RN4985FE,LF(CT Pre-Biased Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The RN4985FE,LF(CT is an active pre-biased dual bipolar transistor (BJT) manufactured by Toshiba Semiconductor and Storage. This surface mount component integrates one NPN and one PNP transistor with integrated base resistors in a compact ES6 package. The device is designed for applications requiring matched transistor pairs with predictable switching characteristics and is compliant with RoHS3 standards.

Identification of equivalent and substitute parts is necessary to address supply chain continuity, inventory optimization, and design flexibility while maintaining electrical and mechanical compatibility within specified parameters.

Substiute Parts

RN4985FE,LF(CT

Toshiba Semiconductor and StorageIn Stock: 1273RN4985FE,LF(CT Datasheet

Current PartRFQ

DCX123JH-7

Diodes IncorporatedIn Stock: 39129DCX123JH-7 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the RN4985FE,LF(CT is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Criteria:

• Transistor configuration: 1 NPN + 1 PNP pre-biased dual pair
• Maximum collector current: 100mA
• Collector-emitter breakdown voltage: 50V
• Integrated base resistor (R1): 2.2kOhms
• Integrated emitter-base resistor (R2): 47kOhms
• DC current gain (hFE): minimum 80 @ 10mA, 5V
• Saturation voltage: 300mV maximum @ 250µA, 5mA
• Collector cutoff current: 500nA maximum
• Transition frequency: 250MHz or 200MHz
• Maximum power dissipation: 100mW or greater

Mechanical Equivalence Criteria:

• Surface mount technology
• Package compatibility: SOT-563 or SOT-666
• Moisture sensitivity level: 1 (Unlimited)

Compliance Criteria:

• RoHS3 compliance required
• ECCN classification: EAR99

The DCX123JH-7 manufactured by Diodes Incorporated meets all electrical and mechanical equivalence criteria and is classified as a direct substitute for the RN4985FE,LF(CT.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: DCX123JH-7 (Diodes Incorporated)

The DCX123JH-7 is a direct electrical and mechanical equivalent to the RN4985FE,LF(CT. All critical parameters including collector current, breakdown voltage, integrated resistor values, current gain, saturation voltage, and cutoff current are identical. Both devices are RoHS3 compliant and feature MSL Level 1 (Unlimited) moisture sensitivity ratings.

The DCX123JH-7 provides enhanced power dissipation capability (150mW versus 100mW), which represents a performance advantage in thermal margin without introducing any compatibility constraints. The transition frequency specification of 250MHz in the DCX123JH-7 meets the primary frequency requirement of the RN4985FE,LF(CT.

Both devices are surface mount components in SOT-563 or SOT-666 packages, ensuring mechanical compatibility in existing PCB layouts. The ECCN classification (EAR99) and HTSUS codes are identical, confirming regulatory equivalence.

Selection between these parts should be based on availability, lead time, cost, and supply chain strategy rather than technical performance differences.

Frequently Asked Questions (FAQ)

Q: Can the DCX123JH-7 be used as a direct replacement for the RN4985FE,LF(CT in production?

A: Yes. The DCX123JH-7 meets all electrical specifications, integrated resistor values, and mechanical requirements. No circuit modifications are required. Both devices are RoHS3 compliant with identical moisture sensitivity levels.

Q: Are there package compatibility concerns when substituting the DCX123JH-7?

A: No. Both the RN4985FE,LF(CT and DCX123JH-7 are available in SOT-563 and SOT-666 packages. Pin configurations and footprints are identical, allowing direct PCB substitution without layout changes.

Q: What is the significance of the higher power rating (150mW) in the DCX123JH-7?

A: The DCX123JH-7 power rating of 150mW exceeds the RN4985FE,LF(CT specification of 100mW. This provides additional thermal margin and does not create any compatibility issues. The substitute part operates within the same electrical operating range as the original part.

Q: Do both parts have the same integrated resistor configuration?

A: Yes. Both the RN4985FE,LF(CT and DCX123JH-7 feature identical integrated base resistor (R1) of 2.2kOhms and emitter-base resistor (R2) of 47kOhms. This ensures equivalent biasing behavior in circuit applications.

Q: Are there any regulatory or compliance differences between these parts?

A: No. Both parts are RoHS3 compliant, carry EAR99 ECCN classification, and share identical HTSUS codes. Moisture sensitivity level is 1 (Unlimited) for both devices, indicating no special handling requirements.

Q: What transition frequency specifications apply to each part?

A: The RN4985FE,LF(CT specifies 250MHz and 200MHz transition frequencies. The DCX123JH-7 specifies 250MHz. The DCX123JH-7 meets the primary frequency requirement and is suitable for applications requiring 250MHz performance.

Q: Can these parts be intermixed in the same production batch?

A: Yes. Both parts are electrically and mechanically equivalent. Intermixing is permissible from a technical standpoint. Supply chain and quality control procedures should govern any decisions regarding mixed sourcing.