December 1990

8

Philips Semiconductors

Product specification

4-bit binary full adder with fast carry

74HC/HCT283

AC WAVEFORMS

Fig.6

to the outputs (

and the output transition times.

APPLICATION INFORMATION

Fig.7 3-bit adder.

Fig.8 2-bit and 1-bit adder.

Fig.9 5-input encoder.

Fig.10 5-input majority gate.

Notes to Figs 7 to 10

Figure 7 shows a 3-bit adder using the “283”. Tying the

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

and transferring the carry from the second stage on

or LOW, they do not influence

influence the carry out of the third stage. Figure 9 shows a

method of implementing a 5-input encoder, where the

inputs are equally weighted. The outputs

∑

implementing a 5-input majority gate. When three or more

PACKAGE OUTLINES

See