PCA9535DB I/O Expander 16-Bit I2C Interface

Part Overview

The PCA9535DB 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 provides parallel I/O expansion for microcontroller-based systems requiring additional digital input/output lines with interrupt capability and power-on reset functionality.

The PCA9535DB is classified as Last Time Buy, indicating end-of-life status. Identifying equivalent and substitute parts is necessary to ensure design continuity, maintain supply chain flexibility, and support long-term product availability for applications currently utilizing this component.

Substiute Parts

PCA9535DB

Texas InstrumentsIn Stock: 976PCA9535DB Datasheet

Current PartRFQ

TCA9535DBR

Texas InstrumentsIn Stock: 2445TCA9535DBR Datasheet

MFR RecommendedRFQ

MAX7312AAG+

Analog Devices Inc./Maxim IntegratedIn Stock: 3806MAX7312AAG+ Datasheet

MFR RecommendedRFQ

PCA9555DB,118

NXP USA Inc.In Stock: 3379PCA9555DB,118 Datasheet

MFR RecommendedRFQ

PCF8575TS/1,118

NXP USA Inc.In Stock: 3277PCF8575TS/1,118 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the PCA9535DB are qualified based on the following critical parameters that determine functional and mechanical compatibility:

Core Substitution Criteria:

• 16-bit I/O configuration
• I2C interface at 400 kHz minimum clock frequency
• 24-SSOP package form factor
• Push-pull output type
• Interrupt output capability
• Power-on reset functionality
• Surface mount mounting type
• ROHS3 compliance

Substitute parts must maintain electrical compatibility within the specified voltage supply range and operating temperature window of the application. Output current capabilities (source/sink) may vary between substitutes; selection depends on specific load requirements. All qualified substitutes are available in the same 24-SSOP package, ensuring direct mechanical compatibility without PCB redesign.

Parameter Comparison

Engineering Selection Recommendations

TCA9535DBR is a direct functional equivalent manufactured by Texas Instruments with identical electrical specifications to the PCA9535DB. This substitute maintains the same voltage supply range (1.65V ~ 5.5V minimum exceeds the original 2.3V requirement), identical output current ratings, and operating temperature range. Product status is Active, ensuring long-term availability. This part is recommended as the primary substitute for direct replacement applications.

MAX7312AAG+ manufactured by Analog Devices Inc./Maxim Integrated provides enhanced output current capability (31mA, 43mA versus 10mA, 25mA) and extended operating temperature range (-40°C ~ 125°C). This substitute is suitable for applications requiring higher drive current or operation in elevated temperature environments. Product status is Active with full ROHS3 compliance.

PCA9555DB,118 manufactured by NXP USA Inc. maintains identical electrical specifications to the PCA9535DB, including voltage supply range, output current, and operating temperature. This substitute offers an alternative source from a different manufacturer. Product status is Active.

PCF8575TS/1,118 manufactured by NXP USA Inc. provides 16-bit I/O expansion with I2C interface at 400 kHz. This part operates within a slightly higher minimum voltage range (2.5V versus 2.3V) and lacks explicit SMBus designation, though I2C compatibility is maintained. Product status is Active. Selection of this substitute requires verification that SMBus-specific features are not required by the application.

All substitute parts are ROHS3 compliant with MSL rating of 1 (Unlimited) and are available in the same 24-SSOP package, ensuring mechanical and thermal compatibility without PCB modification.

Frequently Asked Questions (FAQ)

Q: Can the TCA9535DBR be used as a direct replacement for the PCA9535DB?

A: Yes. The TCA9535DBR is functionally equivalent with identical I/O count, interface protocol, clock frequency, output type, and package. The voltage supply range of TCA9535DBR (1.65V ~ 5.5V) encompasses the original specification (2.3V ~ 5.5V), ensuring compatibility across all operating conditions.

Q: What is the primary difference between the MAX7312AAG+ and the PCA9535DB?

A: The MAX7312AAG+ provides higher output current capability (31mA, 43mA versus 10mA, 25mA) and extended operating temperature range (-40°C ~ 125°C versus -40°C ~ 85°C). Applications requiring higher load drive current or operation above 85°C should consider this substitute.

Q: Is the PCF8575TS/1,118 compatible with SMBus applications?

A: The PCF8575TS/1,118 supports I2C interface at 400 kHz. SMBus compatibility is not explicitly specified for this part. Applications requiring SMBus-specific features should select TCA9535DBR, PCA9555DB,118, or MAX7312AAG+ instead.

Q: Are all substitute parts available in the same package as the PCA9535DB?

A: Yes. All qualified substitutes are available in the 24-SSOP (0.209", 5.30mm Width) package, enabling direct mechanical replacement without PCB redesign or layout modification.

Q: What is the significance of the Last Time Buy status for the PCA9535DB?

A: Last Time Buy indicates that the PCA9535DB has reached end-of-life. Texas Instruments will discontinue production after a specified date. Designs currently using this part should transition to an active substitute to ensure long-term supply chain continuity and avoid future component obsolescence.

Q: Do all substitute parts meet ROHS3 compliance?

A: Yes. All qualified substitute parts listed are ROHS3 compliant with MSL rating of 1 (Unlimited), meeting environmental and regulatory requirements equivalent to the original PCA9535DB.