PCF8574RGTR

Compact I2C-based remote I/O expanders for electronic interfaces

Manufacturer: ti

series introduction

# PCF8574RGTR Product Series Introduction

## 1. Overview
The PCF8574RGTR is a highly versatile and widely used integrated circuit (IC) belonging to the family of 8 - bit I/O expanders. Manufactured by well - known semiconductor companies, this product series is designed to address the need for additional input/output (I/O) ports in various electronic systems. It offers a simple and cost - effective solution for expanding the I/O capabilities of microcontrollers, microprocessors, and other digital devices.

## 2. Key Features

### 2.1 I2C Interface
- The PCF8574RGTR communicates with the host device using the Inter - Integrated Circuit (I2C) bus protocol. This is a widely adopted serial communication protocol that requires only two wires (SDA - Serial Data Line and SCL - Serial Clock Line) for data transfer. The I2C interface simplifies the hardware design, reduces the number of pins required for communication, and allows multiple devices to be connected on the same bus, enabling easy system expansion.
- It supports a wide range of I2C clock frequencies, typically up to 400 kHz, which provides flexibility in different application scenarios where different data transfer speeds are required.

### 2.2 8 - Bit Bidirectional I/O Ports
- Each PCF8574RGTR device provides 8 general - purpose bidirectional I/O pins. These pins can be configured as either inputs or outputs according to the specific requirements of the application.
- When configured as inputs, the pins can be used to read external signals such as sensor outputs, switch states, or other digital signals. When configured as outputs, they can be used to control external devices like LEDs, relays, or other actuators.

### 2.3 Open - Drain Outputs
- The output pins of the PCF8574RGTR are open - drain. This means that they can sink current but cannot source it directly. Open - drain outputs offer several advantages, such as the ability to interface with different voltage levels and the ability to perform wired - AND operations when multiple open - drain outputs are connected together. It also allows for easy connection to external pull - up resistors, which can be used to set the desired output voltage level.

### 2.4 Low Power Consumption
- The PCF8574RGTR is designed to operate with low power consumption, making it suitable for battery - powered applications. It has a low standby current, which helps to extend the battery life of portable devices. The low power operation also reduces heat generation, improving the overall reliability and stability of the system.

### 2.5 Wide Operating Voltage Range
- It can operate over a wide voltage range, typically from 2.5V to 6V. This wide voltage range provides flexibility in different power supply configurations and allows the device to be used in a variety of electronic systems with different power requirements.

## 3. Applications

### 3.1 Consumer Electronics
- In smart home devices, the PCF8574RGTR can be used to expand the I/O ports of a microcontroller. For example, it can be used to read the states of multiple sensors such as door sensors, window sensors, and motion sensors, and control various actuators like smart plugs, light switches, and motorized blinds.
- In portable media players, it can be used to interface with additional buttons, switches, or status indicators, providing a more user - friendly interface.

### 3.2 Industrial Automation
- In industrial control systems, the PCF8574RGTR can be used to expand the I/O capabilities of Programmable Logic Controllers (PLCs) or other control units. It can be used to read the states of industrial sensors such as

Images for reference

16-VFQFN

16-VFQFN

16-VQFN (exposed pad)

16-VQFN (exposed pad)

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Datasheets

Partlist

PCF8574RGTR
PCF8574RGTR/BKN
PCF8574RGTRG4