RN1111,LF(CT Pre-Biased NPN Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The RN1111,LF(CT is a pre-biased NPN bipolar transistor manufactured by Toshiba Semiconductor and Storage, designed for surface mount applications in the SC-75 (SOT-416) package. This active product operates at 50 V collector-emitter breakdown voltage with a maximum collector current of 100 mA and transition frequency of 250 MHz. The device integrates a 10 kOhm base resistor and is rated for 100 mW maximum power dissipation.

Equivalent and substitute parts are necessary when the primary part number becomes unavailable, when alternative packaging formats are required for manufacturing processes, or when design modifications necessitate different internal resistor values while maintaining core electrical performance parameters.

Substiute Parts

RN1111,LF(CT

Toshiba Semiconductor and StorageIn Stock: 764RN1111,LF(CT Datasheet

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DDTC114GE-7-F

Diodes IncorporatedIn Stock: 39136DDTC114GE-7-F Datasheet

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DDTC124GE-7-F

Diodes IncorporatedIn Stock: 842DDTC124GE-7-F Datasheet

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DDTC144GE-7-F

Diodes IncorporatedIn Stock: 738DDTC144GE-7-F Datasheet

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DTC114TET1G

onsemiIn Stock: 8001DTC114TET1G Datasheet

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DTC114TETL

Rohm SemiconductorIn Stock: 140531DTC114TETL Datasheet

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DTC143TETL

Rohm SemiconductorIn Stock: 29422DTC143TETL Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the RN1111,LF(CT is determined by strict adherence to the following electrical and mechanical parameters:

Core Substitution Criteria:

• Transistor Type: NPN - Pre-Biased
• Voltage - Collector Emitter Breakdown (Max): 50 V
• Current - Collector (Ic) (Max): 100 mA
• Frequency - Transition: 250 MHz
• Mounting Type: Surface Mount
• RoHS Compliance Status: Active product status

Secondary Considerations:

• Internal base or emitter resistor values (R1 or R2)
• DC Current Gain (hFE) specifications
• Vce Saturation characteristics
• Package format (SC-75/SOT-416 or SOT-523)
• Power dissipation rating

Substitute parts are grouped into two categories based on package compatibility:

Category 1: SC-75/SOT-416 Package (Direct Mechanical Compatibility)

• DTC114TET1G (onsemi)
• DTC114TETL (Rohm Semiconductor)
• DTC143TETL (Rohm Semiconductor)

Category 2: SOT-523 Package (Alternative Packaging)

• DDTC114GE-7-F (Diodes Incorporated)
• DDTC124GE-7-F (Diodes Incorporated)
• DDTC144GE-7-F (Diodes Incorporated)

All listed substitutes maintain the core electrical specifications of 50 V breakdown voltage, 100 mA maximum collector current, and 250 MHz transition frequency. Variations in internal resistor values and power ratings are documented in the parameter comparison table.

Parameter Comparison

Engineering Selection Recommendations

SC-75/SOT-416 Package Substitutes (Direct Footprint Compatibility):

The DTC114TET1G (onsemi), DTC114TETL (Rohm Semiconductor), and DTC143TETL (Rohm Semiconductor) are mechanically compatible with the RN1111,LF(CT in SC-75/SOT-416 package format. All three maintain active product status and ROHS3 compliance. The DTC114 variants (both onsemi and Rohm) feature identical 10 kOhm base resistor values to the RN1111,LF(CT. The DTC143TETL incorporates a 4.7 kOhm base resistor, resulting in different DC current gain and saturation characteristics suitable for applications requiring lower base resistance.

SOT-523 Package Substitutes (Alternative Packaging):

The DDTC114GE-7-F, DDTC124GE-7-F, and DDTC144GE-7-F (Diodes Incorporated) provide electrical equivalence with alternative SOT-523 packaging. These devices employ emitter-base resistor (R2) configuration rather than base resistor (R1) configuration. The DDTC114GE-7-F maintains 10 kOhm emitter-base resistance equivalent to the RN1111,LF(CT base resistance. The DDTC124GE-7-F and DDTC144GE-7-F feature 22 kOhm and 47 kOhm emitter-base resistances respectively, providing alternative biasing characteristics for specific circuit requirements.

Compliance and Availability:

All substitute parts maintain RoHS compliance and MSL Level 1 (Unlimited) moisture sensitivity rating. Product status is active for all listed alternatives, ensuring long-term availability. Selection between SC-75/SOT-416 and SOT-523 packages depends on PCB layout requirements and manufacturing process compatibility.

Frequently Asked Questions (FAQ)

Q: Can the RN1111,LF(CT be directly replaced with a SOT-523 package substitute?

A: Direct replacement requires PCB layout modification. The RN1111,LF(CT uses SC-75/SOT-416 package, while DDTC series substitutes use SOT-523 package. Footprints are not mechanically compatible. PCB redesign is necessary for SOT-523 substitution.

Q: What is the difference between base resistor (R1) and emitter-base resistor (R2) configuration?

A: The RN1111,LF(CT and DTC114 variants integrate a base resistor (R1) between base and collector. The DDTC series integrates an emitter-base resistor (R2) between emitter and base. This configuration difference affects biasing behavior and DC current gain characteristics. Circuit performance impact depends on specific application requirements.

Q: Are all listed substitutes suitable for 250 MHz operation?

A: The DTC114TET1G (onsemi) specifies 200 MHz transition frequency, which is lower than the RN1111,LF(CT 250 MHz specification. All other substitutes maintain 250 MHz transition frequency. Application requirements determine whether 200 MHz operation is acceptable.

Q: What is the significance of different internal resistor values in DDTC substitutes?

A: The DDTC114GE-7-F (10 kOhms), DDTC124GE-7-F (22 kOhms), and DDTC144GE-7-F (47 kOhms) provide different DC current gain characteristics. Higher emitter-base resistance results in lower DC current gain. Selection depends on circuit biasing requirements and desired switching characteristics.

Q: Can the RN1111,LF(CT be substituted with DTC143TETL?

A: The DTC143TETL maintains SC-75/SOT-416 package compatibility and core electrical specifications (50 V, 100 mA, 250 MHz). However, the 4.7 kOhm base resistor differs from the RN1111,LF(CT 10 kOhm base resistor, resulting in different DC current gain and saturation voltage characteristics. Substitution is valid only if circuit design accommodates these parameter variations.

Q: What inventory considerations apply to these substitutes?

A: Inventory availability varies significantly. DTC114TETL (Rohm) shows 140,518 pieces in stock, while DDTC124GE-7-F (Diodes) shows 740 pieces. Availability should be verified at time of procurement to ensure supply chain continuity.

Q: Are all substitutes RoHS3 compliant?

A: The RN1111,LF(CT is RoHS Compliant. All listed substitutes are ROHS3 Compliant, which represents a more recent compliance standard. ROHS3 compliance is backward compatible with RoHS requirements.