LM309K STEEL Linear Voltage Regulator

Part Overview

The LM309K STEEL is a linear voltage regulator IC from Texas Instruments designed for positive fixed output applications. This through-hole component delivers 1.5A output current at a fixed 5.05V output voltage, making it suitable for power management applications requiring stable regulated voltage. The part is classified as Active product status with full ROHS3 compliance and REACH unaffected designation. Alternative part numbers may be required due to inventory availability, supply chain considerations, or specific packaging requirements from authorized distributors.

Substiute Parts

LM309K STEEL

Texas InstrumentsIn Stock: 1118LM309K STEEL Datasheet

Current PartRFQ

LM309K STEEL/NOPB

Texas InstrumentsIn Stock: 1248LM309K STEEL/NOPB Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM309K STEEL is determined by strict equivalence across the following critical parameters:

• Output voltage specification: 5.05V fixed output
• Output current capability: 1.5A minimum
• Input voltage rating: 25V maximum
• Package type: TO-3 or TO-204AA through-hole configuration
• Quiescent current: 5.2 mA
• Operating temperature range: 0°C ~ 125°C
• Protection features: Over temperature protection
• Regulatory compliance: ROHS3 compliant, REACH unaffected

The LM309K STEEL/NOPB variant qualifies as a parametric equivalent based on identical electrical specifications and package designation. Both parts share the same base product number (LM309) and maintain full compatibility within the specified parameter envelope.

Parameter Comparison

Engineering Selection Recommendations

Both the LM309K STEEL and LM309K STEEL/NOPB maintain Active product status from Texas Instruments, ensuring continued manufacturing support and supply availability. Both variants satisfy ROHS3 compliance requirements and carry REACH unaffected designation, meeting regulatory requirements for industrial and commercial applications.

Selection between these equivalent parts should be based on:

• Distributor inventory and lead time availability
• Packaging format requirements (Tray specification)
• Specific procurement documentation or traceability requirements
• Cost considerations between equivalent stock levels

The NOPB designation indicates lead-free plating compliance, which does not affect electrical or thermal performance characteristics.

Frequently Asked Questions (FAQ)

Q: Are LM309K STEEL and LM309K STEEL/NOPB electrically identical?

A: Yes. Both parts deliver identical electrical performance with 5.05V fixed output, 1.5A output current, and 5.2 mA quiescent current across the 0°C to 125°C operating range.

Q: Can these parts be used interchangeably in circuit designs?

A: Yes. Both parts share identical package designation (TO-3, TO-204AA), pin configuration, and electrical specifications. No circuit modifications are required for substitution.

Q: What does the NOPB suffix indicate?

A: NOPB designates lead-free plating on the component leads, meeting RoHS requirements. This does not alter electrical characteristics or thermal performance.

Q: Are both parts suitable for 25V input applications?

A: Yes. Both parts are rated for maximum input voltage of 25V and maintain 5.05V regulated output across this input range.

Q: What is the significance of the TO-3 package for this regulator?

A: The TO-3 through-hole package provides robust mechanical connection and thermal dissipation suitable for 1.5A output current applications. Both equivalent parts utilize this same package configuration.

Q: Do both parts include over-temperature protection?

A: Yes. Both the LM309K STEEL and LM309K STEEL/NOPB include integrated over-temperature protection as a standard protection feature.