RN1704,LF Pre-Biased Dual NPN Transistor Equivalent & Substitute Parts

Part Overview

The RN1704,LF is an active pre-biased dual NPN bipolar junction transistor (BJT) manufactured by Toshiba Semiconductor and Storage. This surface mount component integrates two NPN transistors with internal base and emitter-base resistors (47kOhms each) in a single 5-TSSOP package. The device operates at maximum ratings of 50V collector-emitter breakdown voltage, 100mA collector current, and 200mW power dissipation with a transition frequency of 250MHz.

Substitute parts become necessary when the primary part experiences supply discontinuation, extended lead times, inventory constraints, or when design flexibility requires alternative qualified sources. The RN1704,LF remains in active production status; however, equivalent alternatives meeting identical electrical and mechanical specifications are available from other manufacturers.

Substiute Parts

RN1704,LF

Toshiba Semiconductor and StorageIn Stock: 1275RN1704,LF Datasheet

Current PartRFQ

UMG2NTR

Rohm SemiconductorIn Stock: 98668UMG2NTR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the RN1704,LF is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• Transistor configuration: 2 NPN - Pre-Biased (Dual)
• Maximum collector current: 100mA
• Maximum collector-emitter breakdown voltage: 50V
• Internal base resistor (R1): 47kOhms
• Internal emitter-base resistor (R2): 47kOhms
• Transition frequency: 250MHz
• Package type: 5-TSSOP / SC-70-5 / SOT-353
• Mounting technology: Surface Mount

The UMG2NTR from Rohm Semiconductor meets all mandatory matching parameters. While the maximum power rating differs (150mW versus 200mW), this represents a derating condition that does not prevent functional substitution in applications operating within the lower power envelope. The DC current gain specification differs at different test conditions but remains within acceptable pre-biased transistor performance ranges.

Parameter Comparison

Engineering Selection Recommendations

RN1704,LF (Primary Selection)

The RN1704,LF from Toshiba Semiconductor and Storage is the primary component specification. This part maintains active production status, ROHS3 compliance, and unlimited moisture sensitivity rating (MSL 1). The 200mW power rating provides maximum thermal headroom for applications requiring full current and voltage envelope operation.

UMG2NTR (Qualified Substitute)

The UMG2NTR from Rohm Semiconductor is a qualified substitute for applications where the 150mW power rating is sufficient. This part is also in active production, ROHS3 compliant, and carries MSL 1 rating. The substitute is suitable for designs operating within the lower power envelope and where Rohm semiconductor sourcing is preferred or required.

Both parts are functionally interchangeable at the circuit level when power dissipation remains below 150mW. Selection between these parts should be based on supply chain requirements, inventory availability, and application power budget constraints.

Frequently Asked Questions (FAQ)

Q: Can the UMG2NTR replace the RN1704,LF in all applications?

A: The UMG2NTR is a functional substitute provided that circuit power dissipation does not exceed 150mW. Applications operating at the full 200mW specification of the RN1704,LF require the primary part or equivalent devices with matching 200mW ratings.

Q: Are the package dimensions identical between RN1704,LF and UMG2NTR?

A: Both parts use the 5-TSSOP / SC-70-5 / SOT-353 package type. Pin configuration and footprint are identical, enabling direct PCB layout compatibility without redesign.

Q: What is the significance of the internal resistor values (47kOhms R1 and R2)?

A: The internal base and emitter-base resistors define the pre-biasing network and switching characteristics of the dual transistor pair. Substitutes must maintain these exact values to preserve circuit behavior and switching performance.

Q: Do both parts meet the same environmental and compliance standards?

A: Yes. Both the RN1704,LF and UMG2NTR are ROHS3 compliant, carry MSL 1 (unlimited moisture sensitivity), and are classified under ECCN EAR99 for export control purposes.

Q: What is the primary difference between these two parts?

A: The maximum power dissipation rating differs: RN1704,LF is rated at 200mW while UMG2NTR is rated at 150mW. All other electrical and mechanical specifications are identical.

Q: Are there any DC current gain differences that affect circuit design?

A: The DC current gain (hFE) is specified at different test conditions for each part. The RN1704,LF specifies hFE minimum of 80 @ 10mA, 5V, while UMG2NTR specifies hFE minimum of 68 @ 5mA, 5V. Both values are within acceptable ranges for pre-biased transistor applications and do not require circuit redesign.