LM2831YSD Equivalent & Substitute Parts

Part Overview

The LM2831YSD is a buck switching regulator IC from Texas Instruments designed for positive adjustable output applications. It delivers 1.5A output current with an adjustable voltage range from 0.6V to 4.5V, operating from a 3V to 5.5V input supply. The device is classified as obsolete, which necessitates identification of equivalent and substitute parts for new designs or production continuity. Alternative components must maintain functional compatibility while meeting current manufacturing and compliance standards.

Substiute Parts

LM2831YSD

Texas InstrumentsIn Stock: 6120LM2831YSD Datasheet

Current PartRFQ

LM2831YSD/NOPB

Texas InstrumentsIn Stock: 756LM2831YSD/NOPB Datasheet

DirectRFQ

ST1S09IPUR

STMicroelectronicsIn Stock: 6799ST1S09IPUR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LM2831YSD are identified based on the following critical parameters that determine functional compatibility:

Primary Compatibility Criteria:

• Function: Step-Down (Buck) topology
• Output Configuration: Positive adjustable output
• Number of Outputs: Single output
• Mounting Type: Surface Mount
• Package Type: 6-pin DFN/WSON form factor with exposed pad

Electrical Operating Range:

• Input voltage range must encompass or exceed 3V to 5.5V
• Output voltage adjustability must support minimum 0.6V to maximum 4.5V range
• Output current capability must meet or exceed 1.5A

Compliance & Status:

• Active product status preferred for long-term availability
• RoHS3 compliance required for new designs
• Operating temperature range should support -40°C to 125°C or equivalent industrial range

Two substitute parts meet these criteria with varying performance enhancements.

Parameter Comparison

Engineering Selection Recommendations

LM2831YSD/NOPB (Direct Equivalent)

The LM2831YSD/NOPB is the direct equivalent of the LM2831YSD, differing only in packaging format (Tape & Reel versus bulk) and product status. It maintains identical electrical specifications, including input voltage range (3V to 5.5V), output voltage adjustability (0.6V to 4.5V), and 1.5A output current. The primary advantage is active product status with RoHS3 compliance, making it suitable for new production and long-term availability. Moisture sensitivity level remains at MSL 3, requiring standard handling precautions. This part is the preferred choice for direct replacement in existing designs.

ST1S09IPUR (Enhanced Substitute)

The ST1S09IPUR from STMicroelectronics provides enhanced performance characteristics while maintaining functional compatibility. It delivers higher output current (2A versus 1.5A), operates at a higher switching frequency (1.5MHz versus 550kHz), and includes an integrated synchronous rectifier for improved efficiency. The input voltage range is slightly wider (2.7V to 6V), and output voltage range extends to 5.22V. Operating temperature range is -30°C to 85°C, which is narrower than the original part. The device features superior moisture sensitivity (MSL 1, unlimited storage). This part is suitable for applications requiring higher current capacity or improved thermal performance, provided the narrower temperature range is acceptable.

Frequently Asked Questions (FAQ)

Q: Can LM2831YSD/NOPB be used as a direct replacement for LM2831YSD?

A: Yes. The LM2831YSD/NOPB is electrically and functionally identical to the LM2831YSD. The difference is packaging format and product status. LM2831YSD/NOPB is active and RoHS3 compliant, making it the recommended choice for new designs and production continuity.

Q: What are the key differences between LM2831YSD and ST1S09IPUR?

A: The ST1S09IPUR offers higher output current (2A versus 1.5A), higher switching frequency (1.5MHz versus 550kHz), and includes a synchronous rectifier. Input voltage range is slightly wider (2.7V to 6V). The operating temperature range is narrower (-30°C to 85°C versus -40°C to 125°C), and moisture sensitivity is superior (MSL 1 versus MSL 3). Both maintain adjustable positive output topology in 6-pin DFN packages.

Q: Is the ST1S09IPUR package compatible with LM2831YSD PCB layouts?

A: Both devices use 6-pin DFN exposed pad packages (6-WSON and 6-VDFN respectively) with 3x3mm form factors. Physical footprints are compatible for PCB placement. However, pin configuration and internal circuitry differ, requiring schematic and layout verification before substitution.

Q: What is the impact of the narrower operating temperature range of ST1S09IPUR?

A: The ST1S09IPUR operates from -30°C to 85°C, compared to LM2831YSD at -40°C to 125°C. If your application requires operation below -30°C or above 85°C, the ST1S09IPUR is not suitable. For standard industrial and commercial temperature ranges, this difference is typically not limiting.

Q: Why is RoHS compliance important for substitute selection?

A: RoHS3 compliance is mandatory for new product designs and production in most markets. The original LM2831YSD is RoHS non-compliant, making it unsuitable for new applications. Both substitute parts (LM2831YSD/NOPB and ST1S09IPUR) are RoHS3 compliant, ensuring regulatory compliance and long-term market availability.

Q: What does MSL 1 versus MSL 3 mean for component handling?

A: MSL (Moisture Sensitivity Level) indicates storage and handling requirements. MSL 3 requires storage at controlled humidity (168-hour floor life after opening), while MSL 1 has unlimited floor life. ST1S09IPUR (MSL 1) offers superior handling flexibility and lower risk of moisture-related failures during assembly.