HCF4056B

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INPUT EQUIVALENT CIRCUIT

PIN DESCRIPTION

FUNCTIONAL DIAGRAM

PIN No

SYMBOL

NAME AND FUNCTION

5, 3, 2, 4

9, 10, 11, 12,

13, 15, 14

a to g

7 - Segments Outputs

6

DISPLAY

FREQ. IN

Display Frequency Input

1

STROBE

Strobe Input

7

Negative Supply Voltage

8

Negative Supply Voltage

16

Positive Supply Voltage

When the DF input is low, the output segments will

be high when selected by the BCD inputs. When

the DF input is high, the output segments will be

low when selected by the BCD inputs. When a

square wave is present at the DF input, the

selected segments will have a square wave output

that is 180

° out of phase with the DF input. Those

segments which are not selected will have a

square wave output that is in phase with the input.

DF square wave repetition rates for liquid crystal

displays usually range from 30Hz (well above

flicker rate) to 200Hz (well below the upper limit of

the liquid crystal frequency response). HCF4056B

provides a strobed-latch function at the BCD

inputs. The decoding of all input combinations in

this device provides displays of 0 to 9 as well as L,

P, H, A, -, and a blank position. The level shifted

function permits the use of different input and

output signal swings. The input swings from a low

swings can be selected independently of each

required. The HCF4056B, however must be used

together with HCF4054B to provide the common

DF output.