PIN CONNECTIONS

4054B

4055B

4056B

as L, P, H, A,– , and a blank position. (see typical ap-

plication for other letters). The HCC/HCF4054B pro-

vides level shifting similar to the HCC/HCF4055B

and HCC/HCF4056B independently strobed latches,

and common DF control on 4 signal lines. The

HCC/HCF4054B is intended to provide drive-signal

compatibility

with

the

HCC/HCF4055B

and

HCC/HCF4056B 7-segment decoder types for the

decimal point, colon, polarity, and similar display lines.

A level-shifted high-amplitude DF output can be ob-

tained from any HCC/HCF4054B output line by con-

necting the corresponding input and strobe lines to

a

low

and

high

level,

respectively.

The

HCC/HCF4054B may also be utilized for logic-level

”up conversion” or ”down conversion”. Forexample,

+ 5 to – 5V. The level-shifted function on all three

types permits the use of different input-and output-

signal swings. The input swings from a low level of

Thus, the input and output swings can be selected

independently of each other over a 3-to-18V range.

function is required. For the HCC/HCF 4054B and

HCC/HCF 4056B, data are transferred from input to

output by placing a high voltage level at the strobe

input. A low voltage level at the strobe input latches

the data input and the corresponding output seg-

ments remain selected (or non-selected) while the

strobe is low. Whenever the level-shifting function

is required, the HCC/HCF4055B can be used by it-

self to drive a liquid-crystal display (fig. 10 and fig.

12). The HCC/HCF4056B, however, must be used

together with a HCC/HCF4054B to provide the com-

mon DF output (fig. 14). The capability of extending

the voltage swing on the negative end (this voltage

cannot be extended on the positive end) can be

used to advantage in the set-up of fig. 11. Fig. 9 is

common to all three types.

HCC/HCF4054B/55B/56B

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