Interface - I/O Expanders

Category Introduction

Devices in this family are used in conjunction with microcontrollers, microprocessors, or similar devices for the purpose of increasing the number of signal connections available for connecting peripheral devices. The typical concept of operation involves the use of serial communications requiring only a few I/O lines on the host device to read/write the status of many input/output pins on the expander device. The technique exchanges speed of communication for increased connectivity, and is best suited for applications where fast response is not critical, such as in many human interface applications.

Product List

381 Items

Mfr Part #	Quantity Available	UnitPrice	Series	Packaging	Product Status	Number of I/O	Interface	Interrupt Output	Features	Output Type	Current - Output Source/Sink	Clock Frequency	Voltage - Supply	Operating Temperature	Mounting Type	Package / Case	Supplier Device Package
FXL6408UMX IC GPIO EXPANDER I2C 8B 16-UMLP onsemi	310	$1.68		Tape & Reel (TR)	Active	8	I²C	Yes	POR	Open Drain	6mA	400 kHz	1.65V ~ 4V	-40°C ~ 85°C	Surface Mount	16-UFQFN	16-UMLP (1.8x2.6)
PCA9534RGVR IC I/O EXPANDER I2C 8B 16QFN Texas Instruments	372	$2.03		Tape & Reel (TR)	Active	8	I²C, SMBus	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	2.3V ~ 5.5V	-40°C ~ 85°C	Surface Mount	16-VQFN Exposed Pad	16-VQFN (4x4)
PCA9570GMH IC GPIO EXPANDER 8XQFN NXP USA Inc.	403	$0.83		Tape & Reel (TR)	Active	4	I²C, SMBus	No	POR	Push-Pull	4mA	100 kHz	1.1V ~ 3.6V	-40°C ~ 85°C	Surface Mount	8-XFQFN Exposed Pad	8-XQFN (1.6x1.6)
PCA9554ADWR IC I/O EXPANDER I2C 8B 16SOIC Texas Instruments	113	$1.58		Tape & Reel (TR)	Active	8	I²C, SMBus	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	2.3V ~ 5.5V	-40°C ~ 85°C	Surface Mount	16-SOIC (0.295", 7.50mm Width)	16-SOIC
PCAL6416AHF,128 IC I/O EXPANDER 16BIT 24HWQFN NXP USA Inc.	183	$1.64	Agile	Tape & Reel (TR)	Active	16	I²C, SMBus	Yes	POR	Open Drain, Push-Pull	10mA, 25mA	400 kHz	1.65V ~ 5.5V	-40°C ~ 85°C	Surface Mount	24-WFQFN Exposed Pad	24-HWQFN (4x4)
PCA9557PW,118 IC I/O EXPANDER I2C 8B 16TSSOP NXP USA Inc.	120	$1.69		Tape & Reel (TR)	Active	8	I²C, SMBus	No	POR	Open Drain, Push-Pull	10mA, 20mA	400 kHz	2.3V ~ 5.5V	-40°C ~ 85°C	Surface Mount	16-TSSOP (0.173", 4.40mm Width)	16-TSSOP
PCA9554BPWJ IC GPIO EXPANDER 16TSSOP NXP USA Inc.	48	$1.80		Tape & Reel (TR)	Active	8	I²C, SMBus	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	1.65V ~ 5.5V	-40°C ~ 85°C	Surface Mount	16-TSSOP (0.173", 4.40mm Width)	16-TSSOP
PCF8574T/3,518 IC I/O EXPANDER I2C 8B 16SOIC NXP USA Inc.	433	$1.86		Tape & Reel (TR)	Active	8	I²C	Yes	POR	Push-Pull	300µA, 25mA	100 kHz	2.5V ~ 6V	-40°C ~ 85°C	Surface Mount	16-SOIC (0.295", 7.50mm Width)	16-SO
PCA9554PW,118 IC I/O EXPANDER I2C 8B 16TSSOP NXP USA Inc.	317	$1.96		Tape & Reel (TR)	Active	8	I²C, SMBus	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	2.3V ~ 5.5V	-40°C ~ 85°C	Surface Mount	16-TSSOP (0.173", 4.40mm Width)	16-TSSOP
PCA9536TK,118 IC I/O EXPANDER I2C 4B 8HVSON NXP USA Inc.	466	$1.62		Tape & Reel (TR)	Active	4	I²C, SMBus	No	POR	Push-Pull	10mA, 25mA	400 kHz	2.3V ~ 5.5V	-40°C ~ 85°C	Surface Mount	8-VFDFN Exposed Pad	8-HVSON (3x3)
PCA6408APW,118 IC I/O EXPANDER 8BIT GP 16TSSOP NXP USA Inc.	561	$1.64		Tape & Reel (TR)	Active	8	I²C, SMBus	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	1.65V ~ 5.5V	-40°C ~ 85°C	Surface Mount	16-TSSOP (0.173", 4.40mm Width)	16-TSSOP
PCAL6524EVJ ULTRA LOW-VOLTAGE TRANSLATING 24 NXP USA Inc.	380	$2.08		Tape & Reel (TR)	Active	24	I²C	Yes	POR	Open Drain, Push-Pull	-	1 MHz	1.65V ~ 5.5V	-40°C ~ 85°C	Surface Mount	36-VFBGA	36-VFBGA (2.6x2.6)
PCA6416AHF,128 IC I/O EXPANDER 16BIT 24HWQFN NXP USA Inc.	526	$1.68		Tape & Reel (TR)	Active	16	I²C, SMBus	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	1.65V ~ 5.5V	-40°C ~ 85°C	Surface Mount	24-WFQFN Exposed Pad	24-HWQFN (4x4)
PCA9539AHF,128 IC I/O EXPANDER I2C 24HWQFN NXP USA Inc.	228	$2.42		Tape & Reel (TR)	Active	16	I²C, SMBus	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	1.65V ~ 5.5V	-40°C ~ 85°C	Surface Mount	24-WFQFN Exposed Pad	24-HWQFN (4x4)
PCA9538ABSHP IC GPIO EXPANDER 8BIT 16HVQFN NXP USA Inc.	22	$1.82		Tape & Reel (TR)	Active	8	I²C, SMBus	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	1.65V ~ 5.5V	-40°C ~ 85°C	Surface Mount	16-VFQFN Exposed Pad	16-HVQFN (3x3)
PCA9500PW,118 IC I/O EXPANDER I2C 8B 16TSSOP NXP USA Inc.	14	$2.83		Tape & Reel (TR)	Active	8	I²C, SMBus	No	EEPROM, POR	Push-Pull	100µA, 25mA	400 kHz	2.5V ~ 3.6V	-40°C ~ 85°C	Surface Mount	16-TSSOP (0.173", 4.40mm Width)	16-TSSOP
PCF8574T/3,512 IC I/O EXPANDER I2C 8B 16SOIC NXP USA Inc.	185	$1.86		Tube	Active	8	I²C	Yes	POR	Push-Pull	300µA, 25mA	100 kHz	2.5V ~ 6V	-40°C ~ 85°C	Surface Mount	16-SOIC (0.295", 7.50mm Width)	16-SO
PCF8575DW IC I/O EXPANDER I2C 16B 24SOIC Texas Instruments	249	$3.40		Tube	Active	16	I²C, SMBus	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	4.5V ~ 5.5V	-40°C ~ 85°C	Surface Mount	24-SOIC (0.295", 7.50mm Width)	24-SOIC
PCA9506BS,118 IC I/O EXPANDER I2C 40B 56HVQFN NXP USA Inc.	53	$6.35		Tape & Reel (TR)	Active	40	I²C	Yes	POR	Push-Pull	10mA, 25mA	400 kHz	2.3V ~ 5.5V	-40°C ~ 85°C	Surface Mount	56-VFQFN Exposed Pad	56-HVQFN (8x8)
PCA9571GUX IC I/O EXPANDER I2C 12XQFN NXP USA Inc.	479	$1.18		Tape & Reel (TR)	Active	8	I²C	No	POR	Push-Pull	-	1 MHz	1.1V ~ 3.6V	-40°C ~ 85°C	Surface Mount	12-XFQFN	12-XQFN (2x1.7)

About I/O Expanders

What are I/O Expanders?

I/O Expanders

I/O Expanders, or Input/Output Expanders, are specialized integrated circuits designed to increase the number of input and output pins available on a microcontroller or microprocessor. They function by interfacing with the main processor through communication protocols like I2C, SPI, or GPIO, allowing for additional digital inputs and outputs without the need for a larger microcontroller. By using I/O Expanders, designers can efficiently manage multiple peripherals and sensors, optimizing the use of limited I/O resources on the main processor. This makes them invaluable in applications where space and cost constraints are critical.

Types of I/O Expanders

1. I2C I/O Expanders

I2C I/O Expanders are popular for their simplicity and ease of integration. They communicate with the host processor using the I2C protocol, which requires only two wires for communication: a data line (SDA) and a clock line (SCL). These expanders are ideal for applications where multiple devices need to be connected over a short distance, offering flexibility and scalability in design.

2. SPI I/O Expanders

SPI I/O Expanders utilize the Serial Peripheral Interface (SPI) protocol, which is known for its high-speed data transfer capabilities. They are suitable for applications requiring fast communication and are often used in systems where multiple devices need to be controlled simultaneously. SPI expanders typically require more pins than I2C expanders but offer faster data rates and are less prone to interference.

3. GPIO I/O Expanders

GPIO I/O Expanders provide additional general-purpose input/output pins to a system. They are versatile and can be used in various applications, from simple LED control to complex sensor interfacing. These expanders are often used in systems where the number of available GPIO pins on the main processor is insufficient for the required tasks.

How to choose I/O Expanders?

When selecting an I/O Expander, several key parameters should be considered:

Communication Protocol: Choose between I2C, SPI, or GPIO based on your system's communication requirements and existing infrastructure.
Number of I/O Pins: Determine the number of additional I/O pins needed for your application and select an expander that meets or exceeds this requirement.
Voltage Compatibility: Ensure the expander's operating voltage matches that of your main processor and other connected devices.
Speed and Performance: Consider the data transfer rate and latency requirements of your application, especially for time-sensitive tasks.
Package Size and Type: Evaluate the physical space available on your PCB and choose an expander with a suitable package size and type.

To evaluate product quality and reliability, review supplier datasheets, customer reviews, and industry certifications. Consider environmental factors such as temperature range and humidity, and ensure the expander is installed in a manner that minimizes exposure to adverse conditions.

Applications of I/O Expanders

1. Consumer Electronics

In consumer electronics, I/O Expanders are used to manage multiple user interfaces, such as buttons, switches, and LEDs. They enable sleek, compact designs by reducing the need for larger microcontrollers, thus saving space and cost.

2. Industrial Automation

Industrial automation systems often require extensive sensor networks and control interfaces. I/O Expanders facilitate the integration of numerous sensors and actuators, providing efficient control and monitoring capabilities in complex environments.

3. Automotive Systems

In automotive applications, I/O Expanders are used to manage various subsystems, such as lighting, infotainment, and climate control. They help streamline wiring harnesses and reduce the complexity of electronic control units (ECUs).

4. Home Automation

Home automation systems benefit from I/O Expanders by enabling the control of multiple devices, such as lighting, security systems, and HVAC units, from a central controller. This enhances the flexibility and scalability of smart home solutions.

5. Medical Devices

In medical devices, I/O Expanders are used to interface with sensors and actuators, ensuring precise control and monitoring of critical parameters. They are essential in applications where reliability and accuracy are paramount.