STR2550 Equivalent & Substitute Parts

Part Overview

The STR2550 is an active PNP bipolar junction transistor manufactured by STMicroelectronics, designed for surface mount applications in the SOT-23-3 package. This component operates at 500 V collector-emitter breakdown voltage with a maximum collector current of 500 mA and 500 mW power dissipation. The part is ROHS3 compliant with unlimited moisture sensitivity level (MSL 1) and is currently in active production status with 3300 units in stock. Equivalent and substitute parts are identified to support design flexibility, inventory management, and supply chain continuity for applications requiring PNP transistor functionality within specified electrical and mechanical parameters.

Substiute Parts

STR2550

STMicroelectronicsIn Stock: 3407STR2550 Datasheet

Current PartRFQ

FMMT560QTA

Diodes IncorporatedIn Stock: 15745FMMT560QTA Datasheet

SimilarRFQ

FMMT560QTC

Diodes IncorporatedIn Stock: 878FMMT560QTC Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the STR2550 are qualified based on the following electrical and mechanical parameters:

Critical Matching Parameters:

• Transistor Type: PNP configuration
• Voltage - Collector Emitter Breakdown: 500 V (maximum rating)
• Package / Case: SOT-23-3 (mechanical and thermal compatibility)
• Mounting Type: Surface Mount
• RoHS Status: ROHS3 Compliant

Allowable Variation Parameters:

• Current - Collector (Ic) (Max): Substitute parts may have lower maximum ratings provided the application current requirement does not exceed the substitute part's specification
• Power - Max: 500 mW (maintained across all qualified substitutes)
• Vce Saturation: Variations permitted within application switching requirements
• DC Current Gain (hFE): Variations permitted provided minimum gain meets circuit design requirements
• Operating Temperature Range: Substitutes may have extended temperature ranges

The FMMT560QTA and FMMT560QTC from Diodes Incorporated meet these substitution criteria with identical voltage and power ratings, matching package specifications, and equivalent RoHS compliance.

Parameter Comparison

Engineering Selection Recommendations

STR2550 (Primary Selection) Select the STR2550 when maximum collector current of 500 mA is required within the application design. This part is active in production with substantial inventory availability (3300 units). The STR2550 provides the lowest saturation voltage (300 mV) at specified test conditions, supporting applications requiring minimal voltage drop across the transistor in saturation mode.

FMMT560QTA (General Substitute) The FMMT560QTA is suitable for applications where collector current requirements do not exceed 150 mA. This part maintains identical voltage and power ratings with ROHS3 compliance and unlimited MSL rating. The FMMT560QTA is available in higher inventory (15720 units) and provides extended frequency response (60 MHz transition frequency). Selection is appropriate for general-purpose switching and amplification circuits operating within the 150 mA current specification.

FMMT560QTC (Automotive-Grade Substitute) The FMMT560QTC is qualified to AEC-Q101 automotive standards and carries automotive-grade designation. This part is suitable for applications requiring automotive qualification or operating in automotive environments. Like the FMMT560QTA, it operates within 150 mA maximum collector current and maintains all critical electrical parameters including 500 V breakdown voltage and 500 mW power dissipation. Selection is mandatory for automotive applications requiring AEC-Q101 compliance.

Substitution Constraints Substitution from STR2550 to either FMMT560 variant requires verification that application collector current does not exceed 150 mA. The higher saturation voltage of FMMT560 devices (500 mV versus 300 mV) must be evaluated in saturation-mode applications. Both FMMT560 variants provide superior leakage current performance (100 nA versus 10 µA) and are suitable for low-power standby applications.

Frequently Asked Questions (FAQ)

Q: Can the FMMT560QTA or FMMT560QTC be used as direct replacements for the STR2550?

A: Direct substitution is possible only when application collector current does not exceed 150 mA. Both FMMT560 variants maintain the 500 V breakdown voltage and SOT-23-3 package compatibility. The higher saturation voltage (500 mV versus 300 mV) must be evaluated for saturation-mode circuit operation.

Q: What is the primary difference between FMMT560QTA and FMMT560QTC?

A: The FMMT560QTC carries automotive-grade designation and AEC-Q101 qualification, making it suitable for automotive applications. Both parts share identical electrical specifications and SOT-23-3 packaging. Selection between these variants depends on automotive qualification requirements.

Q: Are all three parts RoHS compliant?

A: Yes. The STR2550, FMMT560QTA, and FMMT560QTC are all ROHS3 compliant and REACH unaffected, meeting environmental regulatory requirements for commercial and industrial applications.

Q: What is the significance of the 60 MHz transition frequency in the FMMT560 devices?

A: The FMMT560 variants specify 60 MHz transition frequency, indicating higher-frequency capability compared to the STR2550 (which does not specify transition frequency). This parameter is relevant for high-frequency switching and RF applications but does not affect low-frequency switching applications.

Q: How do the leakage current specifications differ between these parts?

A: The STR2550 specifies 10 µA maximum collector cutoff current (ICBO), while both FMMT560 variants specify 100 nA. The FMMT560 devices exhibit significantly lower leakage, making them preferable for low-power standby and precision analog applications where leakage current must be minimized.

Q: Is the STR2550 suitable for applications requiring 500 mA collector current?

A: Yes. The STR2550 is rated for 500 mA maximum collector current. The FMMT560 variants are limited to 150 mA and cannot be substituted in applications requiring the full 500 mA current capability.

Q: What packaging options are available for these parts?

A: All three parts are supplied in SOT-23-3 surface mount package. The STR2550 is available in Cut Tape (CT) and Digi-Reel packaging. The FMMT560QTA and FMMT560QTC are supplied in Tape & Reel (TR) format.