PCA9555PWR I/O Expander 16 I2C SMBus 400 kHz Equivalent & Substitute Parts

Part Overview

The PCA9555PWR is a 16-bit I/O expander IC manufactured by Texas Instruments, designed for I2C and SMBus communication at 400 kHz clock frequency in a 24-TSSOP surface mount package. This part is classified as Not For New Designs, indicating it has been superseded in the manufacturer's product line. Finding equivalent and substitute parts is necessary for ongoing production support, legacy system maintenance, and design flexibility when the primary part becomes unavailable or when alternative sourcing is required.

Substiute Parts

PCA9555PWR

Texas InstrumentsIn Stock: 29853PCA9555PWR Datasheet

Current PartRFQ

TCA9555PWR

Texas InstrumentsIn Stock: 55618TCA9555PWR Datasheet

MFR RecommendedRFQ

CAT9555YI-T2

onsemiIn Stock: 29222CAT9555YI-T2 Datasheet

MFR RecommendedRFQ

MAX7311AUG+

Analog Devices Inc./Maxim IntegratedIn Stock: 2171MAX7311AUG+ Datasheet

MFR RecommendedRFQ

MAX7312AUG+T

Analog Devices Inc./Maxim IntegratedIn Stock: 4753MAX7312AUG+T Datasheet

MFR RecommendedRFQ

PCA9535APW,118

NXP USA Inc.In Stock: 100216PCA9535APW,118 Datasheet

MFR RecommendedRFQ

PCA9535PW,118

NXP USA Inc.In Stock: 4174PCA9535PW,118 Datasheet

MFR RecommendedRFQ

PCA9555APW,118

NXP USA Inc.In Stock: 3147PCA9555APW,118 Datasheet

MFR RecommendedRFQ

PCA9555PW,118

NXP USA Inc.In Stock: 52925PCA9555PW,118 Datasheet

MFR RecommendedRFQ

PI4IOE5V9555LEX

Diodes IncorporatedIn Stock: 3245PI4IOE5V9555LEX Datasheet

MFR RecommendedRFQ

XRA1201PIG24TR-F

MaxLinear, Inc.In Stock: 7937XRA1201PIG24TR-F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PCA9555PWR is determined by strict alignment of the following electrical and mechanical parameters:

Critical Matching Parameters:

• Number of I/O: 16 bits
• Interface: I2C and/or SMBus protocol support
• Clock Frequency: 400 kHz minimum
• Package: 24-TSSOP form factor
• Mounting: Surface Mount
• RoHS Compliance: ROHS3 or equivalent

Voltage Supply Compatibility: Substitutes must support the PCA9555PWR operating range of 2.3V ~ 5.5V, or a range that fully encompasses this specification.

Output Characteristics: Push-Pull output type with current sourcing/sinking capability of minimum 10mA source and 25mA sink is the baseline requirement.

Temperature Range: Operating temperature of -40°C ~ 85°C is the baseline; substitutes with extended ranges (such as -40°C ~ 125°C) are acceptable.

Substitutes are grouped into two categories: direct equivalents from the same manufacturer (Texas Instruments) and cross-manufacturer alternatives that meet all electrical and mechanical criteria.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Highest Compatibility):

TCA9555PWR from Texas Instruments is the recommended primary substitute. It maintains identical electrical specifications to the PCA9555PWR with the exception of an extended lower voltage supply limit (1.65V vs. 2.3V), and carries Active product status. This part is sourced from the same manufacturer and ensures design continuity.

PCA9555APW,118 and PCA9555PW,118 from NXP USA Inc. are functionally equivalent alternatives with Active status. Both support the full I2C and SMBus protocol stack and maintain identical I/O count, clock frequency, and output characteristics. The voltage supply range extends to 1.65V on the APW variant, providing additional design flexibility.

Secondary Substitutes (Conditional Compatibility):

CAT9555YI-T2 from onsemi meets all critical electrical and mechanical parameters with Active product status. The output sink current specification is marginally reduced (24mA vs. 25mA), which is acceptable for most applications within the PCA9555PWR's design envelope.

MAX7311AUG+ and MAX7312AUG+T from Analog Devices Inc./Maxim Integrated provide enhanced current sourcing and sinking capability (31mA source, 43mA sink) and extended operating temperature range (-40°C ~ 125°C). These parts are suitable for applications requiring higher output drive capability or wider temperature operation.

PCA9535APW,118 and PCA9535PW,118 from NXP USA Inc. are compatible I/O expanders with identical functional specifications. These parts are interchangeable in applications where the base product number difference does not impose design constraints.

Limited Compatibility Substitutes:

PI4IOE5V9555LEX from Diodes Incorporated supports I2C protocol and meets package and frequency requirements. However, output type and current specifications are not provided in the datasheet documentation, requiring design verification before implementation.

XRA1201PIG24TR-F from MaxLinear, Inc. operates with a reduced voltage supply range (1.65V ~ 3.6V) and employs Open Drain output topology rather than Push-Pull. This part is suitable only for applications operating within the 1.65V ~ 3.6V envelope and where Open Drain output characteristics are compatible with the system design.

Compliance and Certification:

All recommended substitutes maintain ROHS3 compliance or equivalent RoHS certification status. All parts carry REACH Unaffected or REACH Compliant status. ECCN classification remains EAR99 across all substitutes, and HTSUS tariff classification is consistent at 8542.39.0001.

Frequently Asked Questions (FAQ)

Q: Can TCA9555PWR be used as a direct replacement for PCA9555PWR?

A: Yes. TCA9555PWR is a direct functional equivalent from Texas Instruments with Active product status. The extended lower voltage supply limit (1.65V vs. 2.3V) provides additional design flexibility. All other electrical and mechanical parameters are identical.

Q: What is the difference between PCA9555 and PCA9535 variants?

A: Both are 16-bit I/O expanders with identical I2C/SMBus interface, clock frequency, and package specifications. The primary difference lies in internal register architecture and addressing schemes. Substitution between these families requires design verification to confirm register compatibility with existing firmware or control logic.

Q: Are the NXP PCA9555 variants (APW,118 and PW,118) interchangeable?

A: Both PCA9555APW,118 and PCA9555PW,118 are functionally equivalent. The APW variant supports a lower voltage supply minimum (1.65V vs. 2.3V). Selection depends on the system's minimum operating voltage requirement.

Q: Can MAX7311AUG+ or MAX7312AUG+T be used in place of PCA9555PWR?

A: Yes, with design considerations. These Maxim Integrated parts provide higher output current capability (31mA source, 43mA sink vs. 10mA, 25mA) and extended temperature range (-40°C ~ 125°C). They are suitable for applications requiring enhanced drive capability or wider temperature operation. Firmware compatibility should be confirmed.

Q: What is the significance of the Open Drain output on XRA1201PIG24TR-F?

A: The XRA1201PIG24TR-F uses Open Drain output topology, which differs from the Push-Pull output of the PCA9555PWR. Open Drain outputs require external pull-up resistors and are suitable for applications where multiple devices share a common bus. This part is not a direct replacement unless the system design accommodates Open Drain characteristics.

Q: Does the reduced voltage range of XRA1201PIG24TR-F (1.65V ~ 3.6V) limit its use?

A: Yes. The XRA1201PIG24TR-F operates only within 1.65V ~ 3.6V, which excludes applications requiring 5V operation. This part is suitable only for low-voltage systems and is not a general-purpose substitute for the PCA9555PWR.

Q: Are all substitutes available in the same packaging format?

A: All listed substitutes use the 24-TSSOP surface mount package with identical physical dimensions (0.173", 4.40mm Width). However, packaging options (Cut Tape, Digi-Reel, Tape & Reel, Tube) vary by manufacturer and part number. Confirm packaging availability with your supplier for production requirements.

Q: What compliance certifications apply to all substitutes?

A: All substitutes maintain ROHS3 compliance or equivalent RoHS certification. All parts carry REACH Unaffected or REACH Compliant status. ECCN classification is EAR99 for all parts, and HTSUS tariff classification is 8542.39.0001 across all substitutes.

Q: Why is PCA9555PWR marked as Not For New Designs?

A: This designation indicates the part has been superseded by newer alternatives in the manufacturer's product line. For new designs, TCA9555PWR or equivalent active-status alternatives are recommended. Existing designs using PCA9555PWR can continue production using available inventory or approved substitutes.