FMMT625TC Equivalent & Substitute Parts

Part Overview

The FMMT625TC is a Surface Mount NPN Bipolar Junction Transistor (BJT) manufactured by Diodes Incorporated, designed for high-voltage switching and amplification applications. This device operates at 150 V collector-emitter breakdown voltage with a maximum collector current of 1 A and 625 mW power dissipation capability. The FMMT625TC is classified as obsolete, necessitating identification of active equivalent and substitute components for new designs and ongoing production requirements. Equivalent parts maintain identical electrical and mechanical specifications, while substitute parts provide functional alternatives with modified performance parameters suitable for specific application requirements.

Substiute Parts

FMMT625TC

Diodes IncorporatedIn Stock: 950FMMT625TC Datasheet

Current PartRFQ

FMMT625QTA

Diodes IncorporatedIn Stock: 808FMMT625QTA Datasheet

Parametric EquivalentRFQ

FMMT625TA

Diodes IncorporatedIn Stock: 24381FMMT625TA Datasheet

Parametric EquivalentRFQ

MMBT2484LT1G

onsemiIn Stock: 9298MMBT2484LT1G Datasheet

MFR RecommendedRFQ

MMBT2484LT3G

onsemiIn Stock: 30521MMBT2484LT3G Datasheet

MFR RecommendedRFQ

MMBT3904LT1G

onsemiIn Stock: 605202MMBT3904LT1G Datasheet

MFR RecommendedRFQ

MMBT3904LT3G

onsemiIn Stock: 360379MMBT3904LT3G Datasheet

MFR RecommendedRFQ

MMBT6429LT1G

onsemiIn Stock: 155261MMBT6429LT1G Datasheet

MFR RecommendedRFQ

SMMBT3904LT1G

onsemiIn Stock: 287321SMMBT3904LT1G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FMMT625TC is determined by alignment of critical electrical parameters: collector-emitter breakdown voltage, maximum collector current, power dissipation, transition frequency, and saturation voltage characteristics. The SOT-23-3 package requirement is mandatory for mechanical compatibility with existing PCB layouts.

Parametric Equivalent Classification: Parts maintaining identical specifications across all electrical parameters (150 V breakdown, 1 A collector current, 625 mW power, 135 MHz transition frequency, and 300 mV saturation voltage) are classified as parametric equivalents. These parts are direct replacements with no circuit redesign required.

Manufacturer Recommended Substitute Classification: Parts with reduced electrical ratings (lower breakdown voltage, reduced collector current, or lower power dissipation) are classified as manufacturer recommended substitutes. These parts require circuit analysis to confirm suitability for the specific application. Substitution is valid only when application requirements do not exceed the substitute part's maximum ratings.

Key Parameters for Substitution Determination:

• Voltage - Collector Emitter Breakdown (Max)
• Current - Collector (Ic) (Max)
• Power - Max
• Frequency - Transition
• Vce Saturation characteristics
• Package / Case (SOT-23-3 mandatory)

Parameter Comparison

Engineering Selection Recommendations

Parametric Equivalent Selection (Direct Replacement):

FMMT625TA and FMMT625QTA are parametric equivalents of the FMMT625TC. Both parts maintain identical electrical specifications (150 V breakdown voltage, 1 A collector current, 625 mW power dissipation, 135 MHz transition frequency) and are manufactured by Diodes Incorporated. Both parts are classified as Active products with ROHS3 compliance and REACH unaffected status. FMMT625TA is available in Cut Tape & Digi-Reel packaging with 24,345 pieces in stock. FMMT625QTA is available in Tape & Reel packaging with automotive qualification (AEC-Q101) and 735 pieces in stock. Selection between these two equivalents depends on packaging requirements and supply chain preferences.

Manufacturer Recommended Substitute Selection:

MMBT3904LT1G, MMBT3904LT3G, and SMMBT3904LT1G are manufacturer recommended substitutes manufactured by onsemi. These parts operate at reduced voltage ratings (40 V breakdown versus 150 V) and reduced current ratings (200 mA versus 1 A). These substitutes are suitable for applications where the FMMT625TC's high-voltage capability is not required. SMMBT3904LT1G includes automotive qualification (AEC-Q101). All three variants are Active products with ROHS3 compliance.

MMBT2484LT1G and MMBT2484LT3G are manufacturer recommended substitutes with further reduced ratings (60 V breakdown, 100 mA collector current, 225 mW power). These parts are suitable only for low-voltage, low-current applications.

MMBT6429LT1G is a manufacturer recommended substitute with 45 V breakdown voltage and 200 mA collector current. This part features higher transition frequency (700 MHz) and is suitable for high-frequency applications with reduced voltage requirements.

All substitute parts maintain SOT-23-3 package compatibility and operating temperature range (-55°C to 150°C).

Frequently Asked Questions (FAQ)

Q: Can FMMT625TA be used as a direct replacement for FMMT625TC?

A: Yes. FMMT625TA is a parametric equivalent with identical electrical specifications. The primary difference is product status (Active versus Obsolete) and packaging format (Cut Tape & Digi-Reel versus unspecified). No circuit modifications are required.

Q: What is the difference between FMMT625TA and FMMT625QTA?

A: Both are parametric equivalents with identical electrical specifications. FMMT625QTA includes automotive qualification (AEC-Q101 series designation) and is supplied in Tape & Reel packaging. FMMT625TA is supplied in Cut Tape & Digi-Reel packaging. Selection depends on packaging requirements and automotive compliance needs.

Q: Can MMBT3904LT1G replace FMMT625TC in all applications?

A: No. MMBT3904LT1G has reduced electrical ratings: 40 V breakdown voltage (versus 150 V), 200 mA collector current (versus 1 A), and 300 mW power dissipation (versus 625 mW). Substitution is valid only when the application circuit operates within these reduced limits. Circuit analysis is required to confirm compatibility.

Q: Why do MMBT3904 variants have different part numbers (LT1G, LT3G)?

A: The suffix designates packaging format and tape configuration. LT1G indicates Cut Tape & Digi-Reel packaging. LT3G indicates alternative tape configuration. Electrical specifications are identical between variants. Selection depends on supply chain and assembly equipment compatibility.

Q: Is SMMBT3904LT1G suitable for automotive applications?

A: Yes. SMMBT3904LT1G includes automotive qualification (AEC-Q101) designation. However, the reduced electrical ratings (40 V breakdown, 200 mA current) must be confirmed compatible with the specific automotive application requirements.

Q: What is the significance of the SOT-23-3 package requirement?

A: SOT-23-3 is the mechanical package standard for all listed parts. This package designation ensures physical and electrical compatibility with existing PCB layouts and assembly processes. All substitute parts maintain this package standard.

Q: Can MMBT6429LT1G be used in high-frequency applications?

A: MMBT6429LT1G features 700 MHz transition frequency (versus 135 MHz for FMMT625TC), making it suitable for higher-frequency applications. However, the reduced voltage rating (45 V versus 150 V) and reduced current rating (200 mA versus 1 A) must be confirmed compatible with the specific application requirements.

Q: Are all listed parts RoHS3 compliant?

A: Yes. All parts listed are ROHS3 compliant and REACH unaffected, meeting environmental and regulatory requirements for commercial and industrial applications.

Q: What inventory considerations apply to part selection?

A: FMMT625TA has the highest inventory availability (24,345 pieces), followed by MMBT3904LT3G (360,300 pieces) and MMBT3904LT1G (605,100 pieces). FMMT625QTA has limited availability (735 pieces). Inventory levels should be considered in long-term supply chain planning.