RN1403,LF Pre-Biased NPN Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The RN1403,LF is an active pre-biased NPN bipolar transistor (BJT) manufactured by Toshiba Semiconductor and Storage. This surface mount component operates at 50 V collector-emitter breakdown voltage with a maximum collector current of 100 mA and is housed in a TO-236-3 (SOT-23-3) package. The device is designed for applications requiring integrated base bias resistors, eliminating the need for external biasing networks in switching and amplification circuits.

Substitute parts are necessary when the primary part experiences supply constraints, extended lead times, or when design flexibility across multiple manufacturers is required. All substitute components listed maintain electrical and mechanical compatibility with the RN1403,LF within the specified parameter ranges.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN - Pre-Biased	—
Current - Collector (Ic) (Max)	100	mA
Voltage - Collector Emitter Breakdown (Max)	50	V
Resistor - Base (R1)	22	kOhms
Resistor - Emitter Base (R2)	22	kOhms
Frequency - Transition	250	MHz
Power - Max	200	mW
Mounting Type	Surface Mount	—
Package / Case	TO-236-3, SC-59, SOT-23-3	—
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level (MSL)	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution eligibility for the RN1403,LF is determined by strict adherence to the following electrical and mechanical parameters:

Critical Matching Parameters:

Transistor Type: NPN - Pre-Biased
Maximum Collector Current (Ic): 100 mA
Maximum Collector-Emitter Breakdown Voltage: 50 V
Base Resistor (R1): 22 kOhms
Emitter-Base Resistor (R2): 22 kOhms
Transition Frequency: 250 MHz (or equivalent)
Maximum Power Dissipation: 200 mW or greater
Package Type: TO-236-3, SC-59, or SOT-23-3 (surface mount)
RoHS Compliance: ROHS3 Compliant
Moisture Sensitivity Level: 1 (Unlimited)

All substitute parts listed below satisfy these criteria. Variations in secondary parameters such as DC current gain (hFE) at different measurement conditions, saturation voltage (Vce), and cutoff current are within acceptable engineering tolerances for pre-biased BJT applications and do not preclude substitution.

Parameter Comparison

Manufacturer Part Number	Manufacturer	Ic (Max) mA	Vce(br) (Max) V	R1 (Base) kOhms	R2 (Emitter-Base) kOhms	Frequency - Transition MHz	Power - Max mW	Package	RoHS Status
RN1403,LF	Toshiba Semiconductor and Storage	100	50	22	22	250	200	TO-236-3, SC-59, SOT-23-3	ROHS3 Compliant
DTC124ECAT116	Rohm Semiconductor	100	50	22	22	250	200	TO-236-3, SC-59, SOT-23-3	ROHS3 Compliant
NSVMMUN2212LT1G	onsemi	100	50	22	22	—	246	TO-236-3, SC-59, SOT-23-3	ROHS3 Compliant
NSVMUN2212T1G	onsemi	100	50	22	22	—	230	TO-236-3, SC-59, SOT-23-3	ROHS3 Compliant
PDTC124ET,215	Nexperia USA Inc.	100	50	22	22	—	250	TO-236-3, SC-59, SOT-23-3	ROHS3 Compliant
PDTC124ET,235	NXP USA Inc.	100	50	22	22	—	250	TO-236-3, SC-59, SOT-23-3	ROHS3 Compliant
SMUN2212T1G	onsemi	100	50	22	22	—	230	TO-236-3, SC-59, SOT-23-3	ROHS3 Compliant

Engineering Selection Recommendations

All substitute parts listed are active products with ROHS3 compliance and MSL Level 1 (Unlimited) moisture sensitivity ratings, matching the RN1403,LF specifications. Selection among these alternatives should be based on:

Availability and Lead Time: PDTC124ET,235 (NXP USA Inc.) maintains the highest inventory level at 60,735 pieces, followed by NSVMMUN2212LT1G (onsemi) at 95,300 pieces. These options provide optimal supply chain flexibility.

Packaging Considerations: All substitute parts are available in TO-236-3, SC-59, or SOT-23-3 surface mount packages. Verify the specific package designation required for your PCB assembly process, as some manufacturers designate the same physical package with different nomenclature (e.g., SST3 versus SOT-23-3).

Regulatory Compliance: All listed substitutes maintain ROHS3 compliance and REACH Unaffected status where specified, ensuring compatibility with environmental and regulatory requirements.

Power Dissipation: PDTC124ET,215 and PDTC124ET,235 offer maximum power ratings of 250 mW, providing additional thermal margin compared to the RN1403,LF at 200 mW. This characteristic is beneficial in applications approaching maximum power limits.

Frequently Asked Questions (FAQ)

Q: Can PDTC124ET,235 directly replace RN1403,LF without PCB modifications?

A: Yes. Both components share identical electrical specifications for collector current (100 mA), collector-emitter breakdown voltage (50 V), and integrated base and emitter-base resistors (22 kOhms each). Both are housed in TO-236-3 (SOT-23-3) surface mount packages with identical pin configurations. No PCB layout changes are required.

Q: What is the significance of the different package designations (SOT-23-3, SC-59, S-Mini, SST3)?

A: These designations refer to the same physical package form factor used by different manufacturers. SOT-23-3 and SC-59 are industry-standard designations for the three-pin surface mount package. S-Mini and SST3 are manufacturer-specific nomenclature for the identical package. All listed parts are mechanically and electrically compatible within this package family.

Q: Are there differences in DC current gain (hFE) between the RN1403,LF and substitute parts?

A: Yes. The RN1403,LF specifies hFE (Min) of 70 @ 10mA, 5V, while most substitutes specify hFE (Min) of 60 @ 5mA, 5V or 10V. These variations reflect different measurement conditions and manufacturer test protocols. Both specifications fall within acceptable ranges for pre-biased BJT applications where the integrated bias resistors establish predictable switching behavior independent of absolute hFE values.

Q: Which substitute part offers the best thermal performance?

A: PDTC124ET,215 and PDTC124ET,235 both specify maximum power dissipation of 250 mW, compared to 200 mW for the RN1403,LF. This 25% increase in power rating provides additional thermal margin in applications operating near maximum power limits.

Q: Is the RN1403,LF still in active production?

A: Yes. The RN1403,LF maintains Active product status with 3,848 pieces in current inventory. All listed substitute parts also maintain Active status, ensuring long-term availability and continued manufacturer support.

Q: Can I use NSVMMUN2212LT1G as a substitute if my design requires 250 MHz transition frequency?

A: The NSVMMUN2212LT1G does not specify transition frequency in the provided data. However, this component is electrically and mechanically compatible with the RN1403,LF across all other critical parameters. If transition frequency specification is mandatory for your application, PDTC124ET,215 or PDTC124ET,235 are recommended as they maintain the 250 MHz specification.

Q: What is the difference between Cut Tape (CT) and Tape & Reel (TR) packaging formats?

A: Cut Tape (CT) and Digi-Reel® packaging are supplied in smaller quantities suitable for manual assembly or low-volume production. Tape & Reel (TR) packaging is supplied on continuous reels for automated pick-and-place assembly equipment. Both formats contain identical components; selection depends on your assembly process requirements and volume.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message