Firmware
TCA9555
16-bit 1.65- to 5.5-V I2C/SMBus I/O expander with interrupt, weak pull-up & config registers
Data sheet
TCA9555
- Low Standby-Current Consumption of 3.5 µA Maximum
- I2C to Parallel Port Expander
- Open-Drain Active-Low Interrupt Output
- 5-V Tolerant I/O Ports
- Compatible With Most Microcontrollers
- 400-kHz Fast I2C Bus
- Configurable Slave Address with 3 Address Pins
- Polarity Inversion Register
- Latched Outputs With High-Current Drive 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)
- 1000-V Charged-Device Model (C101)
This 16-bit I/O expander for the two-line bidirectional bus (I2C) is designed for 1.65-V to 5.5-V VCC operation. It provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface.
The TCA9555 consists of two 8-bit Configuration (input or output selection), Input Port, Output Port, and Polarity Inversion (active high or active low operation) registers. At power on, the I/Os are configured as inputs. 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.
The TCA9555 is identical to the TCA9535, except for the inclusion of the internal I/O pull-up resistor, which pulls the I/O to a default high when configured as an input and undriven.
Three hardware pins (A0, A1, and A2) are used to program the I2C address, which allows up to eight TCA9555 devices to share the same I2C bus or SMBus. The fixed I2C address of the TCA9555 is the same as the PCF8575, PCF8575C, and PCF8574, allowing up to eight of these devices in any combination to share the same I2C bus or SMBus.
Technical documentation
No results found. Please clear your search and try again.
View all 9 | Type | Title | Date | ||
|---|---|---|---|---|
| * | Data sheet | TCA9555 Low-Voltage 16-Bit I2C and SMBus I/O Expander with Interrupt Output and Configuration Registers datasheet (Rev. E) | PDF | HTML | 01 Apr 2019 |
| Application note | How to Configure an I2C Push-Pull IO Expander to Operate as Open Drain | PDF | HTML | 17 Jul 2024 | |
| Application note | I2C: What is the Auto Increment Feature? | PDF | HTML | 05 Jul 2024 | |
| Application note | Understanding Transient Drive Strength vs. DC Drive Strength in Level-Shifters (Rev. A) | PDF | HTML | 03 Jul 2024 | |
| 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 the I2C Bus | PDF | HTML | 30 Jun 2015 | |
| Application note | I2C Bus Pull-Up Resistor Calculation | PDF | HTML | 13 Feb 2015 | |
| EVM User's guide | I/O Expander EVM User's Guide (Rev. A) | 25 Jul 2014 |
Design & development
For additional terms or required resources, click any title below to view the detail page where available.
Evaluation board
IO-EXPANDER-EVM — IO-EXPANDER-EVM: I2C and SMBus IO Expander Evaluation Module
The IO expander evaluation module (EVM) lets you evaluate TI's portfolio of SMBus and I2C IO expander line devices. The TCA6424A and TCA9539 come installed on the board. The 24-pin TSSOP footprint also supports TCA6408A, TCA6416A, TCA9534, TCA9534A, TCA9535, TCA9538, TCA9554, TCA9554A and TCA9555.
User guide: PDF
Design tool
I2C-DESIGNER — I2C designer tool
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 (...)
Simulation tool
PSPICE-FOR-TI — PSpice® for TI design and simulation tool
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 (...)
Simulation tool
TINA-TI — SPICE-based analog simulation program
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 (...)
User guide: PDF
| Package | Pins | CAD symbols, footprints & 3D models |
|---|---|---|
| SSOP (DB) | 24 | Ultra Librarian |
| TSSOP (PW) | 24 | Ultra Librarian |
| VQFN (RGE) | 24 | Ultra Librarian |
| WQFN (RTW) | 24 | Ultra Librarian |
Ordering & quality
Information included:
- RoHS
- REACH
- Device marking
- Lead finish/Ball material
- MSL rating/Peak reflow
- MTBF/FIT estimates
- Material content
- Qualification summary
- Ongoing reliability monitoring
Information included:
- Fab location
- Assembly location
Recommended products may have parameters, evaluation modules or reference designs related to this TI product.
Support & training
TI E2E™ forums with technical support from TI engineers
Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.
If you have questions about quality, packaging or ordering TI products, see TI support.