UCC3585D Equivalent & Substitute Parts

Part Overview

The UCC3585D is a buck regulator positive output step-down DC-DC controller IC manufactured by Texas Instruments in 16-SOIC packaging. This device functions as a transistor driver for step-down topology applications with a single output phase. The UCC3585D operates with a supply voltage range of 3V to 5.5V and a switching frequency of 500kHz, featuring synchronous rectification, current limit, enable, frequency control, and soft start capabilities.

The UCC3585D is classified as Last Time Buy, indicating that the manufacturer has discontinued or will discontinue production. This status necessitates identification of equivalent substitute parts to ensure design continuity and supply chain reliability for new designs or production transitions.

Substiute Parts

UCC3585D

Texas InstrumentsIn Stock: 816UCC3585D Datasheet

Current PartRFQ

TPS628503DRLR

Texas InstrumentsIn Stock: 3883TPS628503DRLR Datasheet

MFR RecommendedRFQ

LM2745MTC/NOPB

Texas InstrumentsIn Stock: 24558LM2745MTC/NOPB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the UCC3585D requires alignment across the following critical parameters:

Functional Equivalence: All substitute parts must operate as buck regulator controllers with step-down topology, positive output configuration, and single-output architecture.

Electrical Compatibility: Supply voltage range, switching frequency, duty cycle capability, and synchronous rectification support determine functional interchangeability. The UCC3585D operates at 3V to 5.5V supply with 500kHz switching frequency and 100% maximum duty cycle.

Control Feature Alignment: The presence of current limit, enable, frequency control, and soft start functions must be maintained or exceeded in substitute parts.

Package and Mounting: Surface mount technology is required. Package form factor differences (16-SOIC versus alternative packages) may require PCB layout modifications.

Compliance and Status: RoHS3 compliance and active product status are preferred to ensure long-term availability and regulatory alignment.

Two substitute parts are identified based on these criteria:

1. TPS628503DRLR - Integrated buck regulator with adjustable output, higher current capability (3A), and extended temperature range. Different package (SOT-583) and output type (adjustable vs. controller).

2. LM2745MTC/NOPB - Buck regulator controller with similar architecture, extended supply voltage range (3V to 6V), broader switching frequency range (50kHz to 1MHz), and additional control features including power good and tracking.

Parameter Comparison

Engineering Selection Recommendations

LM2745MTC/NOPB is the primary substitute for controller-based applications. This part maintains the transistor driver output type and controller architecture of the UCC3585D. It offers extended supply voltage range (3V to 6V), broader switching frequency capability (50kHz to 1MHz), and additional control features (power good, tracking). The LM2745MTC/NOPB is ROHS3 compliant with active product status, ensuring long-term availability. The 14-TSSOP package differs from the 16-SOIC, requiring PCB layout redesign. Operating temperature range extends to -40°C to 125°C (TJ), providing broader environmental coverage than the UCC3585D.

TPS628503DRLR is suitable for integrated regulator applications where external power stage control is not required. This part is an active product with extended temperature range (-40°C to 150°C TJ) and higher output current capability (3A). However, it functions as an integrated buck regulator with adjustable output rather than a controller IC, fundamentally changing the circuit architecture. The SOT-583 package is significantly smaller than 16-SOIC, enabling space-constrained designs but requiring substantial PCB modifications.

Selection between these substitutes depends on circuit topology requirements: controller-based designs should transition to LM2745MTC/NOPB; integrated regulator designs should adopt TPS628503DRLR.

Frequently Asked Questions (FAQ)

Q: Can TPS628503DRLR directly replace UCC3585D in existing designs?

A: No. TPS628503DRLR is an integrated buck regulator, not a controller. The UCC3585D is a transistor driver controller requiring external power stage components. Direct substitution requires complete circuit redesign. TPS628503DRLR is suitable only for new designs requiring integrated regulation.

Q: What are the package compatibility implications of switching to LM2745MTC/NOPB?

A: The LM2745MTC/NOPB uses 14-TSSOP packaging versus the UCC3585D's 16-SOIC. Pin count differs (14 vs. 16), and physical dimensions are different. PCB layout redesign is required, including trace routing and component placement modifications. Pinout must be verified against application schematics.

Q: Does LM2745MTC/NOPB support the same control features as UCC3585D?

A: LM2745MTC/NOPB supports current limit, enable, frequency control, and soft start, matching UCC3585D capabilities. Additionally, it provides power good output and tracking functionality, which are not present in UCC3585D. Clock synchronization is supported in LM2745MTC/NOPB but not in UCC3585D.

Q: Are both substitute parts RoHS3 compliant?

A: LM2745MTC/NOPB is ROHS3 compliant. TPS628503DRLR has RoHS status listed as "Not applicable," indicating it may not meet RoHS3 requirements. For applications requiring RoHS3 compliance, LM2745MTC/NOPB is the appropriate choice.

Q: What is the inventory status of substitute parts?

A: LM2745MTC/NOPB has 24,526 pieces in stock. TPS628503DRLR has 3,776 pieces in stock. Both parts are actively manufactured and available for procurement.

Q: Can switching frequency be adjusted in substitute parts?

A: UCC3585D operates at fixed 500kHz switching frequency. LM2745MTC/NOPB supports frequency control and operates across 50kHz to 1MHz range, allowing frequency adjustment. TPS628503DRLR operates at 1.8MHz to 4MHz with frequency control capability. Frequency adjustment capability differs between parts and must be evaluated against application requirements.