PCF8575CDBQR I/O Expander Equivalent & Substitute Parts

Part Overview

The PCF8575CDBQR is a 16-bit I/O expander with I2C and SMBus interface operating at 400 kHz, manufactured by Texas Instruments in a 24-SSOP package. This part is currently obsolete, which necessitates identification of functionally equivalent alternatives for new designs or production continuity. Substitute parts must maintain compatibility with the core I2C/SMBus protocol, I/O count, and operating frequency while accommodating differences in voltage supply ranges, output configurations, and package specifications.

Substiute Parts

PCF8575CDBQR

Texas InstrumentsIn Stock: 10416PCF8575CDBQR Datasheet

Current PartRFQ

PCF8575DBR

Texas InstrumentsIn Stock: 16933PCF8575DBR Datasheet

MFR RecommendedRFQ

MAX7313AEG+

Analog Devices Inc./Maxim IntegratedIn Stock: 2060MAX7313AEG+ Datasheet

MFR RecommendedRFQ

MAX7313AEG+T

Analog Devices Inc./Maxim IntegratedIn Stock: 8167MAX7313AEG+T Datasheet

MFR RecommendedRFQ

NCT5655Y

Nuvoton Technology CorporationIn Stock: 925NCT5655Y Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following core parameters: 16 I/O count, I2C/SMBus 400 kHz interface, surface mount technology, and ROHS3 compliance. The PCF8575CDBQR operates within a 4.5V to 5.5V supply window with open drain output configuration. Substitute parts must support the same I/O architecture and communication protocol. Variations in voltage supply range, output type (open drain vs. push-pull), current ratings, temperature range, and package dimensions are permissible provided the part functions within the specified I2C/SMBus protocol and maintains 16 I/O capability. The following parts meet these criteria:

• PCF8575DBR: Texas Instruments active part with identical base product number, expanded voltage range (2.5V ~ 5.5V), push-pull output, and improved MSL rating.
• MAX7313AEG+ and MAX7313AEG+T: Analog Devices/Maxim Integrated alternatives with open drain output, extended temperature range (-40°C ~ 125°C), lower voltage supply (2V ~ 3.6V), and PWM features.
• NCT5655Y: Nuvoton Technology alternative with open drain output, wide voltage range (2.3V ~ 5.5V), and QFN package option.

Parameter Comparison

Engineering Selection Recommendations

PCF8575DBR is the primary substitute for direct replacement within Texas Instruments product line continuity. It maintains active product status, identical I/O and interface specifications, and ROHS3 compliance. The expanded voltage supply range (2.5V ~ 5.5V) provides greater design flexibility. The push-pull output configuration differs from the original open drain design and must be evaluated for circuit compatibility. Package dimension variation (0.209" vs. 0.154" width) requires PCB layout verification.

MAX7313AEG+T and MAX7313AEG+ offer extended operating temperature range (-40°C ~ 125°C) and higher output current capability (50mA), beneficial for applications requiring enhanced thermal performance or higher drive capability. Open drain output maintains compatibility with the original design topology. The lower voltage supply range (2V ~ 3.6V) restricts use to low-voltage systems. Both parts are active and ROHS3 compliant.

NCT5655Y provides the widest voltage supply compatibility (2.3V ~ 5.5V) and maintains open drain output configuration. The QFN package format differs from SSOP and requires distinct PCB footprint design. Active product status and ROHS3 compliance support long-term availability.

Frequently Asked Questions (FAQ)

Q: Can PCF8575DBR replace PCF8575CDBQR in existing designs without modification?

A: PCF8575DBR maintains identical I/O count, interface protocol, and clock frequency. However, the output type differs (push-pull vs. open drain), requiring circuit analysis to confirm compatibility. Package width variation (0.209" vs. 0.154") necessitates PCB layout review.

Q: What is the primary advantage of MAX7313AEG+T over PCF8575CDBQR?

A: MAX7313AEG+T extends operating temperature range to 125°C and provides 50mA output current versus 25mA maximum on the original part. These specifications support applications with higher thermal or current demands. The lower voltage supply range (2V ~ 3.6V) limits use to low-voltage systems.

Q: Is NCT5655Y suitable for 5V applications?

A: Yes. NCT5655Y operates within 2.3V ~ 5.5V supply range, supporting 5V system integration. The QFN package requires distinct PCB footprint design compared to SSOP alternatives.

Q: Do all substitute parts maintain I2C/SMBus 400 kHz compatibility?

A: Yes. All listed substitutes operate at 400 kHz clock frequency and support I2C and SMBus protocols, ensuring protocol-level compatibility with the original PCF8575CDBQR.

Q: What packaging options are available among substitutes?

A: PCF8575DBR and MAX7313AEG+T are supplied in Cut Tape (CT) & Digi-Reel® format. MAX7313AEG+ is supplied in Tube. NCT5655Y is supplied in Tray. Package selection depends on production volume and assembly requirements.