MOTOROLA CMOS LOGIC DATA

1

MC14534B

5 Cascaded BCD Counters

The MC14534B is composed of five BCD ripple counters that have their

respective outputs multiplexed using an internal scanner. Outputs of each

counter are selected by the scanner and appear on four (BCD) pins.

Selection is indicated by a logic high on the appropriate digit select pin. Both

BCD and digit select outputs have three–state controls providing an

“open–circuit” when these controls are high and allowing multiplexing.

Cascading may be accomplished by using the carry–out pin. The counters

and scanner can be independently reset by applying a high to the counter

master reset (MR) and the scanner reset (SR). The MC14534B was

specifically designed for application in real time or event counters where

continual updating and multiplexed displays are used.

• Four Operating Modes (See truth table)

• Input Error Detection Circuit

• Clock Conditioning Circuits for Slow Transition Inputs

• Counter Sequences on Positive Transition of Clock A

• Supply Voltage Range = 3.0 Vdc to 18 Vdc

• Capable of Driving Two Low–power TTL Loads or One Low–power

Schottky TTL Load Over the Rated Temperature Range

BLOCK DIAGRAM

PULSE ERROR

DETECTOR

PULSE

SHAPER

TEST

CONTROL

OUTPUT

CONTROL

MUX

MUX

MUX

MUX

MUX

UNITS

CARRY

CONTROL

TENS

HUNDREDS

THOUSANDS

TEN

THOUSANDS

C

÷ 10

C

÷ 10

C

÷ 10

C

÷ 10

C

÷ 10

Q0

Q3

Q0

Q3

Q0

Q3

Q0

Q3

Q0

Q3

Cn+4

Cn+4

Cn+4

Cn+4

Cn+4

22

7

8

14

16

11

1

23

4

2

5

6

9

10

CLOCK B

CLOCK A

MASTER

RESET

MODE A

MODE B

SCANNER

RESET

SCANNER

CLOCK

ERROR OUT

3

R

SCANNER

13

17

18

19

20

Q3

Q2

Q1

Q0

21

3–STATE BCD

CONTROL

CARRY OUT

3–STATE DIGIT

CONTROL

15

DS1

DS2

DS3

DS4

DS5

DIGIT SELECT

3–STATE

OUTPUT BUFFER

NOTE:

BCD

OUT

VDD = PIN 24

VSS = PIN 12

TO CAPACITORS

3–State Control

Out

Q or DS

High Impedance

0

1

=

MOTOROLA

SEMICONDUCTOR TECHNICAL DATA

REV 3

1/94

MC14534B

L SUFFIX

CERAMIC

CASE 623

ORDERING INFORMATION

MC14XXXBCP

Plastic

MC14XXXBCL

Ceramic

MC14XXXBDW

SOIC

TA = – 55° to 125°C for all packages.

P SUFFIX

PLASTIC

CASE 709

DW SUFFIX

SOIC

CASE 751E