9 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. Customers should validate and test their design

implementation to confirm system functionality.

9.1 Application Information

The SN74HCS259-Q1 has four modes of operation. In this application, the 8-line demultiplexer mode is used to

send data to one of eight possilbe desinations.

At system power-on, latched outputs are in an unknown state. The CLR input is held low while the G input is

held high to clear the latches for operation. At this time, all outputs are in the low state.

An output is selected by setting S2, S1, and S0 as per the Latch Selection Table. After selection, the channel is

activated by switching G to low. The logic value at the D input will appear at the selected output, allowing data

transmission only to the selected device.

When the channel communication is complete, the G input is set to high to prevent erronous outputs while the

address inputs are changed, then switched back to low again to send data to the newly selected device.

9.2 Typical Application

System Controller

Q0

Q1

Q2

Q3

Q4

Q5

Q6

Q7

D

G

CLR

0.1µF

5V

Device 1

Device 2

Device 3

Device 4

Device 5

Device 6

Device 7

Device 8

S0

S1

S2

GND

Figure 9-1. Typical application block diagram

9.2.1 Design Requirements

9.2.1.1 Power Considerations

Ensure the desired supply voltage is within the range specified in the Recommended Operating Conditions. The

supply voltage sets the device's electrical characteristics as described in the Electrical Characteristics.

The positive voltage supply must be capable of sourcing current equal to the total current to be sourced by all

and any transient current required for switching. The logic device can only source as much current as is provided

Absolute Maximum Ratings.

SN74HCS259-Q1

SCLS815A – JULY 2020 – REVISED DECEMBER 2021

www.ti.com

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