on November 22th 6,769

Comprehensive Guide to PCF8575 I/O Expander

The PCF8575, crafted with precision by Texas Instruments, serves as an adaptable 16-bit I2C I/O expander equipped with interrupt capabilities. This article provides a comprehensive examination of its features, pin configuration, and technical schematics, along with a diverse array of applications. When utilized to extend the input/output ports of microcontrollers, the PCF8575 effectively navigates the demands of complex systems. Its flexibility shines in settings requiring seamless integration and reduced circuit intricacy. Hands-on experiences reveal that employing the PCF8575 can greatly simplify system design, presenting a budget-friendly approach to boosting computing capabilities.

Catalog

Overview of PCF8575

The PCF8575 serves as a versatile remote I/O expander, enabling seamless communication between microcontrollers via the I2C protocol. Utilizing SCL (serial clock line) and SDA (serial data line) for data transmission, simplifies circuit design by allowing high-current drive outputs, such as LEDs, without requiring additional data-direction signals. Upon initialization, all I/O pins default to a high state, activating an internal current source linked to VCC. This feature not only streamlines operations but also minimizes the need for auxiliary components, making the PCF8575 a valuable asset for various electronic applications.

One of the standout features of the PCF8575 is its support for both 3.3V and 5V systems, achieved through an integrated level converter. This broadens its compatibility with diverse microcontroller architectures, offering you greater flexibility and freedom in system design. The ability to work across different voltage standards eliminates a common challenge in multi-component systems, allowing you to focus on creative implementations without concerns about voltage incompatibility.

A major aspect of the PCF8575 is its configurable I2C interface, which enhances connectivity and device addressability in complex setups. With solder jumpers, you can adjust the I2C address from a base of 0x20, enabling effective communication across multiple devices. This adaptability is useful for avoiding addressing conflicts in intricate systems, a detail often emphasized by you. In addition, the device can be powered through either VDD or VCC, catering to varying logic level requirements. This flexibility simplifies integration with systems operating at 3.3V or 5V, ensuring stability and reliability in diverse applications.

Pin Configuration

PIN			TYPE	DESCRIPTION
NAME	DB, DBQ, DGV, DW, AND PW	RGE
A0	21	18	I	Address input 0. Connect directly to Vcc or ground. Pull-up resistors are not needed.
A1	2	23	I	Address input 1. Connect directly to Vcc or ground. Pull-up resistors are not needed.
A2	3	24	I	Address input 2. Connect directly to Vcc or ground. Pull-up resistors are not needed.
INT	1	22	O	Interrupt output. Connect to Vcc through a pull-up resistor.
P00	4	1	I/O	P-port input/output. Push-pull design structure.
P01	5	2	I/O	P-port input/output. Push-pull design structure.
P02	6	3	I/O	P-port input/output. Push-pull design structure.
P03	7	4	I/O	P-port input/output. Push-pull design structure.
P04	8	5	I/O	P-port input/output. Push-pull design structure.
P05	9	6	I/O	P-port input/output. Push-pull design structure.
P06	10	7	I/O	P-port input/output. Push-pull design structure.
P07	11	8	I/O	P-port input/output. Push-pull design structure.
GND	12	9	—	Ground
P10	13	10	I/O	P-port input/output. Push-pull design structure.
P11	14	11	I/O	P-port input/output. Push-pull design structure.
P12	15	12	I/O	P-port input/output. Push-pull design structure.
P13	16	13	I/O	P-port input/output. Push-pull design structure.
P14	17	14	I/O	P-port input/output. Push-pull design structure.
P15	18	15	I/O	P-port input/output. Push-pull design structure.
P16	19	16	I/O	P-port input/output. Push-pull design structure.
P17	20	17	I/O	P-port input/output. Push-pull design structure.
SCL	22	19	I	Serial clock line. Connect to Vcc through a pull-up resistor.
SDA	23	20	I/O	Serial data line. Connect to Vcc through a pull-up resistor.
Vcc	24	21	—	Supply voltage

CAD Details

Footprint

3D Representation

Features

Feature	Description
Low Standby-Current Consumption	10 µA Max
I²C to Parallel-Port Expander	Allows for easy expansion of I/O pins via I²C interface.
Open-Drain Interrupt Output	Enables external interrupt generation for microcontrollers.
Microcontroller Compatibility	Compatible with most microcontrollers.
I²C Bus Speed	400-kHz Fast I²C Bus.
Addressing	Addressable by three hardware address pins, allowing up to eight devices.
Latched Outputs	High-current drive capability for directly driving LEDs.
Current Source	Provides current to VCC for actively driving a high at the output.
Latch-Up Performance	Exceeds 100 mA per JESD 78, Class II.
Working Voltage	2.5 - 5.5V DC.
Working Current	100 mA (Max).
I²C Address	Default address: 0x20, modifiable via soldering A1 and A2 selection pads.
Addressable Pins	16 individually addressable pins.
Pin Configuration	Each pin configurable as input or output; supports input change interrupt.
Arduino Library	Compatible with Arduino library: PCF8575.
Application	Suitable for Arduino UNO R3 and other MCUs for controlling relays, buzzers, buttons, and LEDs.
ESD Protection	Complies with JESD 22: 2000-V Human-Body Model (A114-A), 200-V Machine Model (A115-A), 1000-V Charged-Device Model (C101).

Technical Specification

This table provides a clear and concise representation of the technical specifications and attributes for the Texas Instruments PCF8575PW.

Type	Parameter
Lifecycle Status	ACTIVE (Last Updated: 5 days ago)
Factory Lead Time	6 Weeks
Mounting Type	Surface Mount
Package / Case	24-TSSOP (0.173, 4.40mm Width)
Surface Mount	YES
Number of Pins	24
Weight	89.499445mg
Number of I/Os	16
Operating Temperature	-40°C ~ 85°C
Packaging	Tube
JESD-609 Code	e4
Pbfree Code	Yes
Part Status	Active
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Number of Terminations	24
ECCN Code	EAR99
Terminal Finish	Nickel/Palladium/Gold (Ni/Pd/Au)
HTS Code	8542.39.00.01
Voltage - Supply	4.5V ~ 5.5V
Terminal Position	DUAL
Terminal Form	GULL WING
Peak Reflow Temperature (°C)	260
Supply Voltage	3.3V
Terminal Pitch	0.65mm
Base Part Number	PCF8575
Pin Count	24
Number of Outputs	16
Output Type	Push-Pull
Operating Supply Voltage	5.5V
Power Supplies	3/5V
Interface	I2C, SMBus
Number of Ports	2
Number of Bits	16
Clock Frequency	400kHz
Supply Current-Max	0.2mA
Interrupt Output	Yes
Current - Output Source/Sink	10mA / 25mA
Features	POR
Height	1.2mm
Length	7.8mm
Width	4.4mm
Thickness	1mm
Radiation Hardening	No
RoHS Status	ROHS3 Compliant
Lead Free	Lead Free

Schematic Representation

Application Circuit

Logic Diagram

Layout Illustration

Diverse Uses of PCF8575

The PCF8575, a versatile I/O expander, significantly influences various technological arenas. Its diverse applications span across telecommunications, personal computing, and beyond, demonstrating its competence in managing multiple peripheral connections effectively.

Telecommunications Equipment

In the telecommunications sector, the PCF8575 enhances equipment like filter units by extending GPIO capabilities, enabling more exact control and precision within intricate signal processing environments. Its adaptability serves as a reliable partner for you striving to refine systems, ensuring stable connectivity and precise signal management.

Server Infrastructure

This component facilitates streamlined operations within server infrastructures, offering adaptable connections that are active for high-demand settings. It grants you the latitude to optimize server designs with flexibility and scalability, accommodating evolving demands with minimal hardware modifications.

Networking Routers

The PCF8575 plays a supportive role in networking routers by expanding device programmability and connectivity. By aiding the development of routers focused on robustness and adaptability, it helps create sophisticated solutions that effectively manage increasing data traffic.

Personal Computing Devices

In the world of personal computing, this I/O expander offers you the flexibility to innovate peripherals and enhancements without being overly constrained by system architecture limits. It encourages creativity in hardware design, advancing accessible technologies to market with efficiency.

Consumer Electronics

In the fast-paced consumer electronics market, the PCF8575 extends device features without the burden of major redesigns. This capability enables companies to introduce state-of-the-art features in compact designs, helping sustain a competitive presence in a constantly evolving industry.

Industrial Automation Systems

The PCF8575 is instrumental in industrial automation, facilitating exceptional process control and monitoring. By offering dangerous connectivity, it supports sophisticated operations management, enhancing efficiency and reducing downtime in manufacturing settings.

Devices with Limited GPIO Options

For devices limited by scarce GPIO availability, the PCF8575 presents a revolutionary solution by expanding ports, allowing improved interfacing with peripheral devices. This flexibility grants your creative room to develop innovative solutions tailored to specific user needs.

Package

Manufacturer

Texas Instruments (TI), headquartered in Dallas, Texas, has made remarkable contributions as a trailblazer in the semiconductor industry, mainly in integrated circuits. Known globally for its innovative spirit, TI has profoundly influenced numerous technological advancements through its breakthroughs in analog and embedded processing. Over time, the company has expanded its extensive patent collection and secured a strong market presence, reflecting its constant drive for excellence and innovation. Events in education and technology have been shaped by TI's diverse product lineup, including devices such as calculators, microcontrollers, and multi-core processors.xd