PCA9534ADWR Equivalent & Substitute Parts

Part Overview

The PCA9534ADWR is an 8-bit I/O expander interface circuit manufactured by Texas Instruments, designed for I2C and SMBus communication at 400 kHz. This device is classified as Last Time Buy, indicating discontinued production with limited inventory availability. Finding equivalent and substitute parts is necessary to ensure design continuity and long-term component sourcing for applications requiring 8-bit parallel I/O expansion over I2C or SMBus protocols.

Substiute Parts

PCA9534ADWR

Texas InstrumentsIn Stock: 3323PCA9534ADWR Datasheet

Current PartRFQ

TCA9534ADWR

Texas InstrumentsIn Stock: 3016TCA9534ADWR Datasheet

MFR RecommendedRFQ

MAX7328AWE+

Analog Devices Inc./Maxim IntegratedIn Stock: 724MAX7328AWE+ Datasheet

MFR RecommendedRFQ

MAX7329AWE+

Analog Devices Inc./Maxim IntegratedIn Stock: 1206MAX7329AWE+ Datasheet

MFR RecommendedRFQ

MAX7329AWE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 1106MAX7329AWE+T Datasheet

MFR RecommendedRFQ

PCA9534D,118

NXP USA Inc.In Stock: 4206PCA9534D,118 Datasheet

MFR RecommendedRFQ

PCF8574AT/3,518

NXP SemiconductorsIn Stock: 17634PCF8574AT/3,518 Datasheet

MFR RecommendedRFQ

PCF8574T/3,512

NXP USA Inc.In Stock: 2237PCF8574T/3,512 Datasheet

MFR RecommendedRFQ

PCF8574T/3,518

NXP USA Inc.In Stock: 2285PCF8574T/3,518 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PCA9534ADWR is determined by the following critical parameters:

Primary Compatibility Criteria:

• Number of I/O: 8 bits (mandatory)
• Package Type: 16-SOIC form factor (mandatory for direct PCB compatibility)
• Interface Protocol: I2C or SMBus (mandatory for communication compatibility)
• Interrupt Output: Yes (required for interrupt-driven applications)
• Output Type: Push-Pull (required for specific load driving capability)
• RoHS Compliance: ROHS3 (required for regulatory compliance)

Secondary Compatibility Criteria:

• Clock Frequency: 400 kHz or higher (backward compatible)
• Voltage Supply Range: Must encompass or exceed 2.3V ~ 5.5V
• Operating Temperature: Must support -40°C ~ 85°C minimum
• Current Output: Must support 10mA and 25mA minimum

Substitute parts are grouped into two categories:

Category A - Direct Equivalents (Full Parameter Match): Parts meeting all primary and secondary criteria with identical or superior electrical specifications.

Category B - Functional Alternatives (Reduced Specifications): Parts meeting core I/O and interface requirements but with reduced clock frequency (100 kHz) or alternative output types (Open Drain). These require application-level verification for compatibility.

Parameter Comparison

Engineering Selection Recommendations

Tier 1 - Recommended Direct Substitutes (Active Product Status):

TCA9534ADWR and PCA9534D,118 are the primary recommended substitutes. Both maintain 400 kHz clock frequency, 8-bit I/O configuration, Push-Pull output type, and 16-SOIC packaging. TCA9534ADWR offers extended lower voltage operation (1.65V minimum) compared to the original part. PCA9534D,118 maintains identical electrical specifications and SMBus compatibility. Both parts carry Active product status with established supply chains.

Tier 2 - Secondary Substitutes (Reduced Clock Frequency):

PCF8574T/3,512, PCF8574T/3,518, and PCF8574AT/3,518 operate at 100 kHz clock frequency instead of 400 kHz. These parts maintain Push-Pull output type, 8-bit I/O, interrupt capability, and 16-SOIC packaging. Applications tolerant of reduced I2C bus speed can utilize these alternatives. All three variants are Active products with high inventory availability.

Tier 3 - Limited Compatibility Alternatives:

MAX7329AWE+ and MAX7329AWE+T feature Open Drain output type instead of Push-Pull, operating at 100 kHz. These parts require external pull-up resistors and are suitable only for applications where Open Drain topology is acceptable. MAX7328AWE+ lacks interrupt output capability and is not recommended for interrupt-driven designs.

All substitute parts listed maintain ROHS3 compliance and EAR99 export classification consistent with the original part.

Frequently Asked Questions (FAQ)

Q: Can TCA9534ADWR directly replace PCA9534ADWR in existing designs?

A: TCA9534ADWR is compatible for direct substitution in most applications. Both parts operate at 400 kHz I2C frequency, provide 8-bit I/O with Push-Pull outputs, and use identical 16-SOIC packaging. The primary difference is TCA9534ADWR supports lower minimum voltage (1.65V vs. 2.3V). Verify your application does not require SMBus-specific features, as TCA9534ADWR supports I2C protocol only.

Q: Why do PCF8574 variants operate at 100 kHz instead of 400 kHz?

A: PCF8574 series devices are designed for lower-speed I2C applications. The 100 kHz clock frequency is a fundamental design characteristic of this product line. Applications requiring 400 kHz operation should prioritize TCA9534ADWR or PCA9534D,118 substitutes.

Q: What is the difference between Push-Pull and Open Drain output types?

A: Push-Pull outputs actively drive both high and low logic states. Open Drain outputs can only pull low; high state requires external pull-up resistors. PCA9534ADWR uses Push-Pull; MAX7329 variants use Open Drain. Designs using MAX7329 substitutes must include appropriate pull-up resistor networks.

Q: Are MAX7328AWE+ and MAX7329AWE+ interchangeable?

A: No. MAX7328AWE+ lacks interrupt output capability, while MAX7329AWE+ includes interrupt functionality. For applications requiring interrupt-driven operation, MAX7329AWE+ is the correct choice.

Q: What packaging options are available for substitute parts?

A: All listed substitute parts use 16-SOIC (0.295", 7.50mm width) surface mount packaging, maintaining PCB-level compatibility with PCA9534ADWR. Packaging variants (Tube, Cut Tape, Tape & Reel) affect supply chain logistics but not electrical or mechanical compatibility.

Q: Is the lower voltage range of TCA9534ADWR (1.65V minimum) a limitation?

A: No. The extended lower voltage range of TCA9534ADWR (1.65V ~ 5.5V) is a superset of PCA9534ADWR specifications (2.3V ~ 5.5V). Applications operating at 2.3V or higher are fully compatible with both parts.

Q: Can I use PCF8574 variants in high-speed I2C applications?

A: PCF8574 variants are rated for 100 kHz maximum clock frequency. Applications requiring 400 kHz I2C bus speed must use TCA9534ADWR or PCA9534D,118 substitutes. Operating PCF8574 beyond rated frequency may result in communication errors.