UC2855ADW Equivalent & Substitute Parts

Part Overview

The UC2855ADW is a Power Factor Correction (PFC) controller IC manufactured by Texas Instruments, designed for average current mode operation at 500kHz switching frequency. This device is classified as Last Time Buy, indicating end-of-life status. The UC2855ADW operates in the 15.5V to 20V supply voltage range and is packaged in a 20-SOIC surface mount configuration with RoHS3 compliance.

Due to its Last Time Buy status, identifying functionally compatible substitute parts is essential for design continuity and long-term supply chain planning. The UCC28180DR represents the manufacturer-recommended alternative for applications requiring PFC control functionality.

Substiute Parts

UC2855ADW

Texas InstrumentsIn Stock: 2127UC2855ADW Datasheet

Current PartRFQ

UCC28180DR

Texas InstrumentsIn Stock: 25251UCC28180DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the UC2855ADW with the UCC28180DR is based on the following criteria:

Functional Category Match: Both devices are Power Factor Correction (PFC) controller ICs from Texas Instruments, designed for power supply applications requiring power factor correction functionality.

Control Mode Consideration: The UC2855ADW operates in Average Current mode at 500kHz, while the UCC28180DR operates in Continuous Conduction (CCM) mode with a switching frequency range of 18kHz to 250kHz. These represent different control topologies and frequency ranges, requiring circuit design evaluation.

Supply Voltage Compatibility: The UC2855ADW requires 15.5V to 20V supply voltage, while the UCC28180DR operates at 21V. The voltage specifications differ and must be verified against application requirements.

Package Difference: The UC2855ADW uses a 20-SOIC package, while the UCC28180DR uses an 8-SOIC package. This represents a significant physical and pin-count difference requiring PCB redesign.

Compliance and Certifications: Both parts maintain RoHS3 compliance and EAR99 ECCN classification, ensuring regulatory consistency.

Parameter Comparison

Engineering Selection Recommendations

The UCC28180DR is designated as the manufacturer-recommended substitute for the UC2855ADW. However, substitution requires careful evaluation of application-specific requirements due to the following factors:

Product Status: The UC2855ADW is Last Time Buy, while the UCC28180DR is Active. This ensures long-term availability and supply continuity with the substitute part.

Regulatory Compliance: Both parts maintain ROHS3 compliance and identical ECCN/HTSUS classifications, ensuring no regulatory barriers to substitution.

Moisture Sensitivity: The UCC28180DR offers superior moisture handling characteristics (MSL 1, Unlimited) compared to the UC2855ADW (MSL 2, 1 Year), providing advantages for storage and handling.

Operating Temperature Range: The UCC28180DR supports -40°C to 125°C, exceeding the UC2855ADW range of -40°C to 85°C, offering broader thermal operating capability.

Substitution requires verification of control mode compatibility (Average Current versus CCM), switching frequency alignment, supply voltage requirements, and PCB layout modifications due to package differences.

Frequently Asked Questions (FAQ)

Q: Can the UCC28180DR directly replace the UC2855ADW without circuit modifications?

A: No. The UCC28180DR differs in control mode (CCM versus Average Current), switching frequency range (18kHz-250kHz versus 500kHz fixed), package type (8-SOIC versus 20-SOIC), and pin configuration. Circuit redesign is required.

Q: What are the key differences in control topology between these parts?

A: The UC2855ADW uses Average Current mode control, while the UCC28180DR uses Continuous Conduction (CCM) mode. These represent different feedback and regulation approaches requiring distinct circuit implementations.

Q: Are there supply voltage compatibility issues?

A: Yes. The UC2855ADW operates at 15.5V to 20V, while the UCC28180DR operates at 21V. Application supply voltage must be verified against both specifications.

Q: What PCB modifications are necessary due to package differences?

A: The UC2855ADW uses a 20-SOIC package (0.295" width), while the UCC28180DR uses an 8-SOIC package (0.154" width). Pin count and layout differ significantly, requiring complete PCB redesign.

Q: Do both parts meet the same regulatory standards?

A: Yes. Both parts are ROHS3 compliant with identical ECCN (EAR99) and HTSUS (8542.39.0001) classifications.

Q: Which part offers better long-term availability?

A: The UCC28180DR is Active status, ensuring ongoing manufacturing and supply availability, while the UC2855ADW is Last Time Buy with limited future availability.