We are Apogeeweb Semiconductor Electronic

WELCOME TO OUR BLOG

Home  Product Technical Articles   PCF8574T I/O Expander: Arduino, datasheet, PDF and Pinout [Video&FAQ]

PCF8574T I/O Expander: Arduino, datasheet, PDF and Pinout [Video&FAQ]

Author: Irene
Date: 17 Nov 2021
 950
Arduino

The PCF8574T IO Expansion Board is used as remote 8-bit I/O expander for I2C-bus.

 

Catalog

Product Overview

CAD Model

Product Pinout

PCF8574T Attributes

Family Overview

Applications

PCF8574T-Datasheet

PCF8574T Circuit

PCF8574T Raspberry Pi

Reference

PCF8574T FAQ

Product Overview

The PCF8574T IO Expansion Board is used as remote 8-bit I/O expander for I2C-bus.Up to 8 PCF8574T IO Expansion Board can be connected to the I2C-bus, providing up to 64 I/O ports.

 

The PCF8574T IO Expansion Board features allowing the use of multi module connected to the I2C bus at the same time by connecting the pinheader and connector.

There is a small potentiometer onboard, which can adjust the backlight of LCD1602 or LCD2004, and a jumper cap to control the switch of the LED light.

 

CAD Model

PCF8574T-Part-Symbol

 

PCF8574T-Part Symbol

 

PCF8574T-Footprint

 

PCF8574T-Footprint

 

PCF8574T-3D-Model

 

PCF8574T-3D-Model

 

Product Pinout

PCF8574T-Pinout

 

PCF8574T-Pinout

 

PCF8574T Attributes

Source Content uid: PCF8574T
Manufacturer Part Number: PCF8574T
Part Life Cycle Code: Active
Ihs Manufacturer: NXP SEMICONDUCTORS
Part Package Code: SOIC
Package Description: SOP, SOP16,.4
Pin Count: 16
Reach Compliance Code: compliant
ECCN Code: EAR99
HTS Code: 8542.39.00.01
Manufacturer: NXP Semiconductors
Risk Rank: 1.53
Samacsys Description: NXP - PCF8574T. - IC, SM I/O EXPANDER 8-BIT
Samacsys Manufacturer: NXP
Clock Frequency-Max: 0.1 MHz
External Data Bus Width: 1
JESD-30 Code: R-PDSO-G16
Length: 10.3 mm
Moisture Sensitivity Level: 2
Number of Bits: 8
Number of I/O Lines: 8
Number of Ports: 1
Number of Terminals: 16
Operating Temperature-Max: 85 °C
Operating Temperature-Min: -40 °C
Package Body Material: PLASTIC/EPOXY
Package Code: SOP
Package Equivalence Code: SOP16,.4
Package Shape: RECTANGULAR
Package Style: SMALL OUTLINE
Peak Reflow Temperature (Cel): 260
Power Supplies: 3/5 V

 

Family Overview

Family overview The Philips family of I2C/SMBus General Purpose parallel Input/Output (GPIO) devices provides a simple solution for application requiring more I/Os. About 20 different devices can be chosen from two sub-families, commonly called ‘quasi bi-directional General Purpose I/Os’ and ‘totem-pole General Purpose I/Os’. Devices can be chosen with 4-bit, 8-bit or 16-bit width. Additional features (not available on all the devices) are active-LOW Interrupt output, active-LOW Reset input, programmable I2C address pins and low power consumption.

 

Finally, some devices come with additional functions (EEPROM, DIP switch) providing integrated and price attractive combination solutions. Quasi bi-directional GPIOs use a push-pull I/O port with an internal weak current-source pull-up to keep the port HIGH since the upper transistor is on for only 1⁄ 2 clock cycle. Totem-pole GPIOs use a configuration register that programs an I/O port as either an input or output.

 

Devices with a Reset input pin (RESET) can be set to a known default state by a master device when, for instance, an ‘I2C-bus hung’ situation occurs, thus allowing the master to take control of the bus without having to cycle power to the device. Devices with an Interrupt output pin (INT) are able to provide an ‘input change’ status to a master device anytime an I/O used as an input changes its logic state. Programmable I2C address pins allow more than one device in the same I2C-bus without any address conflicts.

 

Low power consumption GPIOs are attractive for portable applications or in general any application where current consumption is a key parameter. The following is a selection guide that provides the designers and engineers with an overview of the similarities and important differences, allowing them to select the best port expander for the job. Even though important technical details are explained in this application note, the reader is encouraged to thoroughly review the data sheets for specific information on the device.

 

Applications

  • Keypad and switch control
  • ACPI power switch, relays, timer
  • LED control
  • Signal monitoring
  • Sensors, fan control

 

PCF8574T-Datasheet

You can download the datasheet from the link given below:

PCF8574T-Datasheet

 

PCF8574T Circuit

Interfacing Arduino with I2C LCD circuit:

Example circuit diagram is shown in the image below.

  • The main component of the I2C LCD display is the PCF8574 I/O expander, with only two pins SDA and SCL we get a maximum of 8 pins from P0 to P7. PCF8574A also can be used but it has a different address.
  • All LCD data pins are connected to the PCF8574 where: RS, RW, E, D4, D5, D6 and D7 are connected to P0, P1, P2, P4, P5, P6 and P7 respectively.
  • PCF8574 I/O expander SDA and SCL pins are connected to Arduino pin A4 and A5 respectively (Arduino SDA and SCL pins).
  • PCF8574 I/O expander A0, A1 and A2 pins are the address pins which decide the I2C address of the chip. In this example each pin is connected to +5V through a 10k ohm resistor (the 10k resistor is optional, each pin can be connected directly to +5V).
  • The I2C address of the PCF8574 is: 0x20 | A2 A1 A0 ( | means OR)
    In our circuit A2, A1 and A0 are connected to +5V (through 10k resistors) which means the I2C address is equal to 0x20 | 7 = 0x27
  • If the PCF8574A is used instead of the PCF8574 the I2C address is: 0x38 | 7 = 0x3F.

 

PCF8574T Raspberry Pi

Comimark 3Pcs PCF8574 PCF8574T I2C 8 Bit IO GPIO Expander Module for Arduino & Raspberry Pi

  • I2C interface, I / O expansion module, two I / O scalability 8 I / O (up to 8 simultaneous use the PCF8574 expanded to 64 I / O)
  • Typical application: I / O resource shortage MCU I / O expansion
  • Main resources: the PCF8574 I2C interface, 8-bit parallel
  • Package Included: 3 x PCF8574 IO Expansion Board I/O Expander I2C-Bus Evaluation Development Module

 

Reference

PCF8574T Chip Datasheet: File:PCF8574T Datasheet.pdf

WiringPi: [ http://wiringpi.com/extensions/i2c-pcf8574/ ]

telecnatron:[ https://telecnatron.com/articles/Utility-To-Control-1602-LCD-On-Raspberry-Pi-Via-A-PCF8574-I2C-Backpack-Module/index.html]

Circuitbasics:[ https://www.circuitbasics.com/raspberry-pi-i2c-lcd-set-up-and-programming/ ]

 

PCF8574T FAQ

What is pcf8574t?

The PCF8574/74A provides general-purpose remote I/O expansion via the two-wire bidirectional I2C-bus (serial clock (SCL), serial data (SDA)). The devices consist of eight quasi-bidirectional ports, 100 kHz I2C-bus interface, three hardware address inputs and interrupt output operating between 2.5 V and 6 V.

 

How connect PCF8574 to Arduino?

1.Use PCF8574(A) I2C GPIO to add more digital pins to Arduino.

2.Components.

3.Set the PCF8574/PCF8574A I2C Address.

4.Connect the PCF8574/PCF8574A GPIO Module to the Arduino.

5.Connect the Button and the LED Modules.

6.Connect the Power Wires together.

7.Step 6: Connect the Ground Wires together.

 

How do I program PCF8574?

After connecting the I2C Module to LCD, connect the GND and VCC pins of the PCF8574 Module to GND and 5V pins of Arduino. Finally, the SDA and SCL Pins. Connect them to pins A4 and A5 pins of Arduino UNO respectively.

 

What is I2C IO Expander?

The I2C-bus allows easy two-line communication between two devices using a serial data line (SDA) and a serial clock line (SCL) and, as a result, is a popular choice for computing, consumer electronics, communication, and industrial systems.

 

What is the function of an IO Expander?

NXP's general-purpose input/output (GPIO) expanders are a simple, cost-effective way to monitor and control several peripheral signals. They make it easy for designers to add extra I/O to their design and thereby free up the microprocessor's GPIO for other, more important functions.

 

Ordering & Quality

Photo Mfr. Part # Company Description Package PDF Qty Pricing
(USD)
PCF8574T-3-512 PCF8574T-3-512 Company:NXP USA Inc. Remark:IC I/O EXPANDER I2C 8B 16SOIC Package:16-SOIC (0.295", 7.50mm Width)
DataSheet
In Stock:607
Inquiry
Price:
1+: $1.44000
10+: $1.28700
25+: $1.22160
100+: $0.93800
250+: $0.82896
500+: $0.78534
1000+: $0.61082
2500+: $0.58028
5000+: $0.55846
Inquiry
PCF8574T-3-518 PCF8574T-3-518 Company:NXP USA Inc. Remark:IC I/O EXPANDER I2C 8B 16SOIC Package:16-SOIC (0.295", 7.50mm Width)
DataSheet
In Stock:11000
Inquiry
Price:
1000+: $0.61082
2000+: $0.58028
5000+: $0.55846
10000+: $0.54101
25000+: $0.52356
1+: $1.44000
10+: $1.28700
25+: $1.22160
100+: $0.93800
250+: $0.82896
500+: $0.78534
Inquiry
PCF8574TS-3-112 PCF8574TS-3-112 Company:NXP USA Inc. Remark:IC I/O EXPANDER I2C 8B 20SSOP Package:20-LSSOP (0.173", 4.40mm Width)
DataSheet
In Stock:4
Inquiry
Price:
1+: $1.44000
Inquiry
PCF8574TS-3-118 PCF8574TS-3-118 Company:NXP USA Inc. Remark:IC I/O EXPANDER I2C 8B 20SSOP Package:20-LSSOP (0.173", 4.40mm Width)
DataSheet
In Stock:17500
Inquiry
Price:
2500+: $0.58028
5000+: $0.55846
12500+: $0.54101
25000+: $0.52356
1+: $1.44000
10+: $1.28700
25+: $1.22160
100+: $0.93800
250+: $0.82896
500+: $0.78534
1000+: $0.61082
Inquiry

Related Articles

Difference Between lR44 Battery vs 357 Battery [FAQ]

Irene 25 Sep 2021  3866

lR44 batteries and 357 batteries that are round, flat, and look like small silver buttons seem to look the same. Since they all look the same, can they be used universally?    This article...

Continue reading »

MCP3008 A/D Converter: Pinout, Datasheet, Raspberry Pi Setup [Video]

Mia 29 Mar 2021  1190

MCP3008 is a low cost 8-channel 10-bit analog to digital converter.   This blog covers the detailed information of MCP3008 A/D converter, including its pinout, parameter, features, where and ho...

Continue reading »

LM324N Quad Op Amp: Pinout, Datasheet,Circuit [Video]

Mia 7 Jan 2021  1012

LM324N is a quad-operational amplifier, it consists of four independent op-amp that are incorporated in a single 14 pin DIP package. Operational amplifiers are the initial devices that were used in an...

Continue reading »

MCP602 Linear IC Op Amp Datasheets and Basic Overview

Irene 1 Sep 2021  236

Product OverviewMCP602 family of low-power operational amplifiers (op amps) are offered in single (MCP601), single with Chip Select (CS) (MCP603), dual (MCP602), and quad (MCP604) configurations. Here...

Continue reading »

LM1875 Circuit: 22W Audio Amplifier

Mia 31 Jul 2020  940

I Description LM1875 is a power amplifier integrated block chip. Its superior performance and attractive tone have been accepted by many enthusiasts, and it was all the rage in the 1990s. LM1875 ado...

Continue reading »

0 comment

Leave a Reply

Your email address will not be published.

 
 
   
 
Rating:

# 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z