HCC4054B Datasheet, PDF (10/15 Pages) STMicroelectronics – LIQUID-CRYSTAL DISPLAY DRIVERS

HCC/HCF4054B/55B/56B
TYPICAL APLLICATIONS (continued)
Figure 14 : Typical 3 ¹/₂ – Digit–crystal Display : (V_DD = + 5V, V_SS = 0V, V_EE = – 10V, DF_N = 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.
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