PCA9539DB Equivalent & Substitute Parts

Part Overview

The PCA9539DB is a 16-bit I/O Expander designed for I2C and SMBus communication at 400 kHz, manufactured by Texas Instruments in a 24-SSOP surface mount package. This device is classified as Last Time Buy, indicating discontinued production with limited inventory availability. The PCA9539DB operates across a supply voltage range of 2.3V to 5.5V and supports operating temperatures from -40°C to 85°C, making it suitable for industrial and commercial applications requiring expanded digital I/O capabilities.

Due to its Last Time Buy status and limited stock of 873 pieces, identifying functionally equivalent substitute parts is essential for long-term design continuity and supply chain reliability.

Substiute Parts

PCA9539DB

Texas InstrumentsIn Stock: 903PCA9539DB Datasheet

Current PartRFQ

TCA9539PWR

Texas InstrumentsIn Stock: 61089TCA9539PWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PCA9539DB is determined by the following critical parameters:

• I/O Count: Must be 16 bits
• Interface Protocol: Must support I2C and SMBus at 400 kHz
• Output Configuration: Must be Push-Pull type with 10mA and 25mA source/sink capability
• Interrupt Support: Must include interrupt output functionality
• Voltage Compatibility: Supply voltage range must encompass or be compatible with 2.3V ~ 5.5V
• Package Type: Surface mount configuration required; package footprint differences are acceptable if electrical characteristics align
• Environmental Compliance: RoHS3 compliance and REACH unaffected status required

The TCA9539PWR meets all substitution criteria while offering improved supply voltage flexibility (1.65V ~ 5.5V) and Active product status with significantly higher inventory availability.

Parameter Comparison

Engineering Selection Recommendations

The TCA9539PWR is the manufacturer-recommended substitute for the PCA9539DB. Both devices are manufactured by Texas Instruments and maintain identical electrical specifications for I/O count, interface protocol, clock frequency, output characteristics, and operating temperature range.

The primary distinction is package format: the PCA9539DB uses 24-SSOP (0.209" width), while the TCA9539PWR uses 24-TSSOP (0.173" width). This footprint difference requires PCB layout modification but does not affect electrical functionality or protocol compatibility.

The TCA9539PWR offers superior supply voltage flexibility with a lower minimum threshold of 1.65V compared to the PCA9539DB's 2.3V minimum, enabling operation in additional low-voltage applications. Both devices maintain ROHS3 compliance and REACH unaffected status.

The TCA9539PWR's Active product status and substantially higher inventory (60988 pieces) provide long-term supply chain security and design continuity advantages over the Last Time Buy PCA9539DB.

Frequently Asked Questions (FAQ)

Q: Can the TCA9539PWR directly replace the PCA9539DB without firmware changes?

A: Yes. Both devices implement identical I2C/SMBus protocols, register maps, and electrical interfaces. No firmware or software modifications are required. The substitution is electrically transparent at the protocol level.

Q: What is the primary difference between these two parts?

A: The package footprint differs. The PCA9539DB uses 24-SSOP (0.209" width), while the TCA9539PWR uses 24-TSSOP (0.173" width). PCB layout and component placement must be adjusted accordingly. Electrical specifications remain identical.

Q: Is the TCA9539PWR compatible with designs specified for 2.3V minimum supply voltage?

A: Yes. The TCA9539PWR operates from 1.65V to 5.5V, which encompasses the PCA9539DB's 2.3V to 5.5V range. Designs operating at 2.3V or higher will function identically with the TCA9539PWR.

Q: Why is the PCA9539DB classified as Last Time Buy?

A: Last Time Buy status indicates Texas Instruments has discontinued production of this part number. The TCA9539PWR represents the active product line continuation with equivalent functionality and improved availability.

Q: Are both parts RoHS3 compliant?

A: Yes. Both the PCA9539DB and TCA9539PWR are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements.

Q: What inventory considerations should guide part selection?

A: The PCA9539DB has 873 pieces available. The TCA9539PWR has 60988 pieces in stock. For new designs or long-term production, the TCA9539PWR is recommended due to superior supply availability and Active product status.