HCC/HCF4026B
HCC/HCF4033B
DECADE COUNTERS/DIVIDERS WITH DECODED
7-SEGMENT DISPLAY OUTPUTS
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WITH; DISPLAY ENABLE 4026B
RIPPLE BLANKING 4033B
COUNTER AND 7-SEGMENT DECODING IN
ONE PACKAGE
EASILY INTERFACED WITH 7-SEGMENT DIS-
PLAY TYPES
FULLY STATIC COUNTER OPERATION : DC
TO 6MHz (typ.) AT V
DD
= 10V
IDEAL FOR LOW-POWER DISPLAYS
DISPLAY ENABLE OUTPUT - 4026B
”RIPPLE BLANKING” AND LAMP TEST - 4033B
QUIESCENT CURRENT SPECIFIED TO 20V
FOR HCC DEVICE
STANDARDIZED SYMMETRICAL OUTPUT
CHARACTERISTICS
5V, 10V, AND 15V PARAMETRIC RATING
INPUT CURRENT OF 100nA AT 18V AND 25°C
FOR HCC DEVICE
100% TESTED FOR QUIESCENT CURRENT
MEETS ALL REQUIREMENTS OF JEDEC TEN-
TATIVE STANDARD N° 13A, ”STANDARD SPE-
CIFICATIONS FOR DESCRIPTION OF ”B”
SERIES CMOS DEVICES”
EY
(Plastic Package)
F
(Ceramic Frit Seal Package)
M1
(Micro Package)
C1
(Plastic Chip Carrier)
ORDER CODES :
HCC40XXBF
HCF40XXBM1
HCF40XXBEY
HCF40XXBC1
PIN CONNECTIONS
DESCRIPTION
The
HCC4026B/4033B
(extended temperature
range) and
HCF4026B/4033B
(intermediate tem-
perature range) are monolithic integrated circuits,
available in 16-lead dual in-line plastic or ceramic
package and plastic micro package. The
HCC/HCF4026B
and
HCC/HCF4033B
each con-
sist of a 5-stage Johnson decade counter and an
output decoder which converts the Johnson code to
a 7-segment decoded output for driving one stage
in a numerical display. These devices are particu-
larly advantageous in display applications where
low power dissipation and/or low package count are
important. Inputs common to both types are
CLOCK, RESET, & CLOCK INHIBIT ; common out-
puts are CARRY OUT and the seven decoded out-
puts (a, b, c, d, e, f, g). Additional inputs and outputs
for the
HCC/HCF4026B
include DISPLAY ENABLE
input and DISPLAY ENABLE and UNGATED ”C-
SEGMENT” outputs. Signals peculiar to the
HCC/HCF4033B
are RIPPLE-BLANKING INPUT
AND LAMP TEST INPUT and a RIPPLE-BLANK-
ING OUTPUT. A high RESET signal clears the de-
June 1989
4026B
4033B
1/15
HCC/HCF4026B/4033B
cade counter to its zero count. The counter is ad-
vanced one count at the positive clock signal tran-
sition if the CLOCK INHIBIT signal is low. Counter
advancement via the clock line is inhibited when the
CLOCK INHIBIT signal is high. Antilock gating is
provided on the JOHNSON counter, thus assuring
proper counting sequence. The CARRY-OUT (C
out
)
signal completes one cycle every ten CLOCK
INPUT cycles and is used to clock the succeeding
decade directly in a multi-decade counting chain.
The seven decoded outputs (a, b, c, d, e, f, g) illumi-
nate the proper segments in a seven segment dis-
play device used for representing the decimal
numbers 0 to 9. The 7-segment outputs go high on
selection in the
HCC/HCF4033B
; in the
HCC/-
HCF4026B
these outputs go high only when the
DISPLAY ENABLE IN is high.
HCC/HCF4026B
- When the DISPLAY ENABLE IN
is low the seven decoded outputs are forced low re-
gardless of the state of the counter. Activation of the
display only when required results in significant
power savings. This system also facilitates im-
plementation of display-character multiplexing. The
CARRY OUT and UNGATED ”C-SEGMENT” sig-
nals are not gated by the DISPLAY ENABLE and
therefore are available continuously. This feature is
a requirement in implementation of certain divider
functions such as divide-by-60 and divide-by-12.
HCC/HCF4033B
- The
HCC/HCF4033B
has provi-
sions for automatic blanking of the non-significant
zeros in a multi-digit decimal number which results
in an easily readable display consistent with
normal writing practice. For example, the number
0050.07000 in an eight digit display would be dis-
played as 50.07. Zero suppression on the integer
side is obtained by connecting the RBI terminal of
the
HCC/HCF4033B
associated with the most sig-
nificant digit in the display to a low-level voltage and
connecting the RBO terminal of that stage to the RBI
terminal of the
HCC/HCF4033B
in the next-lower
significant position in the display. This procedure is
continued for each succeeding
HCC/HCF4033B
on
the integer side of the display. On the fraction side
of the display the RBI of the
HCC/HCF4033B
asso-
ciated with the least significant bit is connected to a
low-level voltage and the RBO of that
HCC/-
HCF4033B
is connected to the RBI terminal of the
HCC/HCF4033B
in the next more-significant-bit po-
sition. Again, this procedure is continued for all
HCC/HCF4033B’s
on the fraction side of the dis-
play. In a purely fractional number the zero immedi-
ately preceding the decimal point can be displayed
by connecting the RBI of that stage to a high level
voltage (instead of to the RBO of the next more-sig-
nificant-stage). For example : optional zero
→
0.7346. Likewise, the zero in a number such as
763.0 can be displayed by connecting the RBI of the
HCC/HCF4033B
associated with it to a high-level
voltage. Ripple blanking of non-significant zeros
provides an appreciable savings in display power.
The
HCC/HCF4033B
has a LAMP TEST input
which, when connected to a high-level voltage,
overrides normal decoder operation and enables a
check to be made on possible display malfunctions
by putting the seven outputs in the high state.
2/15
Electronics Design Contest
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