AP1506-33T5L-U Equivalent & Substitute Parts

Part Overview

The AP1506-33T5L-U is a buck switching regulator IC manufactured by Diodes Incorporated, designed to deliver a fixed 3.3V output at 3A from input voltages ranging from 4.5V to 22V. This TO-220-5 package component operates at 150kHz switching frequency and is compliant with ROHS3 standards.

The AP1506-33T5L-U has been discontinued at DiGi Electronics. Identifying equivalent substitute parts ensures design continuity and maintains supply chain reliability for applications requiring 3.3V buck regulation with 3A output capability.

Substiute Parts

AP1506-33T5L-U

Diodes IncorporatedIn Stock: 1062AP1506-33T5L-U Datasheet

Current PartRFQ

MIC4575-3.3WT

Microchip TechnologyIn Stock: 4220MIC4575-3.3WT Datasheet

MFR RecommendedRFQ

MIC4576-3.3WT

Microchip TechnologyIn Stock: 3727MIC4576-3.3WT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the AP1506-33T5L-U are selected based on the following critical parameters that determine functional equivalence:

• Output voltage: 3.3V fixed
• Output current capability: minimum 3A
• Package type: TO-220-5 (identical pinout and thermal characteristics)
• Input voltage range: compatible with 4.5V to 22V operation
• Topology: buck or buck-boost (buck-boost topology is backward compatible with buck applications)
• Mounting type: through-hole
• Compliance: ROHS3 compliant

The substitute parts identified maintain these core electrical and mechanical specifications, ensuring direct replacement capability in existing designs.

Parameter Comparison

Engineering Selection Recommendations

MIC4576-3.3WT is the primary substitute for AP1506-33T5L-U. Both devices deliver 3A output current at 3.3V with identical TO-220-5 packaging. The MIC4576-3.3WT maintains ROHS3 compliance and extends input voltage tolerance to 36V, providing enhanced design margin. The part is currently active in production with unlimited moisture sensitivity rating, improving supply reliability and handling flexibility.

MIC4575-3.3WT is a secondary substitute option. While it shares the same 3.3V output voltage, TO-220-5 package, and ROHS3 compliance, its 1.7A output current rating falls below the 3A requirement of the original design. This part is suitable only for applications where output current demand does not exceed 1.7A. The MIC4575-3.3WT offers dual-mode buck-boost topology, which provides operational flexibility beyond the original buck-only function.

Both Microchip substitutes are active products with superior moisture sensitivity ratings (MSL 1) compared to the discontinued Diodes part (MSL 3), reducing handling and storage constraints.

Frequently Asked Questions (FAQ)

Q: Can MIC4576-3.3WT directly replace AP1506-33T5L-U without PCB modifications?

A: Yes. Both devices use identical TO-220-5 packaging with the same pinout and thermal characteristics. No PCB layout changes are required for direct substitution.

Q: Why is MIC4575-3.3WT listed as a substitute if its output current is only 1.7A?

A: MIC4575-3.3WT is listed as a substitute for applications where the design does not require the full 3A output current capability. It remains functionally equivalent for lower-current 3.3V buck regulation circuits. For designs requiring 3A output, MIC4576-3.3WT is the appropriate choice.

Q: What is the impact of the higher switching frequency in the Microchip parts (200kHz vs. 150kHz)?

A: Higher switching frequency allows for smaller external filter components while maintaining equivalent output ripple and transient response. This may reduce PCB area and component cost in new designs, though existing designs using 150kHz-optimized components will function correctly with the 200kHz parts.

Q: Are the Microchip substitutes compatible with existing circuit designs optimized for the AP1506-33T5L-U?

A: Yes. The substitutes maintain the same output voltage, package type, and basic buck regulation topology. Existing feedback networks, input/output filtering, and thermal management designs remain valid. The extended input voltage range and improved moisture sensitivity of the Microchip parts provide additional design margin.

Q: What is the significance of the MSL rating difference between the original and substitute parts?

A: The AP1506-33T5L-U has MSL 3 (168 hours), requiring moisture baking before reflow soldering if exposed to humid conditions. The Microchip substitutes have MSL 1 (unlimited), eliminating moisture sensitivity concerns and simplifying manufacturing logistics.