FAST CMOS 20-BIT
TRANSPARENT
LATCHES
Integrated Device Technology, Inc.
IDT54/74FCT16841AT/BT/CT/ET
IDT54/74FCT162841AT/BT/CT/ET
FEATURES:
• Common features:
– 0.5 MICRON CMOS Technology
– High-speed, low-power CMOS replacement for
ABT functions
–
Typical t
SK
(o) (Output Skew) < 250ps
– Low input and output leakage
≤1µA
(max.)
– ESD > 2000V per MIL-STD-883, Method 3015;
> 200V using machine model (C = 200pF, R = 0)
– Packages include 25 mil pitch SSOP, 19.6 mil pitch
TSSOP, 15.7 mil pitch TVSOP and 25 mil pitch Cerpack
– Extended commercial range of -40°C to +85°C
– V
CC
= 5V
±10%
• Features for FCT16841AT/BT/CT/ET:
– High drive outputs (-32mA I
OH
, 64mA I
OL
)
– Power off disable outputs permit “live insertion”
– Typical V
OLP
(Output Ground Bounce) < 1.0V at
V
CC
= 5V, T
A
= 25°C
• Features for FCT162841AT/BT/CT/ET:
– Balanced Output Drivers:
±24mA
(commercial),
±16mA
(military)
– Reduced system switching noise
– Typical V
OLP
(Output Ground Bounce) < 0.6V at
V
CC
= 5V,T
A
= 25°C
DESCRIPTION:
The FCT16841AT/BT/CT/ET and FCT162841AT/BT/CT/
ET 20-bit transparent D-type latches are built using advanced
dual metal CMOS technology. These high-speed, low-power
latches are ideal for temporary storage of data. They can be
used for implementing memory address latches, I/O ports,
and bus drivers. The Output Enable and Latch Enable controls
are organized to operate each device as two 10-bit latches or
one 20-bit latch. Flow-through organization of signal pins
simplifies layout. All inputs are designed with hysteresis for
improved noise margin.
The FCT16841AT/BT/CT/ET are ideally suited for driving
high-capacitance loads and low-impedance backplanes. The
output buffers are designed with power off disable capability
to allow "live insertion" of boards when used as backplane
drivers.
The FCT162841AT/BT/CT/ET have balanced output drive
with current limiting resistors. This offers low ground bounce,
minimal undershoot, and controlled output fall times–reducing
the need for external series terminating resistors. The
FCT162841AT/BT/CT/ET are plug-in replacements for the
FCT16841AT/BT/CT/ET and ABT16841 for on-board inter-
face applications.
FUNCTIONAL BLOCK DIAGRAM
1
OE
2
OE
1
LE
1
D
1
2
LE
D
1
Q
1
2
D
1
D
2
Q
1
C
C
TO 9 OTHER CHANNELS
2556 drw 01
TO 9 OTHER CHANNELS
2556 drw 02
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
MILITARY AND COMMERCIAL TEMPERATURE RANGES
©1996
Integrated Device Technology, Inc.
JULY 1996
DSC-2556/7
5.18
1
IDT54/74FCT16841AT/BT/CT/ET, 162841AT/BT/CT/ET
FAST CMOS 20-BIT TRANSPARENT LATCHES
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN CONFIGURATIONS
1
OE
1
Q
1
1
Q
2
1
2
3
4
5
6
7
8
9
10
11
12
13
56
55
54
53
52
51
50
49
48
47
46
45
44
1
LE
1
D
1
1
D
2
1
OE
1
Q
1
1
Q
2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
CERPACK
TOP VIEW
E56-1
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
2556 drw 04
1
LE
1
D
1
1
D
2
GND
1
Q
3
1
Q
4
GND
1
D
3
1
D
4
GND
1
Q
3
1
Q
4
GND
1
D
3
1
D
4
V
CC
1
Q
5
1
Q
6
1
Q
7
V
CC
1
D
5
1
D
6
1
D
7
V
CC
1
Q
5
1
Q
6
1
Q
7
V
CC
1
D
5
1
D
6
1
D
7
GND
1
Q
8
1
Q
9
1
Q
10
2
Q
1
2
Q
2
2
Q
3
GND
1
D
8
1
D
9
1
D
10
2
D
1
2
D
2
2
D
3
GND
1
Q
8
1
Q
9
1
Q
10
2
Q
1
2
Q
2
2
Q
3
GND
1
D
8
1
D
9
1
D
10
2
D
1
2
D
2
2
D
3
14 SO56-1 43
SO56-2
15 SO56-3 42
16
17
18
19
20
21
22
23
24
25
26
27
28
41
40
39
38
37
36
35
34
33
32
31
30
29
GND
2
Q
4
2
Q
5
2
Q
6
GND
2
D
4
2
D
5
2
D
6
GND
2
Q
4
2
Q
5
2
Q
6
GND
2
D
4
2
D
5
2
D
6
V
CC
2
Q
7
2
Q
8
V
CC
2
D
7
2
D
8
V
CC
2
Q
7
2
Q
8
V
CC
2
D
7
2
D
8
GND
2
Q
9
2
Q
10
2
OE
GND
2
D
9
2
D
10
2
LE
2556 drw 03
GND
2
Q
9
2
Q
10
2
OE
GND
2
D
9
2
D
10
2
LE
SSOP/
TSSOP/TVSOP
TOP VIEW
5.18
2
IDT54/74FCT16841AT/BT/CT/ET, 162841AT/BT/CT/ET
FAST CMOS 20-BIT TRANSPARENT LATCHES
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN DESCRIPTION
Pin Names
xDx
xLE
x
OE
xQx
Description
Data Inputs
Latch Enable Input (Active HIGH)
Output Enable Input (Active LOW)
3-State Outputs
2556 tbl 01
FUNCTION TABLE
(1)
xDx
H
L
X
X
Inputs
xLE
H
H
L
X
x
OE
L
L
L
H
Outputs
xQx
H
L
Q
(2)
Z
2556 tbl 02
NOTES:
1. H = HIGH Voltage Level
L = LOW Voltage Level
X = Don’t Care
Z = High Impedance
2. Output level before xLE HIGH-to-LOW Transition.
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
Description
Max.
V
TERM(2)
Terminal Voltage with Respect to –0.5 to +7.0
GND
V
TERM(3)
Terminal Voltage with Respect to
–0.5 to
GND
V
CC
+0.5
T
STG
Storage Temperature
–65 to +150
I
OUT
DC Output Current
–60 to +120
Unit
V
V
°C
mA
CAPACITANCE
(T
A
= +25°C, f = 1.0MHz)
Symbol
Parameter
(1)
C
IN
Input
Capacitance
C
OUT
Output
Capacitance
Conditions
V
IN
= 0V
V
OUT
= 0V
Typ.
3.5
3.5
Max. Unit
6.0
pF
8.0
pF
2556 lnk 04
NOTE:
1. This parameter is measured at characterization but not tested.
2556 lnk 03
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RAT-
INGS 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. All device terminals except FCT162XXXT Output and I/O terminals.
3. Output and I/O terminals for FCT162XXXT.
5.18
3
IDT54/74FCT16841AT/BT/CT/ET, 162841AT/BT/CT/ET
FAST CMOS 20-BIT TRANSPARENT LATCHES
MILITARY AND COMMERCIAL TEMPERATURE RANGES
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Commercial: T
A
= –40°C to +85°C, V
CC
= 5.0V
±
10%; Military: T
A
= –55°C to +125°C, V
CC
= 5.0V
±
10%
Symbol
V
IH
V
IL
I
I H
I
I L
I
OZH
I
OZL
V
IK
I
OS
V
H
I
CCL
I
CCH
I
CCZ
Parameter
Input HIGH Level
Input LOW Level
Input HIGH Current (Input pins)
(5)
Input HIGH Current (I/O pins)
(5)
Input LOW Current (Input pins)
(5)
Input LOW Current (I/O pins)
(5)
High Impedance Output Current
(3-State Output pins)
(5)
Clamp Diode Voltage
Short Circuit Current
Input Hysteresis
Quiescent Power Supply Current
V
CC
= Min., I
IN
= –18mA
V
CC
= Max., V
O
= GND
(3)
—
Test Conditions
(1)
Guaranteed Logic HIGH Level
Guaranteed Logic LOW Level
V
CC
= Max.
V
I
= V
CC
V
I
= GND
V
CC
= Max.
V
O
= 2.7V
V
O
= 0.5V
Min.
2.0
—
—
—
—
—
—
—
—
–80
—
—
Typ.
(2)
—
—
—
—
—
—
—
—
–
0.7
–
140
Max.
—
Unit
V
V
µA
0.8
±1
±1
±1
±1
±1
±1
–
1.2
–
225
—
µA
V
mA
mV
µA
100
5
V
CC
= Max., V
IN
= GND or V
CC
500
2556 lnk 05
OUTPUT DRIVE CHARACTERISTICS FOR FCT16841T
Symbol
I
O
V
OH
Parameter
Output Drive Current
Output HIGH Voltage
Test Conditions
(1)
V
CC
= Max., V
O
= 2.5V
(3)
V
CC
= Min.
V
IN
= V
IH
or V
IL
I
OH
= –3mA
I
OH
= –12mA MIL.
I
OH
= –15mA COM'L.
I
OH
= –24mA MIL.
I
OH
= –32mA COM'L.
(4)
I
OL
= 48mA MIL.
I
OL
= 64mA COM'L.
≤
4.5V
Min.
–50
2.5
2.4
2.0
—
—
Typ.
(2)
—
Max.
–
180
—
—
—
0.55
±1
Unit
mA
V
V
V
V
µA
2556 lnk 06
3.5
3.5
3.0
0.2
—
V
OL
I
OFF
Output LOW Voltage
Input/Output Power Off Leakage
(5)
V
CC
= Min.
V
IN
= V
IH
or V
IL
V
CC
= 0V, V
IN
or V
O
OUTPUT DRIVE CHARACTERISTICS FOR FCT162841T
Symbol
I
ODL
I
ODH
V
OH
V
OL
Parameter
Output LOW Current
Output HIGH Current
Output HIGH Voltage
Output LOW Voltage
Test Conditions
(1)
V
CC
= 5V, V
IN
= V
IH
or V
IL,
V
OUT
= 1.5V
(3)
V
CC
= 5V, V
IN
= V
IH
or V
IL,
V
OUT
= 1.5V
(3)
V
CC
= Min.
V
IN
= V
IH
or V
IL
V
CC
= Min.
V
IN
= V
IH
or V
IL
I
OH
= –16mA MIL.
I
OH
= –24mA COM'L.
I
OL
= 16mA MIL.
I
OL
= 24mA COM'L.
Min.
60
–60
2.4
—
Typ.
(2)
115
–115
3.3
0.3
Max.
200
–200
—
0.55
Unit
mA
mA
V
V
2556 lnk 07
NOTES:
1. For conditions shown as Max. or Min., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at Vcc = 5.0V, +25°C ambient.
3. Not more than one output should be tested at one time. Duration of the test should not exceed one second.
4. Duration of the condition can not exceed one second.
5. The test limit for this parameter is
±
5µA at T
A
= –55°C.
5.18
4
IDT54/74FCT16841AT/BT/CT/ET, 162841AT/BT/CT/ET
FAST CMOS 20-BIT TRANSPARENT LATCHES
MILITARY AND COMMERCIAL TEMPERATURE RANGES
POWER SUPPLY CHARACTERISTICS
Symbol
∆I
CC
I
CCD
Parameter
Quiescent Power Supply Current
TTL Inputs HIGH
Dynamic Power Supply
Current
(4)
Test Conditions
(1)
V
CC
= Max.
V
IN
= 3.4V
(3)
V
CC
= Max.
Outputs Open
x
OE
= GND
One Input Toggling
50% Duty Cycle
V
CC
= Max.
Outputs Open
fi =10MHz
50% Duty Cycle
x
OE
= GND
xLE
=
V
CC
One Bit Toggling
V
CC
= Max.
Outputs Open
fi = 2.5MHz
50% Duty Cycle
x
OE
= GND
xLE = V
CC
Twenty Bits Toggling
V
IN
= V
CC
V
IN
= GND
Min.
—
—
Typ.
(2)
0.5
60
Max.
1.5
100
Unit
mA
µA/
MHz
I
C
Total Power Supply Current
(6)
V
IN
= V
CC
V
IN
= GND
V
IN
= 3.4V
V
IN
= GND
—
0.6
1.5
mA
—
0.9
2.3
V
IN
= V
CC
V
IN
= GND
V
IN
= 3.4V
V
IN
= GND
—
3.0
5.5
(5)
—
8.0
20.5
(5)
NOTES:
1. For conditions shown as Max. or Min., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25°C ambient.
3. Per TTL driven input (V
IN
= 3.4V). All other inputs at V
CC
or GND.
4. This parameter is not directly testable, but is derived for use in Total Power Supply Calculations.
5. Values for these conditions are examples of the I
CC
formula. These limits are guaranteed but not tested.
6. I
C
= I
QUIESCENT
+ I
INPUTS
+ I
DYNAMIC
I
C
= I
CC
+
∆I
CC
D
H
N
T
+ I
CCD
(f
CP
N
CP
/2 + f
i
N
i
)
I
CC
= Quiescent Current (I
CCL
,
I
CCH
and I
CCZ
)
∆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 Input Transition Pair (HLH or LHL)
f
CP
= Clock Frequency for Register Devices (Zero for Non-Register Devices)
N
CP
= Number of Clock Inputs at f
CP
f
i
= Input Frequency
N
i
= Number of Inputs at f
i
2556 tbl 08
5.18
5
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