IRU1117CD Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The IRU1117CD is a linear voltage regulator IC manufactured by Infineon Technologies, designed for positive adjustable output applications with 800mA current capability in a DPAK surface mount package. This device is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity. The IRU1117CD operates with an input voltage range up to 7V and provides adjustable output voltage between 2.5V and 3.6V, with integrated over-current and over-temperature protection features.

Substiute Parts

IRU1117CD

Infineon TechnologiesIn Stock: 100216IRU1117CD Datasheet

Current PartRFQ

LD1117DTTR

STMicroelectronicsIn Stock: 17054LD1117DTTR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRU1117CD is determined by electrical and mechanical compatibility across the following critical parameters:

Electrical Compatibility Criteria:

• Output configuration (positive adjustable)
• Output current capability (800mA minimum)
• Package type (DPAK / TO-252-3)
• Protection features (over-current and over-temperature)
• Mounting type (surface mount)

Functional Equivalence Parameters:

• Adjustable output voltage range that encompasses or exceeds the original specification
• Input voltage rating sufficient for the application
• Dropout voltage performance
• Quiescent current characteristics
• PSRR performance at 120Hz

The LD1117DTTR from STMicroelectronics meets these substitution criteria through identical package configuration, matching output current rating, compatible protection features, and superior electrical specifications in key performance areas.

Parameter Comparison

Engineering Selection Recommendations

The LD1117DTTR from STMicroelectronics is the qualified substitute for the obsolete IRU1117CD based on the following engineering factors:

Product Status & Availability: The IRU1117CD is classified as obsolete, while the LD1117DTTR maintains active production status with documented inventory availability. This ensures long-term supply chain continuity and technical support.

Regulatory Compliance: The LD1117DTTR is ROHS3 compliant, meeting current environmental and regulatory standards. The IRU1117CD is RoHS non-compliant, which may present procurement and compliance challenges in regulated markets.

Electrical Performance: The LD1117DTTR provides equivalent or superior performance across all measured electrical parameters. The lower quiescent current (5mA vs. 10mA) and improved PSRR (75dB vs. 70dB) represent measurable performance enhancements. The lower dropout voltage at rated current (1.2V @ 800mA vs. 1.3V @ 1A) improves efficiency in power-constrained applications.

Package & Mechanical Compatibility: Both devices utilize identical DPAK (TO-252-3) surface mount packaging with matching pin configurations, enabling direct PCB footprint compatibility without layout modifications.

Operating Temperature Consideration: The IRU1117CD operates to 150°C while the LD1117DTTR is rated to 125°C. Applications requiring operation above 125°C must retain the IRU1117CD or identify alternative solutions. For standard industrial and commercial temperature ranges (0°C to 125°C), the LD1117DTTR is fully compatible.

Voltage Range Compatibility: The LD1117DTTR supports a wider input voltage range (15V maximum vs. 7V maximum) and broader adjustable output voltage range (1.25V to 15V vs. 2.5V to 3.6V). This expanded specification range ensures compatibility with the IRU1117CD's operating envelope while providing design flexibility for future applications.

Frequently Asked Questions (FAQ)

Q: Can the LD1117DTTR directly replace the IRU1117CD without PCB modifications?

A: Yes. Both devices use identical DPAK (TO-252-3) packaging with matching pin configurations. Direct substitution on existing PCBs is mechanically and electrically feasible without layout changes.

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

A: The primary differences are product status (obsolete vs. active), regulatory compliance (RoHS non-compliant vs. ROHS3 compliant), and electrical performance enhancements in the LD1117DTTR including lower quiescent current, improved PSRR, and reduced dropout voltage. The LD1117DTTR also supports a wider input voltage range and broader output voltage adjustment range.

Q: Is the LD1117DTTR suitable for applications requiring operation above 125°C?

A: No. The LD1117DTTR is rated for operation up to 125°C, while the IRU1117CD extends to 150°C. Applications requiring sustained operation above 125°C must retain the IRU1117CD or identify alternative regulators with higher temperature ratings.

Q: Does the LD1117DTTR meet current environmental regulations?

A: Yes. The LD1117DTTR is ROHS3 compliant, meeting current RoHS requirements. The IRU1117CD is RoHS non-compliant, which may restrict procurement in regulated markets and applications subject to environmental compliance mandates.

Q: How do the quiescent current specifications compare?

A: The LD1117DTTR draws 5mA quiescent current compared to 10mA for the IRU1117CD. This 50% reduction in quiescent current improves efficiency in battery-powered or low-power standby applications.

Q: Are there any output voltage range limitations when substituting?

A: The LD1117DTTR supports adjustable output from 1.25V to 15V, which encompasses the IRU1117CD's 2.5V to 3.6V range. No output voltage range limitations exist for standard substitution. The LD1117DTTR's broader range provides additional design flexibility.

Q: What is the impact of the lower dropout voltage in the LD1117DTTR?

A: The LD1117DTTR exhibits 1.2V dropout at 800mA versus 1.3V at 1A for the IRU1117CD. Lower dropout voltage improves power efficiency and allows operation with lower input voltages, benefiting battery-powered and low-voltage applications.

Q: Is the LD1117DTTR available in the same packaging options?

A: The LD1117DTTR is supplied in DPAK packaging, matching the IRU1117CD. Both devices are surface mount components with identical footprints and pin configurations.