PCA8575DK,118 Equivalent & Substitute Parts

Part Overview

The PCA8575DK,118 is a 16-channel I/O Expander with I2C interface operating at 400 kHz, manufactured by NXP USA Inc. in a 24-SSOP surface mount package. This component is classified as Obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations. The part provides push-pull output configuration with interrupt output capability and power-on reset (POR) functionality, suitable for applications requiring expanded digital I/O capabilities in I2C-based systems.

Substiute Parts

PCA8575DK,118

NXP USA Inc.In Stock: 696PCA8575DK,118 Datasheet

Current PartRFQ

SX1509BIULTRT

Semtech CorporationIn Stock: 27353SX1509BIULTRT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PCA8575DK,118 is determined by the following core electrical and functional parameters:

• I/O Channel Count: 16 channels (mandatory match)
• Interface Protocol: I2C at 400 kHz (mandatory match)
• Interrupt Output Capability: Required for system compatibility
• Operating Temperature Range: -40°C ~ 85°C (mandatory match)
• Supply Voltage Compatibility: Overlap within specified ranges
• Output Configuration: Push-pull capability (primary requirement)
• RoHS and Regulatory Compliance: ROHS3 Compliant status

The SX1509BIULTRT from Semtech Corporation meets these core substitution criteria. While package geometry differs (28-QFN-UT versus 24-SSOP), the electrical functionality, I/O count, interface protocol, and operating specifications align with the original component's requirements. The substitute maintains I2C 400 kHz operation, 16-channel I/O expansion, interrupt output, and identical operating temperature range.

Parameter Comparison

Engineering Selection Recommendations

The SX1509BIULTRT is a functionally equivalent substitute for the obsolete PCA8575DK,118 based on matching core electrical specifications: identical 16-channel I/O count, I2C 400 kHz interface, interrupt output capability, and -40°C to 85°C operating temperature range. Both components maintain ROHS3 compliance and unlimited moisture sensitivity rating.

Design considerations for substitution include:

• Supply Voltage Range: The SX1509BIULTRT operates at 1.425V ~ 3.6V, which is narrower than the original 2.3V ~ 5.5V range. Verify system supply voltage falls within the substitute's operating window.
• Output Current Capability: The substitute provides reduced source/sink current (8mA, 15mA) compared to the original (100µA, 25mA). Confirm load requirements do not exceed substitute specifications.
• Package Transition: PCB layout modification is required due to package change from 24-SSOP to 28-QFN-UT (4x4). Pin assignment verification is mandatory.
• Active Product Status: The SX1509BIULTRT maintains active production status, ensuring long-term availability and supply chain stability.

Frequently Asked Questions (FAQ)

Q: Can the SX1509BIULTRT directly replace the PCA8575DK,118 without design changes?

A: Electrical functionality is equivalent, but package geometry differs. PCB layout redesign is required. Pin-to-pin compatibility must be verified against datasheets before implementation.

Q: What are the critical differences in electrical specifications?

A: Supply voltage range is narrower (1.425V ~ 3.6V vs. 2.3V ~ 5.5V), and output current capability is reduced (8mA/15mA vs. 100µA/25mA). Confirm your system operates within these parameters.

Q: Are both components RoHS compliant?

A: Yes, both PCA8575DK,118 and SX1509BIULTRT are ROHS3 compliant with unlimited moisture sensitivity rating (MSL 1).

Q: Why is the original part listed as Obsolete?

A: Obsolete status indicates NXP has discontinued production. The SX1509BIULTRT from Semtech provides equivalent functionality with active production status.

Q: Does the substitute support the same I2C protocol and clock frequency?

A: Yes, both components operate at I2C 400 kHz with identical interface protocol and interrupt output capability.

Q: What should be verified before implementing the substitute?

A: Verify supply voltage compatibility, confirm output current requirements do not exceed 8mA/15mA, and validate PCB layout accommodates the 28-QFN-UT package footprint.