HCC/HCF4054B/55B/56B
TYPICAL APLLICATIONS (continued)
1
Figure 14 : Typical 3 /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. Ina similar manner the letters C,
E, J,and Ucan be displayed. These circuitscan 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.
10/15
ETC [ ETC ]
