RN1903,LF(CT Pre-Biased Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The RN1903,LF(CT is a pre-biased dual NPN bipolar transistor manufactured by Toshiba Semiconductor and Storage. This surface mount component operates at 50V maximum collector-emitter breakdown voltage with a maximum collector current of 100mA and 200mW power dissipation. The device features integrated base and emitter-base resistors (22kOhms each) and operates at 250MHz transition frequency. The RN1903,LF(CT is actively produced and RoHS3 compliant with unlimited moisture sensitivity rating (MSL 1). Equivalent and substitute parts are necessary when the primary part experiences supply constraints, extended lead times, or when design requirements permit functional alternatives that meet the same electrical and mechanical specifications.

Key Parameters

Parameter	Value	Unit
Transistor Type	2 NPN - Pre-Biased (Dual)	—
Collector Current (Ic) Maximum	100	mA
Collector-Emitter Breakdown Voltage (Max)	50	V
Base Resistor (R1)	22	kOhms
Emitter-Base Resistor (R2)	22	kOhms
DC Current Gain (hFE) Minimum	70	@ 10mA, 5V
Vce Saturation Maximum	300	mV @ 250µA, 5mA
Collector Cutoff Current (ICBO)	100	nA
Transition Frequency	250	MHz
Power Dissipation Maximum	200	mW
Package Type	6-TSSOP, SC-88, SOT-363	—
Mounting Type	Surface Mount	—
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution of the RN1903,LF(CT is determined by strict equivalence across the following critical parameters:

Primary Substitution Criteria:

Transistor configuration: 2 NPN pre-biased dual or 1 NPN + 1 PNP pre-biased dual
Maximum collector current: 100mA
Maximum collector-emitter breakdown voltage: 50V
Base resistor value: 22kOhms
Emitter-base resistor value: 22kOhms (or 47kOhms for PUMD16,115)
Transition frequency: 250MHz or higher
Power dissipation: 200mW or greater
Package compatibility: 6-TSSOP, SC-88, or SOT-363
Surface mount configuration
RoHS3 compliance
MSL rating: 1 (Unlimited)

Secondary Considerations:

DC current gain (hFE) minimum specifications vary across substitutes
Vce saturation characteristics differ between manufacturers
Collector cutoff current (ICBO) ranges from 100nA to 1µA
Automotive qualification (AEC-Q100 or AEC-Q101) available for specific substitutes

Substitutes are grouped into two categories: direct functional equivalents with identical transistor configuration (2 NPN) and compatible alternatives with mixed configuration (1 NPN + 1 PNP) that maintain electrical performance within the specified parameter ranges.

Parameter Comparison

Parameter	RN1903,LF(CT	DCX124EU-7-F	DCX124EUQ-7-F	MUN5212DW1T1G	NSVMUN5212DW1T1G	PUMD16,115	PUMD2,115	PUMD2,125	PUMD2,165	PUMH1,115	UMH1NFHATN
Manufacturer	Toshiba	Diodes Inc.	Diodes Inc.	onsemi	onsemi	Nexperia	Nexperia	Nexperia	Nexperia	Nexperia	Rohm
Transistor Type	2 NPN	1 NPN, 1 PNP	1 NPN, 1 PNP	2 NPN	2 NPN	1 NPN, 1 PNP	1 NPN, 1 PNP	1 NPN, 1 PNP	1 NPN, 1 PNP	2 NPN	2 NPN
Ic (Max) [mA]	100	100	100	100	100	100	100	100	100	100	100
Vce Breakdown (Max) [V]	50	50	50	50	50	50	50	50	50	50	50
R1 Base [kOhms]	22	22	22	22	22	22	22	22	22	22	22
R2 Emitter-Base [kOhms]	22	22	22	22	22	47	22	22	22	22	22
hFE (Min) @ Ic, Vce	70 @ 10mA, 5V	56 @ 5mA, 5V	100 @ 1mA, 5V	60 @ 5mA, 10V	60 @ 5mA, 10V	80 @ 5mA, 5V	60 @ 5mA, 5V	60 @ 5mA, 5V	60 @ 5mA, 5V	60 @ 5mA, 5V	56 @ 5mA, 5V
Vce Saturation (Max) [mV]	300 @ 250µA, 5mA	300 @ 500µA, 10mA	Not specified	250 @ 300µA, 10mA	250 @ 300µA, 10mA	150 @ 500µA, 10mA	150 @ 500µA, 10mA	150 @ 500µA, 10mA	150 @ 500µA, 10mA	150 @ 500µA, 10mA	300 @ 500µA, 10mA
ICBO (Max) [nA]	100	500	500	500	500	1000	1000	1000	1000	100	500
Frequency - Transition [MHz]	250	250	250	Not specified	Not specified	Not specified	Not specified	Not specified	Not specified	230	250
Power (Max) [mW]	200	200	200	250	250	300	300	300	300	300	150
Package	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363	6-TSSOP, SC-88, SOT-363
Mounting Type	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
MSL Rating	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)
Product Status	Active	Active	Active	Active	Active	Active	Active	Active	Active	Active	Active
Automotive Grade	No	No	Yes (AEC-Q101)	No	No	Yes (AEC-Q100)	No	No	No	No	Yes (AEC-Q101)

Engineering Selection Recommendations

Direct Configuration Equivalents (2 NPN Pre-Biased Dual):

The MUN5212DW1T1G and NSVMUN5212DW1T1G from onsemi provide direct transistor configuration equivalence to the RN1903,LF(CT. Both devices maintain identical collector current (100mA), breakdown voltage (50V), base and emitter-base resistor values (22kOhms each), and transition frequency (250MHz). These parts offer increased power dissipation (250mW versus 200mW) and are actively produced with RoHS3 compliance and MSL 1 rating. The NSVMUN5212DW1T1G variant provides higher inventory availability (35,100 units) compared to MUN5212DW1T1G (96,900 units).

The PUMH1,115 from Nexperia maintains the 2 NPN configuration with identical electrical parameters except for transition frequency (230MHz versus 250MHz) and higher power dissipation (300mW). This part is actively produced with RoHS3 compliance and MSL 1 rating.

The UMH1NFHATN from Rohm Semiconductor provides 2 NPN configuration with automotive qualification (AEC-Q101) and identical transition frequency (250MHz). This device features lower power dissipation (150mW) and is actively produced with RoHS3 compliance and MSL 1 rating.

Mixed Configuration Alternatives (1 NPN + 1 PNP Pre-Biased Dual):

The DCX124EU-7-F and DCX124EUQ-7-F from Diodes Incorporated provide mixed transistor configuration (1 NPN + 1 PNP) with identical electrical specifications for collector current (100mA), breakdown voltage (50V), base and emitter-base resistors (22kOhms each), and transition frequency (250MHz). The DCX124EUQ-7-F variant includes automotive qualification (AEC-Q101). Both devices are actively produced with RoHS3 compliance and MSL 1 rating.

The PUMD16,115 from Nexperia provides mixed configuration with automotive qualification (AEC-Q100), higher power dissipation (300mW), and improved saturation characteristics (150mV). The emitter-base resistor differs at 47kOhms. This part is actively produced with RoHS3 compliance and MSL 1 rating.

The PUMD2,115, PUMD2,125, and PUMD2,165 from Nexperia provide mixed configuration with identical electrical parameters, higher power dissipation (300mW), and improved saturation characteristics (150mV). These variants differ in packaging (Cut Tape versus Tape & Reel) and inventory levels. All are actively produced with RoHS3 compliance and MSL 1 rating.

Selection Basis:

All substitute parts maintain active product status and RoHS3 compliance. Selection between direct 2 NPN equivalents and mixed 1 NPN + 1 PNP alternatives depends on circuit design requirements. Automotive-qualified variants (DCX124EUQ-7-F, PUMD16,115, UMH1NFHATN) are available for applications requiring AEC-Q100 or AEC-Q101 certification. Higher power dissipation ratings (250mW to 300mW) in substitute parts provide design margin over the 200mW specification of the RN1903,LF(CT.

Frequently Asked Questions (FAQ)

Q: Can the DCX124EU-7-F replace the RN1903,LF(CT in all applications?

A: The DCX124EU-7-F maintains electrical equivalence across all critical parameters: 100mA collector current, 50V breakdown voltage, 22kOhms base and emitter-base resistors, and 250MHz transition frequency. The primary difference is transistor configuration (1 NPN + 1 PNP versus 2 NPN). Substitution is valid when circuit design accommodates the mixed configuration. Both devices are RoHS3 compliant with MSL 1 rating and active product status.

Q: What is the difference between MUN5212DW1T1G and NSVMUN5212DW1T1G?

A: Both devices provide identical electrical specifications and 2 NPN configuration matching the RN1903,LF(CT. The NSVMUN5212DW1T1G is a variant designation from onsemi with higher inventory availability (35,100 units versus 96,900 units for MUN5212DW1T1G). Both are actively produced with RoHS3 compliance and MSL 1 rating.

Q: Are automotive-qualified substitutes available?

A: Yes. The DCX124EUQ-7-F (Diodes Incorporated, AEC-Q101), PUMD16,115 (Nexperia, AEC-Q100), and UMH1NFHATN (Rohm Semiconductor, AEC-Q101) provide automotive qualification. These parts maintain electrical equivalence to the RN1903,LF(CT and are actively produced with RoHS3 compliance.

Q: Why do some substitutes have higher power dissipation ratings?

A: Substitute parts from onsemi (250mW) and Nexperia (300mW) provide higher power dissipation ratings than the RN1903,LF(CT (200mW). This difference reflects design margin and thermal performance characteristics of each manufacturer's process technology. The higher ratings do not affect substitution validity when the application operates within the 200mW specification of the original part.

Q: What is the significance of the emitter-base resistor difference in PUMD16,115?

A: The PUMD16,115 specifies 47kOhms for the emitter-base resistor (R2) compared to 22kOhms in the RN1903,LF(CT and most other substitutes. This parameter affects base current distribution and switching characteristics. Substitution with PUMD16,115 is valid when circuit design accommodates this resistor value difference or when the application tolerates the resulting bias network changes.

Q: Are all substitute parts available in the same package?

A: Yes. All substitute parts are available in 6-TSSOP, SC-88, or SOT-363 package configurations, matching the RN1903,LF(CT. All devices are surface mount components with identical pin configurations within the SOT-363 family.

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

A: Cut Tape (CT) and Digi-Reel® packaging is supplied in individual cut strips suitable for manual assembly or small-volume production. Tape & Reel (TR) packaging is supplied on continuous reels for automated assembly equipment. The RN1903,LF(CT is supplied in Cut Tape packaging. Substitute parts are available in both packaging formats depending on manufacturer and variant designation. Electrical specifications remain identical regardless of packaging format.

Q: Can the UMH1NFHATN be used as a direct replacement despite lower power dissipation?

A: The UMH1NFHATN provides 150mW power dissipation compared to the RN1903,LF(CT specification of 200mW. Substitution is valid when the application operates within the 150mW thermal budget. The device maintains identical collector current (100mA), breakdown voltage (50V), resistor values (22kOhms each), and transition frequency (250MHz). Automotive qualification (AEC-Q101) is an additional benefit for qualified applications.

Q: What parameters must remain identical for substitution to be valid?

A: Critical parameters that must remain identical or equivalent are: maximum collector current (100mA), collector-emitter breakdown voltage (50V), base resistor value (22kOhms), emitter-base resistor value (22kOhms or 47kOhms for PUMD16,115), transition frequency (250MHz or higher), package type (6-TSSOP/SC-88/SOT-363), surface mount configuration, RoHS3 compliance, and MSL 1 rating. Transistor configuration (2 NPN or 1 NPN + 1 PNP) may differ when circuit design permits.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message