STL55NH3LL N-Channel 30V 55A MOSFET Equivalent & Substitute Parts

Part Overview

The STL55NH3LL is an N-Channel 30V 55A MOSFET manufactured by STMicroelectronics in the STripFET™ series. This device is rated for continuous drain current of 55A at Tc with 60W maximum power dissipation in a PowerFlat™ (5x6) surface mount package. The part is currently obsolete, necessitating identification of functionally equivalent alternatives from active product lines that maintain electrical and mechanical compatibility for direct board-level substitution.

Substiute Parts

STL55NH3LL

STMicroelectronicsIn Stock: 25893STL55NH3LL Datasheet

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AON6414A

Alpha & Omega Semiconductor Inc.In Stock: 5086AON6414A Datasheet

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BSC090N03LSGATMA1

Infineon TechnologiesIn Stock: 23556BSC090N03LSGATMA1 Datasheet

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CSD17302Q5A

Texas InstrumentsIn Stock: 14578CSD17302Q5A Datasheet

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CSD17307Q5A

Texas InstrumentsIn Stock: 20031CSD17307Q5A Datasheet

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CSD17322Q5A

Texas InstrumentsIn Stock: 16283CSD17322Q5A Datasheet

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CSD17507Q5A

Texas InstrumentsIn Stock: 17913CSD17507Q5A Datasheet

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CSD17522Q5A

Texas InstrumentsIn Stock: 18976CSD17522Q5A Datasheet

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CSD17527Q5A

Texas InstrumentsIn Stock: 32683CSD17527Q5A Datasheet

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RS1E150GNTB

Rohm SemiconductorIn Stock: 1877RS1E150GNTB Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the STL55NH3LL is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Drain to Source Voltage (Vdss): 30V minimum
• Continuous Drain Current (Id): 55A or greater at Tc
• Gate-Source Voltage (Vgs) range: ±16V or greater
• Operating temperature range: -55°C to 150°C or greater
• RoHS3 compliance and MSL 1 rating

Mechanical Compatibility Criteria:

• Surface mount package with 8-pin configuration
• Physical footprint: 5x6mm or compatible
• PowerFlat™ or equivalent power dissipation package class

Substitute parts are grouped into two categories based on their continuous drain current capability relative to the original 55A specification:

Category A – Full Current Equivalents (≥55A Tc): Parts meeting or exceeding 55A continuous drain current at Tc, providing direct functional replacement with equivalent or superior current handling.

Category B – Reduced Current Alternatives (30A–54A Tc): Parts with continuous drain current between 30A and 54A at Tc, suitable for applications where the full 55A capability is not required but electrical characteristics remain compatible.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Full Current Equivalents):

CSD17322Q5A, CSD17522Q5A, and CSD17527Q5A from Texas Instruments NexFET™ series are the preferred substitutes. These parts exceed the 55A continuous drain current requirement with ratings of 87A, 87A, and 65A respectively at Tc. All three maintain 30V Vdss rating, operate across -55°C to 150°C, and are ROHS3 compliant with MSL 1 rating. The 8-VSONP (5x6) package footprint is mechanically compatible with the original PowerFlat™ (5x6) package. CSD17322Q5A and CSD17522Q5A offer superior gate charge characteristics (4.3 nC) compared to the original 12 nC specification, resulting in faster switching performance.

Secondary Substitutes (Reduced Current Alternatives):

CSD17302Q5A and CSD17307Q5A from Texas Instruments provide 87A and 73A continuous drain current respectively, with improved gate charge performance (7 nC and 5.2 nC). BSC090N03LSGATMA1 from Infineon Technologies OptiMOS™ series delivers 48A continuous drain current with compatible electrical characteristics. These alternatives are suitable for applications where the full 55A capability is not required.

Lower Current Alternatives:

AON6414A (Alpha & Omega Semiconductor Inc., 30A Tc) and RS1E150GNTB (Rohm Semiconductor, 40A Tc) are available for applications with reduced current demands. Both maintain 30V Vdss and full temperature range compatibility.

Compliance and Certification:

All substitute parts listed are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating, matching the original part's environmental specifications. CSD17302Q5A and CSD17522Q5A carry REACH Affected status; all others are REACH Unaffected. All parts are classified under ECCN EAR99 and HTSUS 8541.29.0095.

Frequently Asked Questions (FAQ)

Q: Can CSD17322Q5A directly replace STL55NH3LL on the PCB?

A: The CSD17322Q5A is electrically compatible and meets all electrical requirements. The 8-VSONP (5x6) package footprint is mechanically compatible with the original PowerFlat™ (5x6) package. Pin configuration must be verified against the original design schematic to confirm gate, drain, and source connections.

Q: What is the difference between the Texas Instruments NexFET™ parts listed?

A: The primary differences are continuous drain current ratings and gate charge characteristics. CSD17322Q5A and CSD17522Q5A both provide 87A at Tc with 4.3 nC gate charge. CSD17527Q5A provides 65A at Tc with 3.4 nC gate charge. CSD17302Q5A provides 87A at Tc with 7 nC gate charge. CSD17307Q5A provides 73A at Tc with 5.2 nC gate charge. Selection depends on application current requirements and switching speed needs.

Q: Are there package differences between substitute parts?

A: Yes. Most Texas Instruments substitutes use 8-VSONP (5x6) package. Infineon BSC090N03LSGATMA1 uses PG-TDSON-8-5 package. Alpha & Omega AON6414A uses 8-DFN (5x6) package. Rohm RS1E150GNTB uses 8-HSOP package. All are 8-pin surface mount packages with 5x6mm footprints, but PCB layout verification is required before substitution.

Q: What is the significance of gate charge (Qg) differences?

A: Gate charge affects switching speed and driver circuit requirements. The original STL55NH3LL has 12 nC gate charge at 4.5V. Texas Instruments NexFET™ parts have significantly lower gate charge (3.4–7 nC), enabling faster switching. Alpha & Omega AON6414A has higher gate charge (24 nC), requiring longer switching times. Driver circuit compatibility must be evaluated based on application switching frequency.

Q: Which substitute is recommended for new designs?

A: CSD17322Q5A or CSD17522Q5A from Texas Instruments are recommended for new designs. Both provide 87A continuous drain current, superior gate charge performance, active product status, and full compliance certifications. The choice between these two depends on drive voltage requirements: CSD17322Q5A operates with 4.5V/8V drive voltages, while CSD17522Q5A operates with 4.5V/10V drive voltages.

Q: Is the STL55NH3LL still available for purchase?

A: The STL55NH3LL is listed as obsolete. Inventory of 25,844 pieces is reported as new original stock, but availability through distributors should be confirmed. For new production, active substitute parts are recommended to ensure long-term supply chain continuity.

Q: What are the thermal considerations when substituting?

A: All substitute parts maintain the -55°C to 150°C operating temperature range of the original. Power dissipation varies: STL55NH3LL is rated 60W (Tc), while most Texas Instruments substitutes are rated 3W (Ta). Thermal management design must account for actual application current levels and duty cycles. PCB thermal design and heatsinking requirements should be re-evaluated based on the selected substitute part's thermal characteristics.

Q: Can I use AON6414A or RS1E150GNTB if my application only requires 30–40A?

A: Yes. AON6414A (30A Tc) and RS1E150GNTB (40A Tc) are suitable for applications with reduced current requirements. Both maintain 30V Vdss, full temperature range, and compliance certifications. However, verify that the reduced continuous current rating meets your application's sustained current demands under worst-case operating conditions.