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PCF8574A

ACTIVE

8-bit 2.5- to 5.5-V I2C/SMBus I/O expander with interrupt

Product details

Number of I/Os 8 Features Interrupt pin Supply voltage (min) (V) 2.5 Supply voltage (max) (V) 6 Addresses 8 Rating Catalog Frequency (max) (MHz) 0.1 Operating temperature range (°C) -40 to 85
Number of I/Os 8 Features Interrupt pin Supply voltage (min) (V) 2.5 Supply voltage (max) (V) 6 Addresses 8 Rating Catalog Frequency (max) (MHz) 0.1 Operating temperature range (°C) -40 to 85
PDIP (N) 16 181.42 mm² 19.3 x 9.4 SOIC (DW) 16 106.09 mm² 10.3 x 10.3 TSSOP (PW) 20 41.6 mm² 6.5 x 6.4 VQFN (RGY) 20 15.75 mm² 4.5 x 3.5
  • Low standby-current consumption of 10 µA max
  • I2C to parallel-port expander
  • Open-drain interrupt output
  • Compatible with most microcontrollers
  • Latched outputs with high-current drive capability for directly driving LEDs
  • Latch-up performance exceeds 100 mA Per JESD 78, Class II
  • Low standby-current consumption of 10 µA max
  • I2C to parallel-port expander
  • Open-drain interrupt output
  • Compatible with most microcontrollers
  • Latched outputs with high-current drive capability for directly driving LEDs
  • Latch-up performance exceeds 100 mA Per JESD 78, Class II

This 8-bit input/output (I/O) expander for the two-line bidirectional bus (I2C) is designed for 2.5-V to 6-V VCC operation.

The PCF8574A device provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL), serial data (SDA)].

The device features an 8-bit quasi-bidirectional I/O port (P0–P7), including latched outputs with high-current drive capability for directly driving LEDs. Each quasi-bidirectional I/O can be used as an input or output without the use of a data-direction control signal. At power on, the I/Os are high. In this mode, only a current source to VCC is active.

This 8-bit input/output (I/O) expander for the two-line bidirectional bus (I2C) is designed for 2.5-V to 6-V VCC operation.

The PCF8574A device provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL), serial data (SDA)].

The device features an 8-bit quasi-bidirectional I/O port (P0–P7), including latched outputs with high-current drive capability for directly driving LEDs. Each quasi-bidirectional I/O can be used as an input or output without the use of a data-direction control signal. At power on, the I/Os are high. In this mode, only a current source to VCC is active.

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Technical documentation

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Type Title Date
* Data sheet PCF8574A Remote 8-Bit I/O Expander for I2C Bus datasheet (Rev. G) PDF | HTML 02 Aug 2021
Application note I2C Dynamic Addressing 25 Apr 2019
Application note Choosing the Correct I2C Device for New Designs PDF | HTML 07 Sep 2016
Application note Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) 02 Dec 2015
Application note Understanding the I2C Bus PDF | HTML 30 Jun 2015
Application note Maximum Clock Frequency of I2C Bus Using Repeaters 15 May 2015
Application note I2C Bus Pull-Up Resistor Calculation PDF | HTML 13 Feb 2015
Application note Programming Fun Lights With TI's TCA6507 30 Nov 2007
More literature PCF8574 and PCF8574A Application Clip 18 Aug 2004
More literature I2C Application Clip 19 Jul 2004
Application note Semiconductor Packing Material Electrostatic Discharge (ESD) Protection 08 Jul 2004
More literature I2C and Serial Bus Devices Application Clip 10 Jul 2003
Application note Improving System Interrupt Management Using the PCF8574 and PCF8574A I/O Expande 27 Jul 2001

Design & development

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Simulation model

PCF8574A IBIS Model

SCEM498.ZIP (47 KB) - IBIS Model
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Reference designs

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Design guide: PDF
Schematic: PDF
Package Pins Download
PDIP (N) 16 View options
SOIC (DW) 16 View options
TSSOP (PW) 20 View options
VQFN (RGY) 20 View options

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