Integrated Device Technology, Inc.
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 timesreducing
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.
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
FAST CMOS 20-BIT
TRANSPARENT
LATCHES
IDT54/74FCT16841AT/BT/CT/ET
IDT54/74FCT162841AT/BT/CT/ET
FUNCTIONAL BLOCK DIAGRAM
2
Q
1
2
OE
2
LE
2
D
1
2556 drw 02
TO 9 OTHER CHANNELS
C
D
1
OE
1
LE
1
Q
1
1
D
1
2556 drw 01
TO 9 OTHER CHANNELS
C
D
MILITARY AND COMMERCIAL TEMPERATURE RANGES
JULY 1996
1996 Integrated Device Technology, Inc.
5.18
DSC-2556/7
1
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
1
A (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
5.18
2
IDT54/74FCT16841AT/BT/CT/ET, 162841AT/BT/CT/ET
FAST CMOS 20-BIT TRANSPARENT LATCHES
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN CONFIGURATIONS
1
Q
1
GND
1
Q
3
V
CC
1
OE
GND
1
Q
10
GND
V
CC
1
Q
2
1
Q
4
1
Q
5
1
Q
6
1
Q
7
1
Q
8
1
Q
9
2
Q
1
2
Q
2
2
Q
3
2
Q
5
2
Q
6
2
Q
4
1
LE
1
D
1
1
D
2
GND
1
D
3
1
D
4
V
CC
1
D
5
1
D
6
1
D
7
1
D
8
1
D
9
1
D
10
2
D
2
GND
GND
47
37
38
39
40
41
42
43
44
45
46
33
34
35
36
56
55
49
50
51
52
53
54
48
1
2
3
4
5
6
7
8
9
10
12
13
14
15
16
17
18
19
20
11
21
22
23
24
2556 drw 04
CERPACK
TOP VIEW
E56-1
GND
2
Q
7
2
Q
8
2
OE
25
26
27
28
2
D
4
V
CC
2
D
5
2
D
6
GND
2
D
7
2
D
8
2
D
9
2
D
10
2
LE
29
30
31
32
2
Q
9
2
Q
10
2
D
1
2
D
3
1
Q
1
GND
1
Q
3
V
CC
1
OE
GND
1
Q
10
GND
1
Q
2
1
Q
4
1
Q
5
1
Q
6
1
Q
7
1
Q
8
1
Q
9
2
Q
3
V
CC
GND
2
Q
4
2
Q
5
2
Q
7
2
Q
8
2
Q
6
2
OE
1
LE
1
D
1
1
D
2
GND
1
D
3
1
D
4
V
CC
1
D
5
1
D
6
1
D
7
1
D
8
1
D
9
1
D
10
GND
GND
2556 drw 03
47
37
38
39
40
41
42
43
44
45
46
33
34
35
36
56
55
49
50
51
52
53
54
48
1
2
3
4
5
6
7
8
9
10
12
13
14
15
16
17
18
19
20
11
21
22
23
24
SSOP/
TSSOP/TVSOP
TOP VIEW
SO56-1
SO56-2
SO56-3
2
Q
1
2
Q
2
2
Q
10
2
Q
9
2
D
3
2
D
4
V
CC
2
D
5
2
D
7
2
D
8
2
D
6
GND
2
D
9
2
D
10
2
LE
29
30
31
32
25
26
27
28
2
D
1
2
D
2
IDT54/74FCT16841AT/BT/CT/ET, 162841AT/BT/CT/ET
FAST CMOS 20-BIT TRANSPARENT LATCHES
MILITARY AND COMMERCIAL TEMPERATURE RANGES
5.18
3
PIN DESCRIPTION
2556 tbl 01
ABSOLUTE MAXIMUM RATINGS
(1)
FUNCTION TABLE
(1)
CAPACITANCE
(T
A
= +25
C, f = 1.0MHz)
2556 lnk 04
NOTES:
2556 tbl 02
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.
NOTE:
1. This parameter is measured at characterization but not tested.
Symbol
Parameter
(1)
Conditions
Typ.
Max.
Unit
C
IN
Input
Capacitance
V
IN
= 0V
3.5
6.0
pF
C
OUT
Output
Capacitance
V
OUT
= 0V
3.5
8.0
pF
Pin Names
Description
xDx
Data Inputs
xLE
Latch Enable Input (Active HIGH)
x
OE
Output Enable Input (Active LOW)
xQx
3-State Outputs
Inputs
Outputs
xDx
xLE
x
OE
OE
xQx
H
H
L
H
L
H
L
L
X
L
L
Q
(2)
X
X
H
Z
Symbol
Description
Max.
Unit
V
TERM(2)
Terminal Voltage with Respect to
GND
0.5 to +7.0
V
V
TERM(3)
Terminal Voltage with Respect to
GND
0.5 to
V
CC
+0.5
V
T
STG
Storage Temperature
65 to +150
C
I
OUT
DC Output Current
60 to +120 mA
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.
2556 lnk 03
5.18
4
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
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
V
IH
Input HIGH Level
Guaranteed Logic HIGH Level
2.0
--
--
V
V
IL
Input LOW Level
Guaranteed Logic LOW Level
--
--
0.8
V
I
I H
Input HIGH Current (Input pins)
(5)
V
CC
= Max.
V
I
= V
CC
--
--
1
A
Input HIGH Current (I/O pins)
(5)
--
--
1
I
I L
Input LOW Current (Input pins)
(5)
V
I
= GND
--
--
1
Input LOW Current (I/O pins)
(5)
--
--
1
I
OZH
High Impedance Output Current
V
CC
= Max.
V
O
= 2.7V
--
--
1
A
I
OZL
(3-State Output pins)
(5)
V
O
= 0.5V
--
--
1
V
IK
Clamp Diode Voltage
V
CC
= Min., I
IN
= 18mA
--
0.7
1.2
V
I
OS
Short Circuit Current
V
CC
= Max., V
O
= GND
(3)
80
140
225
mA
V
H
Input Hysteresis
--
--
100
--
mV
I
CCL
I
CCH
I
CCZ
Quiescent Power Supply Current
V
CC
= Max., V
IN
= GND or V
CC
--
5
500
A
2556 lnk 05
OUTPUT DRIVE CHARACTERISTICS FOR FCT16841T
2556 lnk 06
OUTPUT DRIVE CHARACTERISTICS FOR FCT162841T
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
5
A at T
A
= 55
C.
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
I
ODL
Output LOW Current
V
CC
= 5V, V
IN
= V
IH
or
V
IL,
V
OUT
= 1.5V
(3)
60
115
200
mA
I
ODH
Output HIGH Current
V
CC
= 5V, V
IN
= V
IH
or V
IL,
V
OUT
= 1.5V
(3)
60
115
200
mA
V
OH
Output HIGH Voltage
V
CC
= Min.
V
IN
= V
IH
or V
IL
I
OH
= 16mA MIL.
I
OH
= 24mA COM'L.
2.4
3.3
--
V
V
OL
Output LOW Voltage
V
CC
= Min.
V
IN
= V
IH
or V
IL
I
OL
= 16mA MIL.
I
OL
= 24mA COM'L.
--
0.3
0.55
V
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
I
O
Output Drive Current
V
CC
= Max., V
O
= 2.5V
(3)
50
--
180
mA
V
OH
Output HIGH Voltage
V
CC
= Min.
I
OH
= 3mA
2.5
3.5
--
V
V
IN
= V
IH
or V
IL
I
OH
= 12mA MIL.
I
OH
= 15mA COM'L.
2.4
3.5
--
V
I
OH
= 24mA MIL.
I
OH
= 32mA COM'L.
(4)
2.0
3.0
--
V
V
OL
Output LOW Voltage
V
CC
= Min.
V
IN
= V
IH
or V
IL
I
OL
= 48mA MIL.
I
OL
= 64mA COM'L.
--
0.2
0.55
V
I
OFF
Input/Output Power Off Leakage
(5)
V
CC
= 0V, V
IN
or V
O
4.5V
--
--
1
A
IDT54/74FCT16841AT/BT/CT/ET, 162841AT/BT/CT/ET
FAST CMOS 20-BIT TRANSPARENT LATCHES
MILITARY AND COMMERCIAL TEMPERATURE RANGES
5.18
5
POWER SUPPLY CHARACTERISTICS
2556 tbl 08
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
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
I
CC
Quiescent Power Supply Current
TTL Inputs HIGH
V
CC
= Max.
V
IN
= 3.4V
(3)
--
0.5
1.5
mA
I
CCD
Dynamic Power Supply
Current
(4)
V
CC
= Max.
Outputs Open
x
OE
= GND
One Input Toggling
50% Duty Cycle
V
IN
= V
CC
V
IN
= GND
--
60
100
A/
MHz
I
C
Total Power Supply Current
(6)
V
CC
= Max.
Outputs Open
fi =10MHz
V
IN
= V
CC
V
IN
= GND
--
0.6
1.5
mA
50% Duty Cycle
x
OE
= GND
xLE
=
V
CC
One Bit Toggling
V
IN
= 3.4V
V
IN
= GND
--
0.9
2.3
V
CC
= Max.
Outputs Open
fi = 2.5MHz
V
IN
= V
CC
V
IN
= GND
--
3.0
5.5
(5)
50% Duty Cycle
x
OE
= GND
xLE = V
CC
Twenty Bits Toggling
V
IN
= 3.4V
V
IN
= GND
--
8.0
20.5
(5)
PDF 
ZIP