PCF8574APW Texas Instruments io-expanders (TSSOP-20) In Stock
PCF8574APW is an 8-bit I2C I/O expander by Texas Instruments, supporting 2.5V to 6V supply and 400kHz Fast-mode I2C. From $0.90/unit, in-stock, 1-piece MOQ, worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- TSSOP-20
- Pin Count
- 20
- Lifecycle
- ACTIVE
- Datasheet
- PCF8574APW Datasheet PDF
- Category
- io-expanders
- Price
- From $0.8988(MOQ 1)
- Temp Range
- -40.0°C to 85.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
What is PCF8574APW used for?
Widely used in embedded systems to expand GPIO on microcontrollers for driving LEDs, keypads, and relay boards. Also found in industrial HMI panels, home automation controllers, and smart meter display modules where I2C bus GPIO extension is needed.
What are the specifications of PCF8574APW?
| supplyVoltage | 2.5V to 6V |
| interface | I2C / SMBus |
| maxClockFrequency | 400 kHz |
| ioPins | 8 |
| operatingTemperature | -40 to +85 |
| packageType | TSSOP-20 |
| pitch | 0.65 mm |
| addressableDevices | 8 per bus |
| interruptOutput | Yes (active-low) |
| Package | TSSOP-20 |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
Where can I find the PCF8574APW datasheet?
PCF8574APW Datasheet DownloadOfficial datasheet from Texas Instruments
What are equivalent replacements for PCF8574APW?
Compatible alternatives and drop-in replacements for PCF8574APW:
Same 8-bit I2C I/O expander, different I2C address range (0x20-0x27 vs 0x38-0x3F)
8-bit I2C I/O expander with open-drain interrupt, 1.65V to 5.5V, TSSOP-16
Frequently Asked Questions
What is the PCF8574APW and what does it do?
The PCF8574APW is an 8-bit I2C-bus I/O port expander from Texas Instruments. It connects to a microcontroller via a 2-wire I2C interface (SDA/SCL) and provides 8 quasi-bidirectional I/O pins that can individually read or drive digital signals. It operates from 2.5V to 6V and supports I2C speeds up to 400kHz, making it ideal for expanding GPIO when a microcontroller runs out of I/O pins.
How many PCF8574APW devices can I connect to the same I2C bus?
Up to 8 PCF8574APW devices can share the same I2C bus. The device features 3 hardware address pins (A0, A1, A2), each tied high or low to set a unique 7-bit I2C address, giving 8 possible addresses. With 8 devices you can control up to 64 independent I/O pins over just 2 wires.
What is the difference between PCF8574APW and PCF8574PW?
Both are 8-bit I2C I/O expanders in the TSSOP-20 package. The key difference is the I2C base address range: PCF8574A (suffix A) uses addresses 0x38 to 0x3F, while PCF8574 (no A suffix) uses 0x20 to 0x27. This lets you mix both variants on one bus for up to 16 expander devices (128 I/O pins) simultaneously.
What supply voltage and logic levels does the PCF8574APW support?
The PCF8574APW operates from 2.5V to 6V. Its I/O pins are quasi-bidirectional with internal pull-ups, and logic levels track the supply voltage, making it compatible with both 3.3V and 5V microcontrollers without level-shifting in most designs.
What are the typical applications for the PCF8574APW?
Common applications include GPIO expansion for MCUs driving LED arrays, 4x4 keypads, relay modules, and LCD displays; industrial control panels requiring isolated I/O; home automation nodes; smart meters and energy monitors; and any battery-powered design where minimizing microcontroller I/O pin count reduces system cost.
Related Guides
CSD87313DMS Synchronous Buck Power Stage Design Guide
Design a compact CSD87313DMS synchronous buck stage with practical guidance for loss, gate drive, PCB layout, EMI, thermal validation, and sourcing.
Aug 6, 2026
STEF05SGR eFuse Selection Guide for 5 V Overcurrent Protection
Choose STEF05SGR for 5 V overcurrent protection by checking current-limit margin, inrush, thermal loss, fault response, and sourcing.
Aug 6, 2026
C0402C103K3RACTU Selection Guide: Choosing a 10 nF 0402 MLCC
Select C0402C103K3RACTU by voltage margin, X7R behavior, tolerance, 0402 assembly risk, and qualified alternatives.
Aug 4, 2026
STM32H753VIT6 MCU Selection Guide: Memory, Package, Connectivity, and Security
Choose STM32H753VIT6 by evaluating memory architecture, LQFP-100 pin fit, connectivity, security, power, and sourcing tradeoffs.
Aug 4, 2026
Why Buy from FindMyChip
About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
More from Texas Instruments
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 1+ | $3.7500 | $3.75 |
| 9+ | $2.7500 | $24.75 |
| 28+ | $2.5000 | $70.00 |
| 195+ | $1.0370 | $202.21 |
| 250+ | $1.0025 | $250.63 |
| 335+ | $0.8988 | $301.10 |
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“FindMyChip sourced our entire STM32 BOM in 48 hours when our usual distributor had 16-week lead times.”