AP1117T18L-U Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The AP1117T18L-U is a linear voltage regulator IC manufactured by Diodes Incorporated, designed to provide a fixed 1.8V output at 1A current capacity in a TO-220-3 through-hole package. This device is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing design support and production continuity. The part delivers positive fixed output regulation with integrated over-current and over-temperature protection features suitable for power management applications requiring stable low-voltage rails.

Substiute Parts

AP1117T18L-U

Diodes IncorporatedIn Stock: 2156AP1117T18L-U Datasheet

Current PartRFQ

LD1117V18

STMicroelectronicsIn Stock: 3554LD1117V18 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AP1117T18L-U is determined by the following critical electrical and mechanical parameters:

Fixed Output Voltage: 1.8V output is the primary functional requirement. Substitute parts must deliver identical fixed output voltage.

Output Current Capacity: The AP1117T18L-U provides 1A maximum output current. Substitute parts must meet or exceed this current specification to maintain design compatibility.

Package Configuration: TO-220-3 through-hole mounting is required for mechanical and thermal compatibility. Substitute parts must use identical or pin-compatible package types.

Input Voltage Range: Maximum input voltage of 18V establishes the upper operating boundary. Substitute parts must support this input voltage specification.

Voltage Dropout Characteristics: Maximum dropout voltage of 1.4V @ 1A defines the minimum input-to-output differential required for proper regulation. Substitute parts must maintain acceptable dropout performance.

Protection Features: Over-current and over-temperature protection are mandatory safety functions. Substitute parts must include both protection mechanisms.

Compliance & Status: RoHS3 compliance and product status are critical for regulatory and supply chain considerations.

The LD1117V18 manufactured by STMicroelectronics meets these substitution criteria with compatible electrical specifications and identical package type.

Parameter Comparison

Engineering Selection Recommendations

The LD1117V18 is a direct functional substitute for the AP1117T18L-U based on matching output voltage, package type, protection features, and compliance certifications. Both devices are obsolete products, indicating limited future availability through standard distribution channels.

Key Compatibility Factors:

The LD1117V18 delivers the same 1.8V fixed output voltage and maintains identical TO-220-3 package configuration, ensuring mechanical and thermal compatibility in existing PCB designs without layout modifications.

Both parts provide over-current and over-temperature protection with matching quiescent current specifications and identical operating temperature ranges, supporting equivalent functional performance in power management applications.

Design Considerations:

The LD1117V18 specifies 800mA maximum output current compared to the AP1117T18L-U's 1A rating. Applications requiring full 1A output current must verify that the 800mA specification meets system requirements.

The LD1117V18 supports maximum input voltage of 15V versus 18V for the AP1117T18L-U. Designs operating at input voltages between 15V and 18V require verification that the lower maximum input rating is acceptable.

Both devices maintain RoHS3 compliance and identical operating temperature specifications, supporting regulatory and environmental requirements.

Frequently Asked Questions (FAQ)

Q: Can the LD1117V18 replace the AP1117T18L-U in existing designs?

A: The LD1117V18 is compatible for applications where output current requirements do not exceed 800mA and input voltage remains below 15V. Both devices provide identical 1.8V fixed output voltage, matching protection features, and identical TO-220-3 package configuration. Verify that your application's current and input voltage specifications fall within the LD1117V18's operating range.

Q: What are the key differences between these two parts?

A: The primary differences are output current capacity (AP1117T18L-U: 1A vs. LD1117V18: 800mA) and maximum input voltage (AP1117T18L-U: 18V vs. LD1117V18: 15V). The LD1117V18 offers superior PSRR performance at 75dB compared to 60dB for the AP1117T18L-U. Both parts maintain identical output voltage, protection features, and package type.

Q: Are both parts still available for purchase?

A: Both the AP1117T18L-U and LD1117V18 are classified as obsolete products. Availability through standard distribution channels is limited. Verify current inventory status with authorized component suppliers before finalizing procurement decisions.

Q: Do these parts require identical PCB footprints?

A: Yes. Both devices use the TO-220-3 through-hole package with identical pin configuration and mechanical dimensions. No PCB layout modifications are required for substitution.

Q: What compliance certifications apply to both parts?

A: Both the AP1117T18L-U and LD1117V18 are RoHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic component manufacturing and distribution.

Q: How do the protection features compare?

A: Both devices provide identical over-current and over-temperature protection mechanisms. Protection performance is equivalent across both parts.