HCC4054B datasheet(10/15 Pages) STMICROELECTRONICS

10 / 15 page

TYPICAL APLLICATIONS (continued)

Figure 14 : Typical 3 1/2 – Digit–crystal Display : (VDD =+5V, VSS = 0V, VEE = – 10V, DFN = 30 Hz square).

In addition to the letters L, H, P, and A, five other let-

ters can be displayed through the use of simple

logic

circuits

preceding

and

following

the

HCC/HCF4055B or

HCC/HCF4056B

devices.

Fig. 13 is an example of a circuit that converts an ”H”

display, (code 1011) to an ”F” display. One condition

that must be met is that VEE =VSS.If VEE

≠ VSS,the

HCC/HCF4054B must be used to level shift in the

appropriate places. In a similar manner the letters C,

E, J,and U can be displayed. These circuits can also

be used to drive LED displays provided the exclu-

sive-OR gates have sufficient output-current drive.

The letters B, D, G, I, O, and S may be represented

by the codes for numbers 8, 0, 6, 1, 0, and 5, respec-

tively, when there is preknowledge that only letters

are to be displayed.

HCC/HCF4054B/55B/56B

10/15

HCC4054B Datasheet(PDF) 10 Page - STMicroelectronics