7 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

7.1 Application Information

In this application, the CDx4AC(T)164 is used to control seven-segment displays. Unlike other I/O expanders,

the CDx4AC(T)164 does not need a communication interface for control. It can easily operate with simple GPIO

pins. Additional control is provided with two serial inputs that feed into an AND gate.

At power-up, the initial state of the shift registers is unknown. To give them a defined state, the shift register

needs to be cleared. An RC can be connected to the CLR pin as shown in Figure 7-1 to initialize the shift register

to all zeros.

7.2 Typical Application

Seven Segment

CLR

QA

QB

QC

QD

QE

QF

QG

QH

g

f

a

b

DP

c

d

e

a

b

c

d

e

f

g

DP

GND

VCC

A

B

CLK

MCU

R1

C1

VCC

Figure 7-1. Typical Application Block Diagram

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CD54AC164, CD74AC164, CD54ACT164, CD74ACT164

SCHS240D – NOVEMBER 1998 – REVISED OCTOBER 2024

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