74HC283 Philips, 74HC283 Datasheet - Page 8

• Manufacturer Part Number: 74HC283
• Description: 4-bit binary full adder with fast carry
• Manufacturer: Philips

Philips Semiconductors
AC WAVEFORMS
Notes to Figs 7 to 10
Figure 7 shows a 3-bit adder using the “283”. Tying the
operand inputs of the fourth adder (A
dependent on, and equal to, the carry from the third adder.
Based on the same principle, Figure 8 shows a method of
dividing the “283” into a 2-bit and 1-bit adder. The third
stage adder (A
transferring the carry into the fourth stage (via A
and transferring the carry from the second stage on
Note that as long as long as A
or LOW, they do not influence
B
influence the carry out of the third stage. Figure 9 shows a
method of implementing a 5-input encoder, where the
December 1990
2
4-bit binary full adder with fast carry
are the same, the carry into the third stage does not
(1) HC : V
Fig.6
HCT: V
Waveforms showing the inputs (C
to the outputs (
and the output transition times.
M
M
= 50%; V
= 1.3 V; V
2
, B
Fig.9 5-input encoder.
2
,
I
I
= GND to V
= GND to 3 V.
2
) is used simply as means of
n
, C
2
CC
and B
OUT
.
2
. Similarly, when A
) propagation delays
3
2
, B
are the same, HIGH
3
) LOW makes
IN
, A
2
n
and B
, B
2
n
and
)
2
.
2
3
)
8
APPLICATION INFORMATION
inputs are equally weighted. The outputs
produce a binary number equal to the number inputs (I
I
implementing a 5-input majority gate. When three or more
inputs (I
PACKAGE OUTLINES
See
5
) that are HIGH. Figure 10 shows a method of
“74HC/HCT/HCU/HCMOS Logic Package Outlines”
1
to I
5
) are HIGH, the output M
Fig.10 5-input majority gate.
Fig.8 2-bit and 1-bit adder.
Fig.7 3-bit adder.
74HC/HCT283
Product specification
5
is HIGH.
0
,
1
and
1
to
2
.