2N3903 Equivalent & Substitute Parts

Part Overview

The 2N3903 is an NPN bipolar junction transistor (BJT) manufactured by onsemi, rated for 40 V collector-emitter breakdown voltage and 200 mA maximum collector current in a Through Hole TO-92-3 package. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The 2N3903 serves general-purpose switching and amplification applications in low-power circuits requiring moderate voltage and current ratings.

Substiute Parts

2N3903

onsemiIn Stock: 12322N3903 Datasheet

Current PartRFQ

2N3904-AP

Micro Commercial CoIn Stock: 23902N3904-AP Datasheet

SimilarRFQ

2N4401-AP

Micro Commercial CoIn Stock: 154062N4401-AP Datasheet

SimilarRFQ

MPSA06-AP

Micro Commercial CoIn Stock: 64435MPSA06-AP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2N3903 is determined by electrical and mechanical compatibility within the following criteria:

Primary Substitution Criteria:

• Transistor Type: NPN (required match)
• Voltage - Collector Emitter Breakdown (Max): ≥ 40 V
• Current - Collector (Ic) Max: ≥ 200 mA
• Power - Max: ≥ 625 mW
• Mounting Type: Through Hole (required match)
• Package / Case: TO-92-3 or TO-226-3 compatible (required match)
• Operating Temperature Range: Must encompass or exceed -55°C to 150°C

Secondary Compatibility Factors:

• DC Current Gain (hFE): Minimum 50 @ 10 mA, 1 V (or higher)
• Vce Saturation: Lower values indicate improved performance

Substitute parts listed below meet or exceed the 2N3903 electrical specifications while maintaining identical mechanical form factor and mounting compatibility.

Parameter Comparison

Engineering Selection Recommendations

2N3904-AP (Micro Commercial Co)

The 2N3904-AP is a direct electrical equivalent to the 2N3903, matching the 40 V breakdown voltage and 200 mA collector current specifications. It provides superior DC current gain (100 vs. 50 minimum) and includes transition frequency specification (250 MHz). The 2N3904-AP is ROHS3 compliant and maintains identical TO-92-3 package compatibility. This substitute is suitable for applications where the original 2N3903 specifications are fully met or where improved gain characteristics are beneficial.

2N4401-AP (Micro Commercial Co)

The 2N4401-AP maintains 40 V breakdown voltage and TO-92-3 package compatibility but supports higher collector current (500 mA vs. 200 mA) and provides 250 MHz transition frequency. This substitute is applicable in designs requiring higher current capacity while operating within the same voltage envelope. The higher Vce saturation (750 mV) may impact switching performance in saturation-mode applications.

MPSA06-AP (Micro Commercial Co)

The MPSA06-AP offers enhanced voltage rating (80 V vs. 40 V) and current capacity (500 mA vs. 200 mA) in the same TO-92-3 package. This substitute is suitable for applications requiring higher voltage headroom or increased current handling. The lower Vce saturation (250 mV) provides improved switching efficiency. All substitute parts maintain the -55°C to 150°C operating temperature range and Through Hole mounting compatibility.

Frequently Asked Questions (FAQ)

Q: Can the 2N3904-AP directly replace the 2N3903 in all applications?

A: The 2N3904-AP meets or exceeds all electrical specifications of the 2N3903 (40 V breakdown, 200 mA collector current, 625 mW power dissipation) and shares identical TO-92-3 package geometry. Direct substitution is valid for applications operating within the 2N3903 design envelope. The higher DC current gain (100 vs. 50) may alter circuit biasing in designs relying on specific gain characteristics.

Q: What is the difference between 2N3904-AP and 2N4401-AP?

A: Both devices share 40 V breakdown voltage and TO-92-3 packaging. The 2N4401-AP supports higher collector current (500 mA vs. 200 mA) and exhibits higher Vce saturation (750 mV vs. 400 mV). Selection depends on circuit current requirements and saturation-mode performance tolerance.

Q: When should MPSA06-AP be selected over 2N3904-AP?

A: The MPSA06-AP provides doubled voltage rating (80 V vs. 40 V) and higher current capacity (500 mA vs. 200 mA). Selection of MPSA06-AP is appropriate for circuits requiring higher voltage margins or increased current handling. The lower Vce saturation (250 mV) improves switching efficiency in saturation applications.

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

A: All listed substitute parts (2N3904-AP, 2N4401-AP, MPSA06-AP) are available in TO-92-3 (TO-226AA) Through Hole package with formed leads, ensuring mechanical and pin compatibility with the 2N3903.

Q: What is the operating temperature range for substitute parts?

A: All substitute parts maintain the -55°C to 150°C (TJ) operating temperature range, matching the 2N3903 specification.

Q: Are substitute parts RoHS compliant?

A: The 2N3904-AP, 2N4401-AP, and MPSA06-AP are all ROHS3 compliant. The original 2N3903 RoHS status is not specified in available documentation.

Q: How do DC current gain differences affect circuit design?

A: The 2N3903 specifies minimum DC current gain (hFE) of 50 @ 10 mA, 1 V. All substitute parts provide minimum hFE of 100 at their respective test conditions, resulting in higher gain. Circuits designed with specific bias resistor values may require recalculation to maintain intended operating points.