ETC.
SYNCHRONOUS CONTROL
t
SU
t
H
t
REM
t
SU
t
H
HIGH-LOW-HIGH
PULSE
LOW-HIGH-LOW
PULSE
t
W
1.5V
1.5V
SAME PHASE
INPUT TRANSITION
3V
1.5V
0V
1.5V
V
OH
t
PLH
OUTPUT
OPPOSITE PHASE
INPUT TRANSITION
3V
1.5V
0V
t
PLH
t
PHL
t
PHL
V
OL
CONTROL
INPUT
3V
1.5V
0V
3.5V
0V
OUTPUT
NORMALLY
LOW
OUTPUT
NORMALLY
HIGH
SWITCH
CLOSED
SWITCH
OPEN
V
OL
0.3V
0.3V
t
PLZ
t
PZL
t
PZH
t
PHZ
3.5V
0V
1.5V
1.5V
ENABLE
DISABLE
V
OH
PRESET
CLEAR
CLOCK ENABLE
ETC.
FCTL link
FCTL link
FCTL link
FCTL link
FCTL link
TEST CIRCUITS AND WAVEFORMS
Propagation Delay
Enable and Disable Times
Set-Up, Hold, and Release Times
Pulse Width
NOTES:
1. Diagram shown for input Control Enable-LOW and input Control Disable-HIGH.
2. Pulse Generator for All Pulses: Rate
1.0MHz; t
F
2.5ns; t
R
2.5ns.
Test
Switch
Open Drain
Disable Low
Closed
Enable Low
All Other Tests
Open
SWITCH POSITION
DEFINITIONS:
C
L
= Load capacitance: includes jig and probe capacitance.
R
T
= Termination resistance: should be equal to Z
OUT
of the Pulse Generator.
Test Circuits for All Outputs
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INDUSTRIAL TEMPERATURE RANGE
IDTQS74FCT2541T/AT/CT
HIGH-SPEED CMOS 8-INPUT BUFFER/LINE DRIVER
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
High-Speed CMOS 8-Bit Buffer/Line Driver
2541T
2541AT
2541CT
74
40C to +85C
SO
Q
Small Outline IC (gull wing) (SO20-2)
Quarter Size Small Outline Package (SO20-8)
IDTQS
XX
FCT
XXXX
XX
Package
Device Type
Temp. Range
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