HCC/HCF4054B/55B/56B
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, andsimilar display lines.
A level-shifted high-amplitude DF output can be ob-
tainedfrom any HCC/HCF4054B output line bycon-
necting the corresponding input and strobe lines to
from a low level ofVEE tothe same highlevel of VDD.
Thus, the input and output swings can be selected
independently of each other over a 3-to-18V range.
VSS may be connected to VEE when no level-shift
function is required. For the HCC/HCF 4054B and
HCC/HCF4056B, 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 witha HCC/HCF4054Btoprovide 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.
a
low and high level, respectively. The
HCC/HCF4054B may also be utilized for logic-level
”upconversion” or ”down conversion”. Forexample,
input-signal swings (VDD to VSS) from + 5 to 0V can
be converted to output-signal swings (VDD to VEE) of
+ 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
VSS to a high level of VDD while the output swings
PIN CONNECTIONS
4054B
4055B
4056B
2/15
ETC [ ETC ]
