ST HCF4056B User Manual

HCF4056B

BCD TO 7 SEGMENT DECODER /DRIVER

WITH STROBED LATCH FUNCTION

■ QUIESCENT CURRENT SPECIF. UP TO 20V

■ OPERATION OF LIQUID CR YSTAL S WITH

CMOS CIRCUITS PROVIDES ULTRA LOW
POWER DISPLAY.

■ EQUIVALENT AC OUTPUT DRIVE FOR

LIQUID CRYSTAL DISPLAYS - NO
EXTERNAL CAPACITOR REQUIRED

■ VOLTAGE DOUBLING ACROSS DISPLAY

[(V

- VEE) = 18V] RESU LT S IN EFFECTIVE

DD

36V (p-p) DRIVE ACROSS SELECTED
DISPLAY SEGMENTS

■ LOW OR HIGH OUTPUT LEVEL DC DRIVE

FOR OTHER TYPES OF DISPLAYS

■ ONE CHIP LOGIC LEVEL CONVERSION

FOR DIFFERENT INPUT AND OUTPUT
LEVEL SWINGS

■ FULL DECODING OF ALL INPUT

COMBINATIONS : "0 - 9, L, H, P, A" AND
BLANK POSITIONS

■ INPUT LEAKAGE CURRENT

I

= 100nA (MAX) AT VDD = 18V TA = 25°C

I

■ 100% TESTED FOR QUIESCENT CURRENT

■ MEETS ALL REQUIREMENTS OF JEDEC

JESD13B "STANDARD SPECIFICATIONS
FOR DESCRIPTI ON OF B SERI ES CMOS
DEVICES"

DESCRIPTION

HCF4056B is a monolithic integrated circuit
fabricated in Metal Oxide Semiconductor
technology available in DIP and SOP packages.

DIP SOP

ORDER CODES

PACKAGE TUBE T & R

DIP HCF4056BEY

SOP HCF4056BM1 HCF4056M013TR

HCF4056B is a single digit BCD to 7 segment
decoder driver circuit that provides a leve l shifting
function on the chip. This feature permits the BCD
input-signal swings (V

to VSS) to be th e same

DD

as or different from the 7-s egment output signal
swings (V
input-signal swings (V

to VEE). For example, the BCD

DD

to VSS) may be as low as

DD

0 to -3V, whereas the output-display drive signa l
swing (V
V

exceeds 15V, VDD to VSS should be at least

EE

to VEE) may be from 0 to -5V . If VDD to

DD

4V. The 7-segment outputs are controlled by the
DISPLAY-FREQUENCY (DF) input, which causes
the selected segment outputs to be low, high, or a
square wave output (for liquid crystal displays).

PIN CONNECTION

1/10September 2002

HCF4056B

When the DF input is low, the output segments will
be high when select ed by the BCD inp uts. 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 crys tal
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 dec oding of all input combinat ions 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
level of V

to a high level of V

SS

outputs swing from a low level of V
high level of V

. Thus, the input and output

DD

swings can be selected independently of each
other over a 3 to 18V range. V
con nected to V

when no level-shift function is

EE

required. The HCF4056B, however m ust be used
together with HCF4054B to provide the common
DF output.

INPUT EQUIVALENT CIRCUIT PIN DESCRIPTION

PIN No SYMBOL NAME AND FUNCTION

5, 3, 2, 4

9, 10, 11, 12,

13, 15, 14

6
1 STROBE Strobe Input

7
8

16

0

2

, 21, 22, 2

a to g 7 - Segments Outputs

DISPLAY

FREQ. IN

V

EE

V

SS

V

DD

while the

DD,

to the same

EE

may be

SS

3

BCD Inputs

Display Frequency Input

Negative Supply Voltage
Negative Supply Voltage
Positive Supply Voltage

FUNCTIONAL DIAGRAM

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TRUTH TABLE

HCF4056B

INPUT CODE OUTPUT STATE

3

2

2

2

1

2

0

2

abcdefg

DISPLAY

CHARACTER

LL LLHHHHHHL 0
LLLHLHHLLLL 1
LLHLHHLHHLH 2
LLHHHHHHLLH 3
LHLLLHHLLHH 4
LHLHHLHHLHH 5
LHHLHLHHHHH 6

LHHHHHHLLLL 7
HL LLHHHHHHH 8
HL LHHHHHLHH 9
HLHLLLLHHHL L
HLHHLHHLHHH H
HHL LHHLLHHH P
HHLHHHHLHHH A
HHHLLLLLLLH ­H H H H L L L L L L L BLANK

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

V

P

T

T

Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied.
All voltage value s are referred to V

Supply Voltage

DD

DC Input Voltage -0.5 to VDD + 0.5

I

I

DC Input Current

I

Power Dissipation per Package 200 mW

D

-0.5 to +22 V

10 mA

±

Power Dissipation per Output Transistor 100 mW
Operating Temperature

op

Storage Temperature

stg

pin voltage.

SS

-55 to +125 °C

-65 to +150 °C

V

RECOMMENDED OPERATING CONDITIONS

Symbol Parameter Value Unit

V

V

T

Supply Voltage

DD

Input Voltage 0 to V

I

Operating Temperature

op

3 to 20 V

DD

-55 to 125 °C

V

3/10