PEMF21,115 Pre-Biased Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The PEMF21,115 is a pre-biased bipolar transistor (BJT) manufactured by Nexperia USA Inc., combining one NPN pre-biased transistor and one PNP transistor in a single surface mount package. This dual-transistor configuration operates at maximum collector currents of 100mA (NPN) and 500mA (PNP), with collector-emitter breakdown voltages of 50V and 12V respectively. The device is rated for 300mW maximum power dissipation and features a transition frequency of 280MHz.

The PEMF21,115 is classified as obsolete. Locating equivalent substitute parts is necessary to support ongoing maintenance, repair, and redesign activities for legacy systems utilizing this component.

Substiute Parts

PEMF21,115

Nexperia USA Inc.In Stock: 1060PEMF21,115 Datasheet

Current PartRFQ

EMF5XV6T5G

onsemiIn Stock: 17375EMF5XV6T5G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PEMF21,115 is determined by strict equivalence across the following electrical and mechanical parameters:

Critical Matching Parameters:

• Transistor configuration (1 NPN pre-biased + 1 PNP)
• Maximum collector currents (100mA NPN, 500mA PNP)
• Collector-emitter breakdown voltages (50V NPN, 12V PNP)
• Surface mount packaging compatibility
• RoHS3 compliance and MSL rating

Allowable Variations:

• Internal base and emitter-base resistor values (pre-bias network design differences)
• DC current gain (hFE) specifications
• Saturation voltage characteristics
• Maximum power dissipation (equal or greater)
• Package case designation (SOT-563 or SOT-666 footprint compatibility)

The EMF5XV6T5G manufactured by onsemi meets the core electrical requirements and compliance standards, making it a valid substitute despite differences in internal resistor networks and power rating.

Parameter Comparison

Engineering Selection Recommendations

Substitution Feasibility:

The EMF5XV6T5G is a valid electrical substitute for the PEMF21,115 based on matching core specifications: identical transistor configuration, collector current ratings, and breakdown voltages. Both devices maintain ROHS3 compliance and MSL Level 1 ratings, ensuring compatibility with standard manufacturing and storage protocols.

Design Considerations:

The primary difference between these devices lies in the internal pre-bias resistor networks. The PEMF21,115 incorporates 10kOhm base and emitter-base resistors, while the EMF5XV6T5G uses 47kOhm resistors. This difference affects the bias point and switching characteristics of the pre-biased transistor pair. Circuit performance may vary depending on application-specific load conditions and signal levels.

The EMF5XV6T5G provides a higher maximum power dissipation rating (500mW versus 300mW), offering improved thermal margin in power-constrained applications.

Compliance Status:

Both devices are classified as obsolete. Selection between these parts should prioritize availability and inventory status. The EMF5XV6T5G currently maintains significantly higher stock levels (17,300 pieces versus 975 pieces for the PEMF21,115).

Frequently Asked Questions (FAQ)

Q: Can the EMF5XV6T5G directly replace the PEMF21,115 in existing designs?

A: Electrical substitution is valid based on matching collector currents, breakdown voltages, and transistor configuration. However, the different internal resistor values (47kOhm versus 10kOhm) will alter the pre-bias network behavior. Circuit simulation or bench testing is appropriate to confirm performance in specific applications.

Q: What is the significance of the different base resistor values?

A: The base resistor (R1) and emitter-base resistor (R2) form the pre-bias network that establishes the quiescent operating point of the transistor pair. Higher resistor values in the EMF5XV6T5G result in lower bias currents compared to the PEMF21,115. This affects switching speed, saturation characteristics, and overall circuit gain.

Q: Are both devices available in the same package options?

A: Yes. Both the PEMF21,115 and EMF5XV6T5G are available in SOT-563 and SOT-666 package cases. Verify the specific supplier device package for your application to ensure footprint compatibility.

Q: Do both parts meet current environmental and compliance standards?

A: Yes. Both devices are ROHS3 compliant and carry MSL Level 1 (Unlimited) moisture sensitivity ratings, meeting standard manufacturing and storage requirements.

Q: Why is the EMF5XV6T5G rated for higher power dissipation?

A: The 500mW rating of the EMF5XV6T5G versus the 300mW rating of the PEMF21,115 reflects differences in die design and thermal characteristics between manufacturers. The higher rating provides additional thermal margin but does not change the electrical operating parameters.

Q: What should be considered when selecting between these obsolete parts?

A: Prioritize availability and lead time. The EMF5XV6T5G has substantially higher inventory levels. Evaluate circuit sensitivity to pre-bias resistor network differences through simulation or prototype testing before committing to production quantities.