MPSA55G Equivalent & Substitute Parts

Part Overview

The MPSA55G is a PNP bipolar junction transistor manufactured by onsemi, designed for general-purpose switching and amplification applications. This device features a 60 V collector-emitter breakdown voltage rating and 500 mA maximum collector current in a Through Hole TO-92 package. The MPSA55G is classified as obsolete, making identification of functionally equivalent substitute components necessary for ongoing design support and production continuity. Substitute parts must maintain electrical compatibility across key parameters including voltage ratings, current capacity, gain characteristics, and thermal operating range.

Substiute Parts

MPSA55G

onsemiIn Stock: 5187MPSA55G Datasheet

Current PartRFQ

MMBTA55LT1G

onsemiIn Stock: 125475MMBTA55LT1G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MPSA55G are selected based on strict electrical parameter equivalence. The following criteria determine substitution validity:

Electrical Equivalence Requirements:

• Transistor type must be PNP
• Maximum collector current (Ic) must be ≥ 500 mA
• Collector-emitter breakdown voltage must be ≥ 60 V
• Vce saturation characteristics must match at specified bias conditions
• DC current gain (hFE) minimum must be ≥ 100 at 100 mA, 1 V
• Transition frequency must be ≥ 50 MHz
• Operating temperature range must encompass -55°C to 150°C

Mechanical and Packaging Considerations: Substitute parts may differ in mounting technology (Through Hole versus Surface Mount) and package form factor, provided all electrical parameters remain equivalent or superior. Package differences require circuit board redesign and assembly process modification but do not affect electrical functionality when parameters are matched.

Compliance and Status: Active product status and current manufacturing availability are preferred for long-term supply chain stability. RoHS and REACH compliance status are documented where applicable.

Parameter Comparison

Engineering Selection Recommendations

The MMBTA55LT1G is electrically equivalent to the MPSA55G across all critical transistor parameters: collector current, breakdown voltage, saturation characteristics, current gain, and transition frequency. Both devices operate across the identical temperature range and are manufactured by onsemi.

Key Differentiation Factors:

Product Status: The MPSA55G is obsolete with limited inventory availability (5,100 pieces). The MMBTA55LT1G is active with substantial current production (125,400 pieces in stock), ensuring long-term supply chain continuity.

Compliance: The MMBTA55LT1G carries ROHS3 compliance certification, meeting current regulatory requirements for electronic component manufacturing and distribution.

Package and Mounting: The primary distinction is packaging technology. The MPSA55G uses Through Hole TO-92-3 mounting, while the MMBTA55LT1G uses Surface Mount SOT-23-3 packaging. This difference requires circuit board layout modification and assembly process changes but does not affect electrical performance.

Power Dissipation: The MMBTA55LT1G has a maximum power rating of 225 mW compared to the MPSA55G at 625 mW. For applications operating within the 225 mW thermal envelope, this presents no limitation. Applications requiring power dissipation above 225 mW must retain the MPSA55G or identify alternative solutions.

Frequently Asked Questions (FAQ)

Q: Can the MMBTA55LT1G directly replace the MPSA55G in existing circuit designs?

A: Electrical substitution is valid when all circuit parameters operate within the MMBTA55LT1G specifications. The primary constraint is power dissipation: if the application requires sustained power dissipation exceeding 225 mW, the MMBTA55LT1G cannot be used. Circuit board redesign is required due to package differences (Through Hole versus Surface Mount).

Q: What are the implications of the different package types?

A: The MPSA55G uses a Through Hole TO-92-3 package for insertion into plated through-hole circuit boards. The MMBTA55LT1G uses a Surface Mount SOT-23-3 package requiring surface mount assembly equipment and techniques. These are mechanically and electrically distinct mounting technologies requiring different board designs and manufacturing processes.

Q: Are there any electrical performance differences between these parts?

A: No. Both devices share identical electrical specifications for collector current, breakdown voltage, saturation voltage, current gain, transition frequency, and operating temperature range. The MMBTA55LT1G has lower maximum power dissipation (225 mW versus 625 mW), which may be a limiting factor in high-power applications.

Q: Why is the MPSA55G classified as obsolete?

A: The MPSA55G is no longer in active production by onsemi. The MMBTA55LT1G represents the active equivalent in the onsemi product portfolio, offering the same electrical functionality in a modern surface mount package.

Q: What compliance certifications apply to each part?

A: The MMBTA55LT1G carries ROHS3 compliance certification. The MPSA55G compliance status is not specified in available documentation. Both parts are REACH Unaffected and carry EAR99 export classification.

Q: Can the MMBTA55LT1G be used in applications with power dissipation between 225 mW and 625 mW?

A: No. The MMBTA55LT1G maximum power rating is 225 mW. Applications requiring sustained power dissipation above this threshold must use the MPSA55G or identify alternative components with higher power ratings.