PCF8575DB Equivalent & Substitute Parts

Part Overview

The PCF8575DB is a 16-bit I/O Expander with I2C and SMBus interface operating at 400 kHz, manufactured by Texas Instruments in a 24-SSOP surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. The PCF8575DB provides push-pull output capability with interrupt output functionality and power-on reset features, suitable for applications requiring expanded I/O capabilities in embedded systems and industrial control applications.

Substiute Parts

PCF8575DB

Texas InstrumentsIn Stock: 1432PCF8575DB Datasheet

Current PartRFQ

PCF8575DBR

Texas InstrumentsIn Stock: 16933PCF8575DBR Datasheet

MFR RecommendedRFQ

MAX7326AEG+T

Analog Devices Inc./Maxim IntegratedIn Stock: 1032MAX7326AEG+T Datasheet

MFR RecommendedRFQ

MCP23016-I/ML

Microchip TechnologyIn Stock: 2045MCP23016-I/ML Datasheet

MFR RecommendedRFQ

MCP23016-I/SP

Microchip TechnologyIn Stock: 1000417MCP23016-I/SP Datasheet

MFR RecommendedRFQ

MCP23016-I/SS

Microchip TechnologyIn Stock: 1521MCP23016-I/SS Datasheet

MFR RecommendedRFQ

MCP23016T-I/ML

Microchip TechnologyIn Stock: 3798MCP23016T-I/ML Datasheet

MFR RecommendedRFQ

MCP23016T-I/SO

Microchip TechnologyIn Stock: 3494MCP23016T-I/SO Datasheet

MFR RecommendedRFQ

MCP23016T-I/SS

Microchip TechnologyIn Stock: 856MCP23016T-I/SS Datasheet

MFR RecommendedRFQ

PCF8575TS/1,112

NXP USA Inc.In Stock: 2675PCF8575TS/1,112 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the PCF8575DB is determined by the following critical parameters: 16 I/O count, I2C interface at 400 kHz clock frequency, push-pull output type, interrupt output capability, and power-on reset feature. Supply voltage range, operating temperature range, output current specifications, and package type are secondary considerations that define compatibility within application constraints.

Substitute parts are grouped into two categories:

Category 1: Direct Package Equivalents (24-SSOP) Parts maintaining the identical 24-SSOP package footprint with matching electrical specifications. These provide pin-compatible replacements suitable for direct PCB substitution.

Category 2: Functional Equivalents (Alternative Packages) Parts with identical or superior electrical specifications but different package types (28-SSOP, 28-SOIC, 28-QFN, 28-SPDIP). These require PCB redesign or adapter solutions but offer enhanced availability or performance characteristics.

Parameter Comparison

Engineering Selection Recommendations

For Direct PCB Replacement (No Layout Changes): PCF8575DBR is the primary recommended substitute. It maintains identical 24-SSOP package geometry and electrical interface compatibility with the obsolete PCF8575DB. Both parts are Texas Instruments products with ROHS3 compliance and unlimited moisture sensitivity rating. PCF8575DBR is currently in active production status with significantly higher inventory availability (16840 units).

PCF8575TS/1,112 from NXP USA Inc. provides an alternative direct package replacement with matching 24-SSOP footprint, identical supply voltage range, and equivalent output current specifications. This part is also in active production with ROHS3 compliance.

For New Designs Permitting Layout Modification: MCP23016 series from Microchip Technology offers multiple package options (28-QFN, 28-SOIC, 28-SSOP, 28-SPDIP) with enhanced output current capability (25mA) and extended operating temperature range in certain variants. These parts maintain I2C 400 kHz interface compatibility and interrupt output functionality. MCP23016-I/SP offers the highest inventory availability (1,000,399 units) in through-hole 28-SPDIP package for prototyping and legacy system applications.

MAX7326AEG+T from Analog Devices Inc./Maxim Integrated provides the widest supply voltage range (1.71V ~ 5.5V) and extended operating temperature range (-40°C ~ 125°C), suitable for applications requiring enhanced environmental performance. This part is available in 24-QSOP package with active production status.

All recommended substitutes maintain ROHS3 compliance, unlimited or extended moisture sensitivity ratings, and active product status, ensuring long-term availability and regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can PCF8575DBR be used as a direct replacement for PCF8575DB? A: Yes. PCF8575DBR maintains identical 24-SSOP package footprint, I2C/SMBus interface at 400 kHz, 16 I/O configuration, push-pull output type, interrupt output capability, and power-on reset feature. Both operate across 2.5V to 5.5V supply range and -40°C to 85°C temperature range. The primary difference is product status (active vs. obsolete) and higher inventory availability.

Q: What is the difference between MCP23016 variants (I/ML, I/SP, I/SS, T/ML, T/SO, T/SS)? A: MCP23016 variants differ in package type and packaging format. I/ML and T/ML use 28-QFN (6x6) surface mount packages. I/SP uses 28-SPDIP through-hole package. I/SS and T/SS use 28-SSOP surface mount packages. T/SO uses 28-SOIC surface mount package. The "T" designation indicates tape and reel packaging format. All variants maintain identical electrical specifications: 16 I/O, I2C 400 kHz interface, 25mA output current, 2V to 5.5V supply range, and -40°C to 85°C operating temperature.

Q: Is MAX7326AEG+T compatible with PCF8575DB applications? A: MAX7326AEG+T provides functional compatibility through identical 16 I/O count, I2C 400 kHz interface, push-pull output type, and interrupt output capability. However, it uses 24-QSOP package instead of 24-SSOP, requiring PCB redesign. MAX7326AEG+T offers superior specifications: wider supply voltage range (1.71V ~ 5.5V) and extended operating temperature range (-40°C ~ 125°C). Output current is specified at 20mA, within acceptable range for most applications.

Q: Why do some parts specify different output current values (10mA vs. 25mA)? A: Output current specifications define the maximum current the I/O expander can source or sink per output pin. PCF8575DB and PCF8575DBR specify dual values (10mA, 25mA) representing different operating conditions. MCP23016 series specifies 25mA, providing higher current capability. MAX7326AEG+T specifies 20mA. Selection depends on application load requirements. Higher current capability provides design margin for driving external loads.

Q: What is the significance of MSL (Moisture Sensitivity Level) ratings? A: MSL rating indicates moisture sensitivity during storage and handling. MSL 1 (unlimited) means the component has no moisture sensitivity restrictions and can be stored indefinitely without special precautions. MSL 3 (168 hours) requires controlled storage conditions and has a 168-hour floor life after moisture exposure. PCF8575DB, PCF8575DBR, and most substitutes carry MSL 1 rating, simplifying inventory management and reducing handling costs.

Q: Can through-hole MCP23016-I/SP replace surface mount PCF8575DB? A: MCP23016-I/SP provides functional electrical compatibility but uses 28-SPDIP through-hole package versus 24-SSOP surface mount. Direct PCB replacement is not possible without significant layout redesign. This variant is suitable for prototype development, legacy system repairs, or applications where through-hole mounting is preferred. Pin count differs (28 vs. 24), requiring careful pinout verification.