AP1084D33L-U Equivalent & Substitute Parts

Part Overview

The AP1084D33L-U is a linear voltage regulator IC manufactured by Diodes Incorporated, designed to deliver a fixed 3.3V output at 5A maximum current in a TO-252-3 (DPAK) surface mount package. This device is classified as obsolete, making equivalent substitute parts necessary for new designs and production continuity. The regulator incorporates over-current and over-temperature protection features suitable for general-purpose power management applications requiring stable 3.3V rails.

Substiute Parts

AP1084D33L-U

Diodes IncorporatedIn Stock: 922AP1084D33L-U Datasheet

Current PartRFQ

LD1117ADT33TR

STMicroelectronicsIn Stock: 22860LD1117ADT33TR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AP1084D33L-U is determined by the following critical electrical and mechanical parameters:

• Output Voltage: Must be fixed at 3.3V
• Package Type: Must be TO-252-3 (DPAK) for mechanical and thermal compatibility
• Output Current Capability: Minimum 1A required; 5A preferred for full functional equivalence
• Input Voltage Range: Must accommodate up to 12V input
• Protection Features: Over-current and over-temperature protection required
• Operating Temperature Range: Must support 0°C ~ 125°C
• Mounting Type: Surface mount only
• Compliance: ROHS3 compliant and REACH unaffected

The LD1117ADT33TR from STMicroelectronics meets the core substitution criteria with identical package, output voltage, and protection features. However, its output current rating of 1A is lower than the original 5A specification, making it suitable only for applications with reduced current requirements.

Parameter Comparison

Engineering Selection Recommendations

The LD1117ADT33TR is an active, production-available substitute for the obsolete AP1084D33L-U. Both devices share identical output voltage specification (3.3V), package form factor (TO-252-3 DPAK), and protection architecture (over-current and over-temperature). Both maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory continuity.

The primary design consideration is output current capacity. The LD1117ADT33TR is rated for 1A maximum output current, compared to the original 5A specification. This substitution is valid only for applications where the load current does not exceed 1A. For applications requiring the full 5A output capability of the AP1084D33L-U, alternative regulators with higher current ratings and identical package specifications must be evaluated.

The LD1117ADT33TR offers improved maximum input voltage tolerance (15V versus 12V) and documented PSRR performance (75dB at 120Hz), providing additional design margin in certain applications.

Frequently Asked Questions (FAQ)

Q: Can the LD1117ADT33TR directly replace the AP1084D33L-U in all applications?

A: Direct replacement is valid only if the application load current does not exceed 1A. The LD1117ADT33TR is rated for 1A maximum output current, while the AP1084D33L-U is rated for 5A. Pin-to-pin compatibility and package form factor are identical, but current capacity must be verified against circuit requirements.

Q: Are the TO-252-3 packages physically identical between these parts?

A: Yes. Both the AP1084D33L-U and LD1117ADT33TR use the TO-252-3 (DPAK) package with 2 leads plus tab configuration. PCB footprints and thermal characteristics are compatible.

Q: What is the significance of the higher input voltage rating on the LD1117ADT33TR?

A: The LD1117ADT33TR accepts input voltages up to 15V, compared to 12V maximum for the AP1084D33L-U. This provides additional design margin if input voltage sources exceed 12V, though both devices operate correctly within the 12V specification.

Q: Do both parts require identical external component configurations?

A: Both regulators are fixed-output devices with identical output voltage (3.3V) and protection features. External capacitor and filtering requirements should be verified against the specific datasheet for each manufacturer, as component recommendations may vary slightly.

Q: Is the LD1117ADT33TR suitable for high-frequency switching applications?

A: No. Both the AP1084D33L-U and LD1117ADT33TR are linear regulators, not switching regulators. They are suitable for low-noise, low-frequency applications but are not appropriate for high-frequency switching power supplies.

Q: What is the inventory status difference between these parts?

A: The AP1084D33L-U is obsolete with 895 pieces in stock. The LD1117ADT33TR is an active product with 22,776 pieces in stock, ensuring long-term availability for production and design continuity.