IRU1117-25CS Equivalent & Substitute Parts

Part Overview

The IRU1117-25CS is a linear voltage regulator IC from Infineon Technologies designed for positive fixed output applications. This 8-SOIC surface mount device delivers 800mA output current at a fixed 2.5V output with a maximum dropout voltage of 1.3V at 1A. The part is classified as obsolete, making identification of compatible substitute components essential for ongoing design support and production continuity.

Substiute Parts

IRU1117-25CS

Infineon TechnologiesIn Stock: 902IRU1117-25CS Datasheet

Current PartRFQ

LD1117D33CTR

STMicroelectronicsIn Stock: 7319LD1117D33CTR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRU1117-25CS is determined by the following critical parameters:

• Package Compatibility: Both main and substitute parts must use 8-SOIC (0.154", 3.90mm Width) surface mount packaging to ensure PCB layout compatibility without redesign.
• Output Configuration & Type: Positive fixed output configuration is mandatory for direct replacement.
• Current Rating: Minimum 800mA output current capability required.
• Voltage Dropout: Maximum 1.3V dropout at rated current to maintain regulation performance.
• Protection Features: Over current and over temperature protection must be present.
• Pinout Compatibility: 8-pin SOIC package ensures functional pin correspondence.

The LD1117D33CTR from STMicroelectronics meets these substitution criteria while offering enhanced specifications and active product status.

Parameter Comparison

Engineering Selection Recommendations

The LD1117D33CTR is a direct functional substitute for the IRU1117-25CS based on matching package geometry, output current capability, dropout voltage specification, and protection features. The substitute part offers the following advantages:

• Active Product Status: The LD1117D33CTR maintains active production status, ensuring long-term availability and supply chain stability compared to the obsolete IRU1117-25CS.
• Regulatory Compliance: ROHS3 compliance of the substitute part aligns with current environmental and regulatory requirements, whereas the main part is RoHS non-compliant.
• Extended Operating Range: The substitute supports -40°C to 125°C operating temperature versus 0°C to 125°C for the main part, providing broader thermal performance envelope.
• Improved Input Voltage Rating: 15V maximum input voltage on the substitute versus 7V on the main part allows operation in higher voltage supply environments.
• Enhanced PSRR: 75dB at 120Hz on the substitute versus 70dB on the main part provides superior power supply rejection.

Note: The output voltage differs (3.3V for substitute versus 2.5V for main part). Substitution is valid only when the application circuit can accommodate the 3.3V output specification or when the substitute is used in an adjustable configuration.

Frequently Asked Questions (FAQ)

Q: Can the LD1117D33CTR directly replace the IRU1117-25CS without PCB modifications?

A: Yes, from a package and pinout perspective. Both devices use 8-SOIC (0.154", 3.90mm Width) surface mount packaging with identical pin configurations. However, the output voltage differs (3.3V versus 2.5V), so circuit validation is required to confirm the application tolerates the higher output voltage.

Q: What are the critical parameters that determine substitution eligibility?

A: Package type (8-SOIC), output current rating (800mA minimum), voltage dropout specification (1.3V maximum), output configuration (positive fixed), and protection features (over current and over temperature) are the primary criteria. All must match or exceed the original part specifications.

Q: Why is the LD1117D33CTR recommended over other potential substitutes?

A: The LD1117D33CTR matches all mandatory substitution parameters while offering active product status, regulatory compliance (ROHS3), extended operating temperature range, and improved electrical performance characteristics compared to the obsolete IRU1117-25CS.

Q: Are there any compatibility concerns with the 8-SOIC package?

A: No. Both parts use identical 8-SOIC (0.154", 3.90mm Width) packaging, ensuring mechanical and electrical compatibility at the PCB level without layout modifications.

Q: What should be verified before implementing the LD1117D33CTR as a substitute?

A: Confirm that the application circuit design can operate with the 3.3V fixed output voltage. Verify input voltage supply does not exceed 15V. Validate thermal performance under maximum load conditions (800mA output current). Confirm protection feature requirements (over current and over temperature) are met by the substitute device.