LLSD103B-7 Equivalent & Substitute Parts

Part Overview

The LLSD103B-7 is a Schottky diode manufactured by Diodes Incorporated, rated for 30 V DC reverse voltage with 350 mA average rectified current. The device is packaged in a DO-213AC Mini MELF surface mount configuration and is designed for fast recovery applications with a reverse recovery time of 10 ns. The LLSD103B-7 is classified as obsolete, necessitating identification of active equivalent and substitute parts for ongoing design and procurement requirements. Substitute parts must maintain electrical compatibility while accommodating available packaging and current rating variations.

Substiute Parts

LLSD103B-7

Diodes IncorporatedIn Stock: 1103LLSD103B-7 Datasheet

Current PartRFQ

SD103BW-7-F

Diodes IncorporatedIn Stock: 17673SD103BW-7-F Datasheet

MFR RecommendedRFQ

BAS85,115

Nexperia USA Inc.In Stock: 235206BAS85,115 Datasheet

MFR RecommendedRFQ

BAS85,135

Nexperia USA Inc.In Stock: 4485BAS85,135 Datasheet

MFR RecommendedRFQ

TMMBAT42FILM

STMicroelectronicsIn Stock: 42789TMMBAT42FILM Datasheet

MFR RecommendedRFQ

TMMBAT43FILM

STMicroelectronicsIn Stock: 23622TMMBAT43FILM Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LLSD103B-7 is determined by the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

• Voltage - DC Reverse (Vr) (Max): 30 V minimum
• Technology: Schottky diode
• Mounting Type: Surface Mount
• Forward voltage and reverse recovery characteristics compatible with application requirements

Secondary Considerations:

• Current - Average Rectified (Io): Rated current must equal or exceed 350 mA for direct replacement; lower-rated devices (200 mA) are acceptable only when circuit design permits reduced current capacity
• Package / Case: DO-213AC Mini MELF is the original package; SOD-123 and DO-213AA alternatives are mechanically compatible with surface mount assembly processes
• Operating Temperature Range: Minimum junction temperature rating of -55°C and maximum of 125°C required

Substitute parts are grouped into two categories:

Category 1 - Direct Electrical Replacement (350 mA Rating): SD103BW-7-F maintains the 350 mA current rating and 30 V reverse voltage specification. This part is the primary recommended substitute due to active product status and identical electrical performance.

Category 2 - Functional Substitutes (200 mA Rating): BAS85,115, BAS85,135, TMMBAT42FILM, and TMMBAT43FILM are rated for 200 mA average rectified current. These parts are acceptable substitutes only when circuit design accommodates the reduced current capacity. All maintain 30 V reverse voltage rating and Schottky technology.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: SD103BW-7-F

The SD103BW-7-F is the manufacturer-recommended substitute for the LLSD103B-7. This part maintains identical electrical specifications including 30 V reverse voltage, 350 mA average rectified current, and 600 mV forward voltage at 200 mA. The SD103BW-7-F is manufactured by Diodes Incorporated and carries active product status, ensuring long-term availability and supply chain stability. The part is ROHS3 compliant and REACH unaffected, providing regulatory compliance advantages over the original obsolete part. The primary packaging difference is SOD-123 versus the original DO-213AC Mini MELF; both are standard surface mount packages compatible with modern assembly processes. Inventory availability of 17,660 pieces supports immediate procurement.

Secondary Recommendations: BAS85,115 and BAS85,135

The BAS85,115 and BAS85,135 parts are functionally equivalent Schottky diodes manufactured by Nexperia USA Inc. Both maintain the 30 V reverse voltage rating and are available in the original DO-213AC Mini MELF package. These parts are rated for 200 mA average rectified current, which is lower than the original 350 mA specification. Selection of these parts is appropriate only when circuit design analysis confirms that the reduced current capacity does not compromise application performance. Both parts are ROHS3 compliant and REACH unaffected. BAS85,115 is available in Cut Tape & Digi-Reel packaging with 235,100 pieces in stock; BAS85,135 is available in Tape & Reel packaging with 4,390 pieces in stock.

Tertiary Recommendations: TMMBAT42FILM and TMMBAT43FILM

The TMMBAT42FILM and TMMBAT43FILM are Schottky diodes manufactured by STMicroelectronics, both rated for 30 V reverse voltage and 200 mA average rectified current. These parts feature superior reverse recovery time (5 ns versus 10 ns) and significantly lower reverse leakage current (500 nA versus 5 µA). The package is DO-213AA (Glass) Mini MELF, which differs from the original DO-213AC package but remains compatible with surface mount assembly. Forward voltage is specified at 1 V @ 200 mA, which is higher than the original 600 mV specification. Both parts are ROHS3 compliant and REACH unaffected. TMMBAT42FILM has 42,700 pieces in stock; TMMBAT43FILM has 23,600 pieces in stock. Selection of these parts is appropriate when the reduced current capacity and higher forward voltage are acceptable to circuit design requirements.

Frequently Asked Questions (FAQ)

Q: Can SD103BW-7-F be used as a direct replacement for LLSD103B-7?

A: Yes. The SD103BW-7-F maintains identical electrical specifications including 30 V reverse voltage, 350 mA average rectified current, 600 mV forward voltage at 200 mA, and 10 ns reverse recovery time. The primary difference is packaging: SD103BW-7-F uses SOD-123 instead of the original DO-213AC Mini MELF. Both are surface mount packages compatible with standard assembly processes. SD103BW-7-F is the manufacturer-recommended substitute.

Q: What is the difference between the 350 mA and 200 mA rated parts?

A: The LLSD103B-7 and SD103BW-7-F are rated for 350 mA average rectified current. The BAS85,115, BAS85,135, TMMBAT42FILM, and TMMBAT43FILM parts are rated for 200 mA. The current rating indicates the maximum continuous forward current the diode can conduct. Selection of 200 mA parts requires circuit design analysis to confirm that application current requirements do not exceed this limit.

Q: Are the package differences between DO-213AC and SOD-123 significant?

A: Both DO-213AC Mini MELF and SOD-123 are standard surface mount packages. The primary difference is physical size and lead configuration. SOD-123 is smaller than Mini MELF. PCB layout and assembly equipment compatibility must be verified before substitution. Both packages are widely supported by modern surface mount assembly processes.

Q: Why do the TMMBAT42FILM and TMMBAT43FILM parts have lower reverse leakage current?

A: Reverse leakage current is a device characteristic determined by semiconductor material quality and manufacturing process. TMMBAT42FILM and TMMBAT43FILM specify 500 nA @ 25 V compared to 5 µA @ 20 V for the original part. Lower reverse leakage current is a performance advantage in applications sensitive to leakage, but it does not affect basic substitution compatibility.

Q: What does REACH Unaffected status mean for substitute parts?

A: REACH Unaffected status indicates that the substitute part does not contain substances of very high concern (SVHC) listed under the REACH regulation. The original LLSD103B-7 is REACH Affected, meaning it may contain listed substances. All recommended substitute parts are REACH Unaffected, providing regulatory compliance advantages for new designs and procurement.

Q: Can BAS85,115 and BAS85,135 be used interchangeably?

A: Yes. BAS85,115 and BAS85,135 are electrically identical Schottky diodes with the same 30 V reverse voltage and 200 mA current ratings. The primary difference is packaging: BAS85,115 is supplied in Cut Tape & Digi-Reel format; BAS85,135 is supplied in Tape & Reel format. Selection depends on procurement and assembly process requirements.

Q: What is the significance of the forward voltage difference between substitute parts?

A: Forward voltage (Vf) is the voltage drop across the diode when conducting forward current. The original LLSD103B-7 specifies 600 mV @ 200 mA. BAS85,115 and BAS85,135 specify 800 mV @ 100 mA; TMMBAT42FILM and TMMBAT43FILM specify 1 V @ 200 mA. Higher forward voltage results in greater power dissipation. Circuit design analysis must confirm that the substitute part's forward voltage is acceptable for the application.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. The LLSD103B-7 and all recommended substitute parts are ROHS3 compliant, indicating compliance with the Restriction of Hazardous Substances Directive. This compliance status is maintained across all substitute options.

Q: What is the operating temperature range difference between parts?

A: The LLSD103B-7 specifies -55°C to 125°C junction temperature. SD103BW-7-F, TMMBAT42FILM, and TMMBAT43FILM specify -65°C to 125°C, providing extended low-temperature operation. BAS85,115 and BAS85,135 specify 125°C maximum without a minimum temperature specification. Circuit design requirements determine whether extended temperature range is necessary.