The UT54ACS264 and the UT54ACTS264 are look-ahead gen-
erators designed specifically to perform a carry-anticipate across
any number of n-bit counters, thus increasing system clock fre-
quency. A carry enable CE, and carry outputs RCOA and RCOB
are provided for n-bit cascading.
Use the counter with either active-high-carry or active-low-car-
ry counters. For active-high-carry counters, CE is active high,
the A set of inputs and output RCOA are used. The B set of
inputs are connected to a low logic level. For active-low-carry
counters, CE is active low, the B set of inputs and output RCOB
are used. The A set of inputs are connected to a high logic level.
The devices are characterized over full military temperature
range of -55°C to +125°C.
PINOUTS
16-Pin DIP
Top View
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
A1
B1
A0
B0
A3
B3
RCOB
V
SS
V
DD
B2
A2
CE
C0
C1
RCOA
C2
16-Lead Flatpack
Top View
A1
B1
A0
B0
A3
B3
RCOB
V
SS
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
DD
B2
A2
CE
C0
C1
RCOA
C2
1
LOGIC SYMBOL
ACTIVE-HIGH INPUTS
ACTIVE-LOW INPUTS
CE
B0
A0
B1
A1
B2
A2
B3
A3
(13)
(4)
(3)
(2)
(1)
(15)
(14)
(6)
(5)
Z1
Z2
G3
Z4
G5
Z6
G7
Z8
G9
1,3
2,3
1,3,5
2,3,5
4,5
1,3,5,7
2,3,5,7
4,5,7
6,7
1,3,5,7,
4,5,7,9
6,7,9
8,9
1
2
4
6
8
≥1
≥1
(12)
CE
C0
B0
(13)
(4)
(3)
(2)
(1)
(15)
(14)
(6)
(5)
Z1
G2
Z3
G4
Z5
G6
Z7
G8
Z9
1,2
3
5
3,4
1,2,4
7
5,6
3,4,6
1,2,4,6
9
7,8
5,6,8
3,4,6,8
1,4,6,8
≥1
≥1
(12)
C0
(11)
(11)
C1
A0
B1
C1
≥1
(9)
C2
≥1
(9)
C2
A1
B2
≥1
(10)
RCOA
≥1
(10)
RCOA
A2
B3
A3
(7)
RCOB
≥1
1,2,4,6,8
(7)
RCOB
Notes:
1. Logic symbols in accordance with ANSI/IEEE Std 91-1984 and IEC
Publication 617-12.
FUNCTION TABLE FOR C2 OUTPUT
INPUTS
A2
H
H
H
H
L
X
X
X
A1
X
H
H
H
X
L
X
X
A0
X
X
H
H
X
X
L
X
B2
H
X
X
X
X
L
L
L
B1
X
H
X
X
X
X
L
L
B0
X
X
H
X
X
X
X
L
CE
X
X
X
H
X
X
X
L
OUTPUT
C2
H
H
H
H
L
L
L
L
FUNCTION TABLE FOR C0 OUTPUT
INPUTS
A0
H
H
L
X
B0
H
X
X
L
CE
X
H
X
L
OUTPUT
C0
H
H
L
L
FUNCTION TABLE FOR C1 OUTPUT
INPUTS
A1
H
H
H
L
X
X
A0
X
H
H
X
L
X
B1
H
X
X
X
L
L
B0
X
H
X
X
X
L
CE
X
X
H
X
X
L
OUTPUT
C1
H
H
H
L
L
L
FUNCTION TABLE FOR RCOA OUTPUT
INPUTS
A3
H
H
H
H
L
X
X
X
X
A2
X
H
H
H
X
L
X
X
X
A1
X
X
H
H
X
X
L
X
X
A0
X
X
X
H
X
X
X
L
X
B3
H
X
X
X
X
L
L
L
L
B2
X
H
X
X
X
X
L
L
L
B1
X
X
H
X
X
X
X
L
L
CE
X
X
X
H
X
X
X
X
L
OUTPUT
RCOA
H
H
H
H
L
L
L
L
L
FUNCTION TABLE FOR RCOB OUTPUT
INPUTS
B3
H
X
X
X
X
L
B2
X
H
X
X
X
L
B1
X
X
H
X
X
L
B0
X
X
X
H
X
L
CE
X
X
X
X
H
L
OUTPUT
RCOB
H
H
H
H
H
L
2
LOGIC DIAGRAM
(7)
(13)
CE
RCOB
(10)
RCOA
B3
A3
(6)
(5)
(9)
C2
B2
A2
(15)
(14)
(11)
C1
B1
A1
(2)
(1)
(12)
B0
A0
(4)
(3)
C0
3
OPERATIONAL ENVIRONMENT
1
PARAMETER
Total Dose
SEU Threshold
2
SEL Threshold
Neutron Fluence
LIMIT
1.0E6
80
120
1.0E14
UNITS
rads(Si)
MeV-cm
2
/mg
MeV-cm
2
/mg
n/cm
2
Notes:
1. Logic will not latchup during radiation exposure within the limits defined in the table.
2. Device storage elements are immune to SEU affects.
ABSOLUTE MAXIMUM RATINGS
SYMBOL
V
DD
V
I/O
T
STG
T
J
T
LS
Θ
JC
I
I
P
D
PARAMETER
Supply voltage
Voltage any pin
Storage Temperature range
Maximum junction temperature
Lead temperature (soldering 5 seconds)
Thermal resistance junction to case
DC input current
Maximum power dissipation
LIMIT
-0.3 to 7.0
-.3 to V
DD
+.3
-65 to +150
+175
+300
20
±10
1
UNITS
V
V
°C
°C
°C
°C/W
mA
W
Note:
1. Stresses outside the listed absolute maximum ratings may cause permanent damage to the device. This is a stress rating only, functional operation of the device at
these or any other conditions beyond limits indicated in the operational sections is not recommended. Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
RECOMMENDED OPERATING CONDITIONS
SYMBOL
V
DD
V
IN
T
C
PARAMETER
Supply voltage
Input voltage any pin
Temperature range
LIMIT
4.5 to 5.5
0 to V
DD
-55 to + 125
UNITS
V
V
°C
4
DC ELECTRICAL CHARACTERISTICS
7
(V
DD
= 5.0V
±
10%; V
SS
= 0V
6
, -55°C < T
C
< +125°C); Unless otherwise noted, Tc is per the temperature range ordered.
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