MMBT3904SL Equivalent & Substitute Parts

Part Overview

The MMBT3904SL is a Surface Mount NPN Bipolar Junction Transistor manufactured by onsemi, housed in a SOT-923F package. This device is rated for 40 V collector-emitter breakdown voltage with a maximum collector current of 200 mA and operates at frequencies up to 300 MHz. The part is classified as Obsolete, necessitating identification of equivalent and substitute components for new designs and ongoing production requirements. Substitute parts maintain electrical compatibility while offering active product status and improved availability.

Substiute Parts

MMBT3904SL

onsemiIn Stock: 56136MMBT3904SL Datasheet

Current PartRFQ

NST3904F3T5G

onsemiIn Stock: 306646NST3904F3T5G Datasheet

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MMBT3904TT1G

onsemiIn Stock: 151697MMBT3904TT1G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MMBT3904SL is determined by strict electrical and mechanical parameter matching. All substitute parts maintain identical collector current (200 mA maximum), collector-emitter breakdown voltage (40 V), saturation voltage characteristics (300 mV @ 5 mA, 50 mA), and DC current gain specifications (100 @ 10 mA, 1 V). These parameters define functional equivalence for NPN transistor applications.

Substitute parts are grouped into two categories:

Direct Manufacturer Substitute (NST3904F3T5G): Maintains all critical electrical specifications with identical saturation and gain characteristics. Package differs (SOT-1123 versus SOT-923F), requiring PCB layout modification. Product status is Active with RoHS3 compliance.

Similar Manufacturer Substitute (MMBT3904TT1G): Maintains all critical electrical specifications with identical saturation and gain characteristics. Package differs (SC-75/SOT-416 versus SOT-923F), requiring PCB layout modification. Product status is Active with RoHS3 compliance and higher maximum power rating (300 mW).

All substitutes are manufactured by onsemi, share the MMBT3904/NST3904 base product lineage, and maintain MSL 1 (Unlimited) moisture sensitivity classification.

Parameter Comparison

Engineering Selection Recommendations

For Direct Electrical Substitution with Package Change:

NST3904F3T5G is the direct electrical equivalent of MMBT3904SL. This part maintains all critical electrical parameters including collector current, breakdown voltage, saturation characteristics, and DC current gain. The substitute offers Active product status with ROHS3 compliance, ensuring long-term availability and regulatory alignment. The SOT-1123 package requires PCB layout modification from the original SOT-923F footprint. Transition frequency is reduced to 200 MHz compared to the original 300 MHz specification; applications requiring frequencies above 200 MHz must use MMBT3904TT1G.

For Highest Electrical Performance with Package Change:

MMBT3904TT1G maintains all critical electrical parameters and preserves the 300 MHz transition frequency of the original MMBT3904SL. This part offers the highest maximum power rating (300 mW) among available substitutes and Active product status with ROHS3 compliance. The SC-75/SOT-416 package requires PCB layout modification from the original SOT-923F footprint.

Both substitute parts are manufactured by onsemi, carry identical REACH and ECCN classifications, and maintain unlimited moisture sensitivity levels. Selection between substitutes depends on package compatibility with existing PCB designs and frequency requirements of the target application.

Frequently Asked Questions (FAQ)

Q: Can NST3904F3T5G replace MMBT3904SL in all applications?

A: NST3904F3T5G maintains electrical equivalence for all specified parameters except transition frequency. Applications operating at frequencies below 200 MHz are fully compatible. Applications requiring 300 MHz operation must use MMBT3904TT1G. PCB layout modification is required due to package change from SOT-923F to SOT-1123.

Q: What is the primary difference between the two substitute parts?

A: NST3904F3T5G uses SOT-1123 packaging with 200 MHz transition frequency and 290 mW maximum power. MMBT3904TT1G uses SC-75/SOT-416 packaging with 300 MHz transition frequency and 300 mW maximum power. Both maintain identical collector current, breakdown voltage, saturation voltage, and DC current gain specifications.

Q: Are package changes between MMBT3904SL and substitute parts interchangeable on existing PCBs?

A: No. MMBT3904SL uses SOT-923F package. NST3904F3T5G uses SOT-1123 package. MMBT3904TT1G uses SC-75/SOT-416 package. Each package has different pin configurations and footprints. PCB layout and footprint modification is required for any substitution.

Q: Do substitute parts meet current regulatory requirements?

A: Yes. Both NST3904F3T5G and MMBT3904TT1G are ROHS3 compliant and REACH unaffected. Both carry Active product status, ensuring regulatory alignment and long-term availability.

Q: What is the impact of reduced transition frequency in NST3904F3T5G?

A: NST3904F3T5G operates at 200 MHz maximum transition frequency compared to 300 MHz for MMBT3904SL and MMBT3904TT1G. Applications with switching frequencies or signal frequencies below 200 MHz are unaffected. High-frequency applications above 200 MHz require MMBT3904TT1G.

Q: Are moisture sensitivity levels identical across all parts?

A: Yes. MMBT3904SL, NST3904F3T5G, and MMBT3904TT1G all carry MSL 1 (Unlimited) classification, indicating no moisture sensitivity restrictions for storage, handling, or reflow processes.