AP1117D25L-U Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The AP1117D25L-U is a linear voltage regulator IC manufactured by Diodes Incorporated, designed to provide a fixed 2.5V output at 1A maximum current in a TO-252-3 (DPAK) surface mount package. This positive fixed output regulator includes over-current and over-temperature protection features, operating across a 0°C to 125°C temperature range with a maximum input voltage of 18V and dropout voltage of 1.4V at 1A.

The AP1117D25L-U is classified as obsolete. Equivalent and substitute parts are necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications utilizing this regulator topology.

Substiute Parts

AP1117D25L-U

Diodes IncorporatedIn Stock: 1038AP1117D25L-U Datasheet

Current PartRFQ

IRU1117-25CD

Infineon TechnologiesIn Stock: 974IRU1117-25CD Datasheet

MFR RecommendedRFQ

LD1117DT25CTR

STMicroelectronicsIn Stock: 2820LD1117DT25CTR Datasheet

MFR RecommendedRFQ

LD1117DT25TR

STMicroelectronicsIn Stock: 7361LD1117DT25TR Datasheet

MFR RecommendedRFQ

LM1117DT-2.5/NOPB

National SemiconductorIn Stock: 1369LM1117DT-2.5/NOPB Datasheet

MFR RecommendedRFQ

LM1117DTX-2.5/NOPB

Texas InstrumentsIn Stock: 1569LM1117DTX-2.5/NOPB Datasheet

MFR RecommendedRFQ

NCP1117DT25G

onsemiIn Stock: 10382NCP1117DT25G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AP1117D25L-U is determined by the following critical parameters:

Fixed Output Voltage: 2.5V output is the primary selection criterion. All substitute parts must provide identical 2.5V fixed output.

Package Compatibility: All substitute parts must use TO-252-3 (DPAK) surface mount packaging to ensure PCB layout and thermal management compatibility.

Output Current Rating: The AP1117D25L-U provides 1A maximum output current. Substitute parts rated at 800mA or higher satisfy this requirement, as they can deliver the required current within the design envelope.

Input Voltage Range: Maximum input voltage of 18V for the AP1117D25L-U establishes the upper limit. Substitute parts with maximum input voltage ratings of 15V or higher are compatible with standard linear regulator input conditions.

Protection Features: Over-current and over-temperature protection are present in all substitute candidates, meeting the safety and reliability requirements of the original design.

Dropout Voltage: The AP1117D25L-U specifies 1.4V dropout at 1A. Substitute parts with dropout voltages of 1.2V to 1.3V at their rated output current provide equivalent or superior performance.

Temperature Range: Operating temperature range of 0°C to 125°C is maintained across all substitute parts, with some offering extended lower temperature operation to -40°C.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Active Product Status):

LD1117DT25TR and LD1117DT25CTR from STMicroelectronics are the preferred substitutes. Both are active products with ROHS3 compliance, identical 2.5V fixed output, TO-252-3 DPAK packaging, and 800mA output current capability. LD1117DT25TR offers superior PSRR performance (75dB) and lower dropout voltage (1.2V @ 800mA). LD1117DT25CTR provides extended operating temperature range (-40°C to 125°C), beneficial for industrial applications.

LM1117DTX-2.5/NOPB from Texas Instruments is an active product substitute with ROHS3 compliance, 2.5V fixed output, and 800mA current rating. It features lower quiescent current (5mA) compared to the original 10mA specification, reducing standby power consumption. PSRR performance matches STMicroelectronics alternatives at 75dB.

LM1117DT-2.5/NOPB from National Semiconductor is an active product with equivalent electrical characteristics to the Texas Instruments variant, including 5mA quiescent current and 75dB PSRR.

Secondary Substitutes (Obsolete Product Status):

NCP1117DT25G from onsemi maintains 1A output current matching the original AP1117D25L-U specification, with ROHS3 compliance and active product status in some markets. Maximum input voltage of 20V exceeds the original 18V rating.

IRU1117-25CD from Infineon is obsolete and exhibits reduced maximum input voltage (7V), limiting its application scope compared to the original design.

Compliance Considerations:

All recommended active substitutes maintain ROHS3 compliance. The AP1117D25L-U is ROHS3 compliant; IRU1117-25CD is non-compliant and should be avoided in applications requiring regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can I substitute an 800mA-rated regulator for the 1A AP1117D25L-U?

A: Yes, if your application draws less than 800mA at the 2.5V output. The LD1117DT25TR, LD1117DT25CTR, LM1117DT-2.5/NOPB, and LM1117DTX-2.5/NOPB all provide 800mA capability. If your design requires the full 1A output, use NCP1117DT25G, which maintains the 1A rating.

Q: What is the impact of different dropout voltages?

A: Dropout voltage determines the minimum input voltage required to maintain regulation at full output current. The AP1117D25L-U specifies 1.4V dropout at 1A. Substitute parts with 1.2V to 1.3V dropout at their rated current provide equivalent or superior performance, requiring lower input voltages for stable operation.

Q: Are all substitutes pin-compatible?

A: Yes. All substitute parts use TO-252-3 (DPAK) packaging with identical pin configuration: input, ground, and output. Direct PCB replacement is possible without layout modification.

Q: Why do some substitutes have lower quiescent current?

A: LM1117DT-2.5/NOPB and LM1117DTX-2.5/NOPB specify 5mA quiescent current versus 10mA for the original. Lower quiescent current reduces standby power consumption in battery-powered or low-power applications without affecting regulation performance.

Q: What is the difference between LD1117DT25TR and LD1117DT25CTR?

A: Both are STMicroelectronics LD1117 variants with identical electrical performance. LD1117DT25CTR supports extended operating temperature range (-40°C to 125°C) versus LD1117DT25TR (0°C to 125°C). LD1117DT25CTR is supplied in Cut Tape & Digi-Reel packaging; LD1117DT25TR is supplied in Tape & Reel format.

Q: Should I use NCP1117DT25G to maintain 1A output capability?

A: NCP1117DT25G preserves the 1A output rating and is ROHS3 compliant. However, it is classified as obsolete. For new designs requiring 1A output with active product status, availability may be limited. Verify supply chain continuity before committing to this part.

Q: Is IRU1117-25CD suitable as a substitute?

A: IRU1117-25CD is not recommended. It is obsolete, non-ROHS3 compliant, and exhibits reduced maximum input voltage (7V) compared to the original 18V specification, limiting application flexibility.

Q: What PSRR performance difference should I expect?

A: The AP1117D25L-U provides 60dB PSRR at 180Hz. Most active substitutes offer 75dB PSRR at 120Hz, representing improved power supply rejection. NCP1117DT25G provides 68dB PSRR. Higher PSRR values reduce output voltage ripple from input supply noise.