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

Applications of the TCAL9539-Q1 use this device connected as a target to an I2C controller (processor), and the

I2C bus may contain any number of other target devices. The TCAL9539-Q1 is in a remote location from the

controller, placed close to the GPIOs to which the controller needs to monitor or control.

9.2 Typical Application

Figure 9-1 shows an application in which the TCAL9539-Q1 can be used.

P00

P01

P02

P03

P04

P05

A1

A0

A

B

P06

P07

P10

P11

P12

P13

P14

P15

P16

P17

V CC

V

CC

V

CC

Controlled Switch

(CBT Device)

GND

INT

SDA

SCL

10 kΩ

10 kΩ

10 kΩ

10 kΩ

2 kΩ

INT

Subsystem 1

(Temperature

Sensor)

Subsystem 2

(Counter)

TCAL9539-Q1

SDA

SCL

INT

GND

Keypad

ALARM

RESET

ENABLE

Subsystem 3

(Alarm)

Controller

1

2

3

4

5

6

7

8

10

11

12

13

14

15

16

17

19

20

22

23

18

9

21

100

100

100

RESET

24

V CC

kΩ

kΩ

kΩ

0.1 uF

GND

GND

A.

Device address configured as 1110100 for this example.

B.

P00, P02, and P03 are configured as outputs.

C.

P01 and P04 to P017 are configured as inputs.

D.

Resistors are required for inputs (on P port) that may float. If a driver to an input will never let the input float, a resistor is not needed.

Outputs (in the P port) do not need pullup resistors.

Figure 9-1. Typical Application Schematic

TCAL9539-Q1

SCPS285A – NOVEMBER 2022 – REVISED AUGUST 2023

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Product Folder Links: TCAL9539-Q1