PCA9554DB Equivalent & Substitute Parts

Part Overview

The PCA9554DB is an 8-bit I/O Expander designed for I2C and SMBus communication at 400 kHz, manufactured by Texas Instruments in a 16-SSOP surface mount package. This device provides push-pull output capability with interrupt functionality and power-on reset (POR) features, operating across a supply voltage range of 2.3V to 5.5V and temperature range of -40°C to 85°C.

The PCA9554DB is currently in Last Time Buy status, indicating end-of-life production. Identifying equivalent substitute parts is necessary to ensure design continuity and maintain component availability for ongoing production and maintenance requirements.

Substiute Parts

PCA9554DB

Texas InstrumentsIn Stock: 2185PCA9554DB Datasheet

Current PartRFQ

TCA9554DBR

Texas InstrumentsIn Stock: 64463TCA9554DBR Datasheet

MFR RecommendedRFQ

TCA9554PWR

Texas InstrumentsIn Stock: 42237TCA9554PWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the PCA9554DB is determined by the following critical parameters: 8-bit I/O count, I2C/SMBus interface support, 400 kHz clock frequency, push-pull output configuration, interrupt capability, and compatible package footprint. The supply voltage range and output current specifications define the operational envelope within which substitutes must function.

Two primary substitute parts are identified:

TCA9554DBR – Direct package equivalent (16-SSOP) with identical I/O configuration, interface protocol, and clock frequency. Voltage supply range extends to 1.65V minimum, providing broader low-voltage compatibility. Output current specifications are not specified in available data.

TCA9554PWR – Functional equivalent with identical I/O, interface, and clock specifications, but in 16-TSSOP package (0.173" width versus 0.209" for SSOP). Voltage supply range extends to 1.65V minimum. Output current matches the original specification (10mA, 25mA).

Parameter Comparison

Engineering Selection Recommendations

TCA9554DBR is the preferred substitute when PCB layout constraints require the 16-SSOP package footprint. This part maintains identical package dimensions and pinout compatibility with the PCA9554DB, eliminating the need for PCB redesign. The extended lower voltage limit (1.65V) provides additional operational flexibility. Both parts are ROHS3 compliant and carry identical regulatory certifications (REACH Unaffected, EAR99 ECCN classification).

TCA9554PWR is suitable for applications where package size optimization is acceptable. The 16-TSSOP package provides a smaller footprint (0.173" width) while maintaining full functional compatibility. This part explicitly specifies output current ratings matching the original device and supports both I2C and SMBus protocols. Selection of this part requires PCB layout modification to accommodate the different package dimensions.

Both substitutes are in Active product status with significantly higher inventory availability compared to the Last Time Buy PCA9554DB, ensuring long-term supply chain stability.

Frequently Asked Questions (FAQ)

Q: Can TCA9554DBR be used as a direct replacement for PCA9554DB without PCB modification?

A: Yes. The TCA9554DBR maintains identical 16-SSOP package dimensions, pinout, and electrical interface specifications. No PCB layout changes are required for this substitution.

Q: What is the primary difference between TCA9554DBR and TCA9554PWR?

A: The primary difference is package type. TCA9554DBR uses 16-SSOP (0.209" width), while TCA9554PWR uses 16-TSSOP (0.173" width). Both provide identical I/O functionality and interface protocols. TCA9554PWR requires PCB redesign due to different package footprint.

Q: Are there voltage supply compatibility concerns when substituting with TCA9554DBR or TCA9554PWR?

A: Both substitutes support the full 2.3V to 5.5V operating range of the original PCA9554DB. The extended lower limit (1.65V) of the substitutes provides additional margin for low-voltage applications. No voltage compatibility issues exist for designs operating within the original specification range.

Q: Do the substitute parts support SMBus protocol?

A: TCA9554PWR explicitly supports both I2C and SMBus at 400 kHz. TCA9554DBR specifies I2C interface; SMBus compatibility is not documented in available parameters. For applications requiring SMBus protocol support, TCA9554PWR is the confirmed substitute.

Q: What are the output current specifications for TCA9554DBR?

A: Output current specifications are not provided in available technical data for TCA9554DBR. For applications requiring confirmed 10mA/25mA output current ratings, TCA9554PWR is the specified substitute.

Q: Are both substitute parts RoHS compliant?

A: Yes. Both TCA9554DBR and TCA9554PWR are ROHS3 compliant with identical regulatory certifications (REACH Unaffected, EAR99 ECCN) as the original PCA9554DB.