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Product details

Parameters

Number of I/Os 8 Features Configuration registers, Interrupt pin Supply voltage (Min) (V) 2.3 Supply voltage (Max) (V) 5.5 Addresses 8 Rating Catalog Frequency (Max) (kHz) 400 Operating temperature range (C) -40 to 85 open-in-new Find other I2C general-purpose I/Os (GPIOs)

Package | Pins | Size

SOIC (D) 16 59 mm² 9.9 x 6 SSOP (DB) 16 48 mm² 6.2 x 7.8 TSSOP (PW) 16 22 mm² 4.4 x 5 TVSOP (DGV) 16 23 mm² 3.6 x 6.4 VQFN (RGV) 16 16 mm² 4 x 4 VQFN (RGY) 16 14 mm² 4 x 3.5 open-in-new Find other I2C general-purpose I/Os (GPIOs)

Features

  • Low Standby Current Consumption of 1 μA Max
  • I2C to Parallel Port Expander
  • Operating Power-Supply Voltage Range of 2.3 V to 5.5 V
  • 5-V Tolerant I/O Ports
  • 400-kHz Fast I2C Bus
  • Three Hardware Address Pins Allow for Use of up to Eight Devices on I2C/SMBus
  • Lower-Voltage Higher-Performance Migration Path for PCA9556
  • Input/Output Configuration Register
  • Polarity Inversion Register
  • Active-Low Reset Input
  • Internal Power-On Reset
  • High-Impedance Open Drain on P0
  • Power Up With All Channels Configured as Inputs
  • No Glitch on Power Up
  • Noise Filter on SCL/SDA Inputs
  • Latched Outputs With High Current Drive Maximum Capability for Directly Driving LEDs
  • Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
  • ESD Protection Exceeds JESD 22
    • 2000-V Human-Body Model (A114-A)
    • 200-V Machine Model (A115-A)
    • 1000-V Charged-Device Model (C101)

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Description

This 8-bit I/O expander for the two-line bidirectional bus (I2C) is designed for 2.3-V to 5.5-V VCC operation. The device provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL) and serial data (SDA)].

The PCA9557 consists of one 8-bit configuration (input or output selection), input port, output port, and polarity inversion (active-high) registers. At power on, the I/Os are configured as inputs. However, the system master can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for each input or output is kept in the corresponding input or output register. The polarity of the input port register can be inverted with the polarity inversion register. All registers can be read by the system master.

The device outputs (latched) have high-current drive capability for directly driving LEDs. The device has low current consumption.

The system master can reset the PCA9557 in the event of a timeout or other improper operation by asserting a low in the active-low reset (RESET) input. The power-on reset puts the registers in their default state and initializes the I2C/SMBus state machine. Asserting RESET causes the same reset/initialization to occur without depowering the part.

Three hardware pins (A0, A1, and A2) are used to program and vary the fixed I2C address, allowing up to eight devices to share the same I2C bus or SMBus.

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Technical documentation

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Type Title Date
* Datasheet PCA9557 Remote 8-Bit I2C and SMBus Low-Power I/O Expander datasheet (Rev. J) Jun. 12, 2014
Application notes I2C Dynamic Addressing Apr. 25, 2019
Selection guides Logic Guide (Rev. AB) Jun. 12, 2017
Application notes Choosing the Correct I2C Device for New Designs Sep. 07, 2016
Application notes Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) Dec. 02, 2015
Application notes Understanding the I2C Bus Jun. 30, 2015
Application notes Maximum Clock Frequency of I2C Bus Using Repeaters May 15, 2015
Application notes I2C Bus Pull-Up Resistor Calculation Feb. 13, 2015
Application notes Programming Fun Lights With TI's TCA6507 Nov. 30, 2007
Application notes Semiconductor Packing Material Electrostatic Discharge (ESD) Protection Jul. 08, 2004

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Design tools & simulation

SIMULATION TOOLS Download
PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Features
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)
SIMULATION TOOLS Download
SPICE-based analog simulation program
TINA-TI TINA-TI provides all the conventional DC, transient and frequency domain analysis of SPICE and much more. TINA has extensive post-processing capability that allows you to format results the way you want them. Virtual instruments allow you to select input waveforms and probe circuit nodes voltages (...)
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DESIGN TOOLS Download
I2C designer tool
I2C-DESIGNER — Use the I2C Designer tool to quickly resolve conflicts in addressing, voltage level and frequency in I2C based designs. Enter master and slave inputs to automatically generate an I2C tree or easily build a custom solution. This tool will help designers save time and comply with the I2C standard with (...)
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Reference designs

REFERENCE DESIGNS Download
Reference Design for 6-Cell EV/HEV Integrated Battery Monitor and Protector w/Passive Balancing
TIDA-00821 The TIDA-00821 reference design is a stackable monitor and protector for use in large format Lithium-ion batteries that provides monitoring, balancing, and communications. Each bq76PL536A-Q1 EVM can manage 3 to 6 cells  for Li-ion battery applications. Up to 32 bq76PL536A-Q1 EVM modules can be (...)
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CAD/CAE symbols

Package Pins Download
SOIC (D) 16 View options
SSOP (DB) 16 View options
TSSOP (PW) 16 View options
TVSOP (DGV) 16 View options
VQFN (RGV) 16 View options
VQFN (RGY) 16 View options

Ordering & quality

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