Philips Semiconductors
Product specification
4-bit full adder with fast carry
FEATURES
•
Adds two decimal numbers
•
Full internal look-ahead
•
Fast ripple carry for economical expansion
•
Output capability: standard driver
•
I
CC
category: MSI
GENERAL DESCRIPTION
The 74HC/HCT583 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JECEC
standard no. 7A.
The 74HC/HCT583 are high-speed 4-bit BCD full adders
with internal carry look-ahead. They accept two 4-bit
decimal numbers (A
0
to A
3
and B
0
to B
3
) and a carry input
(C
IN
).
QUICK REFERENCE DATA
GND = 0 V; T
amb
= 25
°C;
t
r
= t
f
= 6 ns
74HC/HCT583
The “583” generates the decimal sum outputs (∑
0
to
∑
3
)
and a carry output (C
n+4
) if the sum is greater than 9.
If an addition of two BCD numbers produce a number
greater than 9, a valid BCD number and a carry will result.
For input values larger than 9, the number is converted
from binary to BCD. Binary to BCD conversion occurs by
grounding one set of inputs, A
n
or B
n
and applying a 4-bit
binary number to the other set of inputs. If the input is
between 0 and 9, a BCD number occurs at the output.
If the binary input falls between 10 and 15, a carry term is
generated. Both the carry term and the sum are the BCD
equivalent of the binary input. Converting binary numbers
greater than 16 may be achieved by cascading “583s”.
See the “283” for the binary version.
TYPICAL
SYMBOL
t
PHL/
t
PLH
PARAMETER
propagation delay
C
IN
to C
n+4
A
n
, B
n
to C
n+4
C
I
C
PD
Notes
1. C
PD
is used to determine the dynamic power dissipation (P
D
in
µW):
P
D
= C
PD
×
V
CC2
×
f
i
+
∑
(C
L
×
V
CC2
×
f
o
) where:
f
i
= input frequency in MHz
f
o
= output frequency in MHz
∑
(C
L
×
V
CC2
×
f
o
) = sum of outputs
C
L
= output load capacitance in pF
V
CC
= supply voltage in V
2. For HC the condition is V
I
= GND to V
CC
For HCT the condition is V
I
= GND to V
CC
−
1.5 V
input capacitance
power dissipation capacitance per package
notes 1 and 2
CONDITIONS
HC
C
L
= 15 pF; V
CC
= 5 V
20
23
3.5
116
23
27
3.5
120
ns
ns
pF
pF
HCT
UNIT
1998 Mar 31
2
PHILIPS [ NXP SEMICONDUCTORS ]
