TCA9555 16-bit I2C I/O Expander

Texas Instruments Signal_Chain — specifications, applications, sourcing support and RFQ.

TCA9555 16-bit I2C I/O Expander

RFQ Available Sourcing Support Alternative Matching RoHS
Part Number
TCA9555
Manufacturer
Texas Instruments
Package
TSSOP-24 (PW) 7.80 mm x 4.40 mm; SSOP-24 (DB) 8.20 mm x 5.30 mm; WQFN-24 (RTW) 4.00 mm x 4.00 mm; VQFN-24 (RGE) 4.00 mm x 4.00 mm
Category
Signal Chain
Product Type
Operational Amplifier

Quick Sourcing Note

TCA9555 from Texas Instruments is a Signal_Chain 16-bit I2C I/O expander offered in TSSOP-24, SSOP-24, WQFN-24, and VQFN-24 packages. It operates from a 1.65-5.5 V supply and supports a 400 kHz fast I2C bus. The device provides two 8-bit ports for 16 total I/O bits, with ports defaulting to inputs at power-on and internal pull-up behavior for undriven inputs. It supports three hardware address pins for up to eight devices on the same I2C bus or SMBus. Typical use cases include I2C-controlled digital expansion, addressable port control, interrupt-monitored inputs, and low-standby-current systems.

Specifications

TypeDescription
Part NumberTCA9555
ManufacturerTexas Instruments
Product TypeOperational Amplifier
CategorySignal Chain
Package / CaseTSSOP-24 (PW) 7.80 mm x 4.40 mm; SSOP-24 (DB) 8.20 mm x 5.30 mm; WQFN-24 (RTW) 4.00 mm x 4.00 mm; VQFN-24 (RGE) 4.00 mm x 4.00 mm
Supply Voltage Operating Range1.65-5.5 V; recommended operating condition
Standby Current Consumption3.5 uA maximum; feature summary
I2C Bus Speed400 kHz; fast I2C bus compatible
I/O Port Count16 bits; two 8-bit ports P00-P07 and P10-P17
I/O Default StateInputs; at power-on
I/O Pull-up ResistorInternal pull-up included; pulls I/O to default high when configured as input and undriven
Address Pins3 pins; A0, A1, A2 hardware address selection
Maximum Devices on Bus8 devices; using configurable A0-A2 address pins on same I2C bus or SMBus
Interrupt OutputOpen-drain active-low INT; connect INT to VCC through pull-up resistor
I/O Port Tolerance5 V tolerant; feature summary for I/O ports
Absolute Maximum Supply Voltage-0.5 to 6 V; over operating free-air temperature range
Absolute Maximum Input Voltage-0.5 to 6 V; input negative-voltage rating may be exceeded if current rating is observed
Absolute Maximum Output Voltage-0.5 to 6 V; output voltage rating may be exceeded if current rating is observed
Input Clamp Current-20 mA; VI < 0 V
Output Clamp Current-20 mA; VO < 0 V
Input-Output Clamp Current±20 mA; VO < 0 V or VO > VCC
Continuous Output Low Current50 mA; VO = 0 to VCC, absolute maximum
Continuous Output High Current-50 mA; VO = 0 to VCC, absolute maximum
Continuous Current Through GND-250 mA; absolute maximum
Continuous Current Through VCC160 mA; absolute maximum
Maximum Junction Temperature100 °C; absolute maximum
Storage Temperature-65 to 150 °C; absolute maximum
ESD HBM Rating±2000 V; human-body model per ANSI/ESDA/JEDEC JS-001
ESD CDM Rating±1000 V; charged-device model per JESD22-C101 or ANSI/ESDA/JEDEC JS-002
High-Level Input Voltage, SCL/SDA0.7 x VCC to VCC V; recommended operating condition
High-Level Input Voltage, A2-A0 and P-ports0.7 x VCC to 5.5 V; recommended operating condition
Low-Level Input Voltage, SCL/SDA-0.5 to 0.3 x VCC V; recommended operating condition
Low-Level Input Voltage, A2-A0 and P-ports-0.5 to 0.3 x VCC V; recommended operating condition
High-Level Output Current, P-ports-10 mA; P07-P00 and P17-P10 recommended operating condition
Low-Level Output Current, P-ports25 mA; Tj <= 65°C
Low-Level Output Current, P-ports18 mA; Tj <= 85°C
Low-Level Output Current, P-ports11 mA; Tj <= 100°C
Low-Level Output Current, INT/SDA6 mA; Tj <= 85°C
Low-Level Output Current, INT/SDA3.5 mA; Tj <= 100°C
Operating Free-Air Temperature-40 to 85 °C; recommended operating condition
Thermal Resistance Junction-to-Ambient, PW108.8 °C/W; TSSOP-24 package
Thermal Resistance Junction-to-Ambient, DB92.9 °C/W; SSOP-24 package
Thermal Resistance Junction-to-Ambient, RTW43.6 °C/W; WQFN-24 package
Thermal Resistance Junction-to-Ambient, RGE48.4 °C/W; VQFN-24 package
Input Diode Clamp Voltage-1.2 V maximum; II = -18 mA, VCC = 1.65 V to 5.5 V
Power-On Reset Voltage Rising1.2 V typ, 1.5 V max; VCC rising, VI = VCC or GND, IO = 0, VCC = 1.65 V to 5.5 V
Power-On Reset Voltage Falling0.75 V typ, 1 V max; VCC falling, VI = VCC or GND, IO = 0, VCC = 1.65 V to 5.5 V
P-Port High-Level Output Voltage1.2 V minimum; IOH = -8 mA, VCC = 1.65 V
P-Port High-Level Output Voltage1.8 V minimum; IOH = -8 mA, VCC = 2.3 V
P-Port High-Level Output Voltage2.6 V minimum; IOH = -8 mA, VCC = 3 V
P-Port High-Level Output Voltage4.1 V minimum; IOH = -8 mA, VCC = 4.75 V
P-Port High-Level Output Voltage1.0 V minimum; IOH = -10 mA, VCC = 1.65 V
P-Port High-Level Output Voltage1.7 V minimum; IOH = -10 mA, VCC = 2.3 V
P-Port High-Level Output Voltage2.5 V minimum; IOH = -10 mA, VCC = 3 V
P-Port High-Level Output Voltage4.0 V minimum; IOH = -10 mA, VCC = 4.75 V
SDA Low-Level Output Current3 mA minimum; VOL = 0.4 V, VCC = 1.65 V to 5.5 V
P-Port Low-Level Output Current8 mA minimum; VOL = 0.5 V, VCC = 1.65 V to 5.5 V
P-Port Low-Level Output Current10 mA minimum; VOL = 0.7 V, VCC = 1.65 V to 5.5 V
INT Low-Level Output Current3 mA minimum; VOL = 0.4 V, VCC = 1.65 V to 5.5 V
SCL/SDA Input Leakage Current±1 uA; VI = VCC or GND, VCC = 1.65 V to 5.5 V
A2-A0 Input Leakage Current±1 uA; VI = VCC or GND, VCC = 1.65 V to 5.5 V
P-Port Input High Leakage Current1 uA maximum; VI = VCC, VCC = 1.65 V to 5.5 V
P-Port Input Low Leakage Current-100 uA maximum; VI = GND, VCC = 1.65 V to 5.5 V
Datasheet Statusrequest_only

Product Overview

The TCA9555 is a Texas Instruments 16-bit I2C I/O expander in the Signal_Chain category. It provides two 8-bit ports, P00-P07 and P10-P17, with I/O defaulting to input state at power-on. The device is fast I2C bus compatible at 400 kHz and operates across a recommended 1.65-5.5 V supply range.

Addressing is set through A0, A1, and A2 hardware address pins, allowing up to eight devices on the same I2C bus or SMBus. The port inputs include internal pull-up behavior when configured as inputs and undriven, and the I/O ports are 5 V tolerant. An open-drain active-low INT output is provided and is intended to connect to VCC through a pull-up resistor.

Package options include TSSOP-24 (PW), SSOP-24 (DB), WQFN-24 (RTW), and VQFN-24 (RGE). Thermal resistance to ambient is specified as 108.8 °C/W for PW, 92.9 °C/W for DB, 43.6 °C/W for RTW, and 48.4 °C/W for RGE. The device supports applications needing I2C-based digital I/O expansion, interrupt signaling, and multiple addressable expanders on one bus.

Key Features

  • 16-bit I2C I/O expander with two 8-bit ports
  • 1.65-5.5 V recommended operating supply range
  • 400 kHz fast I2C bus compatible interface
  • I/O ports default to inputs at power-on
  • Internal pull-up included for undriven input ports
  • Three address pins support eight bus devices
  • Open-drain active-low INT output with pull-up connection
  • 5 V tolerant I/O ports
  • 3.5 uA maximum standby current
  • -40 to 85 °C operating free-air temperature

Typical Applications

  • I2C digital I/O expansion
  • Two-port GPIO control
  • Interrupt-monitored input systems
  • Multi-device I2C bus expansion
  • Low-standby-current control nodes
  • 5 V tolerant port interfacing
  • Address-selectable SMBus peripherals

Procurement Notes

When requesting a quote for TCA9555, buyers should confirm the manufacturer, package or case, required quantity, target date code, compliance documents, packing method, destination country and expected delivery schedule.

If alternatives are acceptable, buyers should share the approved vendor list, required electrical or optical limits, package constraints and qualification requirements. Any alternative part should be reviewed by the buyer's engineering team before production use.

For analog and signal-chain sourcing, supply voltage, bandwidth, accuracy, noise level, package, temperature grade, input/output configuration and qualification requirements should be verified before approval.

FAQ

What supply voltage range does the TCA9555 support?

The TCA9555 has a recommended operating supply voltage range of 1.65-5.5 V. Absolute maximum supply voltage is specified from -0.5 to 6 V over the operating free-air temperature range.

How many I/O ports are available on the TCA9555?

The device provides 16 I/O bits arranged as two 8-bit ports, P00-P07 and P10-P17. At power-on, the I/O ports default to inputs.

How many TCA9555 devices can share one I2C bus?

Three hardware address pins, A0, A1, and A2, provide address selection. Using these configurable pins, up to eight devices can be placed on the same I2C bus or SMBus.

What package options are listed for the TCA9555?

Package options include TSSOP-24 (PW) 7.80 mm x 4.40 mm, SSOP-24 (DB) 8.20 mm x 5.30 mm, WQFN-24 (RTW) 4.00 mm x 4.00 mm, and VQFN-24 (RGE) 4.00 mm x 4.00 mm.

Technical Review & Sourcing Note

Prepared by LDeepAI Component Sourcing Team. Reviewed for RFQ, documentation and alternative sourcing use. Last updated: July 8, 2026.

This page is based on manufacturer datasheet information and LDeepAI sourcing review. Specifications should be verified against the official manufacturer datasheet before final procurement or design approval. Final electrical, optical and reliability approval should be confirmed by the buyer's engineering team.

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