PCA9538DW Equivalent & Substitute Parts

Part Overview

The PCA9538DW is an 8-bit I/O expander designed for I2C and SMBus communication at 400 kHz, packaged in a 16-SOIC surface mount configuration. This device provides push-pull output capability with interrupt functionality and power-on reset (POR) features. The PCA9538DW is currently in Last Time Buy status, making identification of functionally equivalent alternatives essential for ongoing design support and procurement planning.

Substiute Parts

PCA9538DW

Texas InstrumentsIn Stock: 947PCA9538DW Datasheet

Current PartRFQ

TCA9538PWR

Texas InstrumentsIn Stock: 2342TCA9538PWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PCA9538DW is determined by the following critical parameters:

• I/O Count: Must be 8 bits
• Interface Protocol: Must support I2C at 400 kHz minimum
• Output Configuration: Must be push-pull type
• Interrupt Capability: Must include interrupt output functionality
• Operating Temperature Range: Must cover -40°C ~ 85°C
• Supply Voltage Compatibility: Must operate within overlapping voltage ranges
• Package Compatibility: Physical form factor and pin count must match or be compatible with board layout

The TCA9538PWR meets these substitution criteria while offering an active product status and extended supply voltage range (1.65V ~ 5.5V), providing greater flexibility for low-voltage applications.

Parameter Comparison

Engineering Selection Recommendations

The TCA9538PWR is the primary substitute for the PCA9538DW based on the following factors:

Functional Equivalence: Both devices provide identical I/O count (8), interface protocol (I2C at 400 kHz), output configuration (push-pull), and interrupt functionality. Operating temperature ranges are identical.

Supply Voltage Advantage: The TCA9538PWR supports a lower minimum supply voltage (1.65V versus 2.3V), enabling use in low-power applications while maintaining full compatibility with 5.5V maximum ratings.

Product Status: The TCA9538PWR maintains active manufacturing status, ensuring long-term availability and supply chain stability compared to the PCA9538DW's Last Time Buy designation.

Compliance Alignment: Both devices are ROHS3 compliant and carry identical REACH and ECCN classifications, meeting regulatory requirements without modification.

Package Consideration: The TCA9538PWR uses 16-TSSOP packaging instead of 16-SOIC. While physically different, both are 16-pin surface mount packages with identical pin configurations, requiring PCB layout adjustment but no functional redesign.

Frequently Asked Questions (FAQ)

Q: Can the TCA9538PWR directly replace the PCA9538DW on an existing PCB?

A: The TCA9538PWR is functionally equivalent but uses a different package (16-TSSOP versus 16-SOIC). Direct socket replacement is not possible without PCB modification. However, the pin configuration is identical, allowing straightforward layout redesign for new production runs.

Q: What is the key difference between the PCA9538DW and TCA9538PWR?

A: The primary differences are product status and supply voltage range. The TCA9538PWR is actively manufactured with extended low-voltage capability (1.65V minimum), while the PCA9538DW is in Last Time Buy status with a 2.3V minimum supply voltage.

Q: Are there any interface protocol differences between these parts?

A: The PCA9538DW supports both I2C and SMBus protocols at 400 kHz. The TCA9538PWR supports I2C at 400 kHz. Both are compatible with standard I2C bus implementations. SMBus is a subset of I2C, so I2C-only devices function in SMBus applications.

Q: Do both parts require the same firmware or software configuration?

A: Both devices share the same base product number (PCA9538 and TCA9538 respectively) and identical functional specifications. Register maps and command structures are compatible, requiring no firmware changes for substitution.

Q: What packaging options are available for each part?

A: The PCA9538DW is supplied in 16-SOIC packaging. The TCA9538PWR is available in 16-TSSOP packaging with Cut Tape and Digi-Reel options. Both are surface mount configurations with identical pin counts and electrical characteristics.

Q: Are there inventory or lead time considerations?

A: The TCA9538PWR has significantly higher inventory availability (2300 pcs) compared to the PCA9538DW (887 pcs), with active manufacturing status ensuring continued supply. The PCA9538DW's Last Time Buy status indicates limited future availability.