BC337 NPN Bipolar Junction Transistor Equivalent & Substitute Parts

Part Overview

The BC337 is an NPN bipolar junction transistor manufactured by onsemi, designed for general-purpose switching and amplification applications. The device features a maximum collector current of 800 mA, collector-emitter breakdown voltage of 45 V, and maximum power dissipation of 625 mW in a Through Hole TO-92-3 package. The BC337 is classified as obsolete, necessitating identification of active equivalent and substitute parts for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility within the specified parameter ranges while meeting current product availability and compliance standards.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN	—
Current - Collector (Ic) (Max)	800	mA
Voltage - Collector Emitter Breakdown (Max)	45	V
Vce Saturation (Max) @ Ib, Ic	700 mV @ 50 mA, 500 mA	—
DC Current Gain (hFE) (Min) @ Ic, Vce	100 @ 100 mA, 1 V	—
Power - Max	625	mW
Frequency - Transition	210	MHz
Operating Temperature Range	-55 to 150	°C (TJ)
Mounting Type	Through Hole	—
Package / Case	TO-92-3	—

Substitute Part Grouping Explanation

Substitution of the BC337 is determined by electrical parameter compatibility within the following criteria:

Primary Substitution Criteria:

Transistor Type: NPN configuration required
Collector Current (Ic): Minimum 800 mA to maintain current-handling capability
Collector-Emitter Breakdown Voltage (Vce(BR)CEO): Minimum 45 V to ensure voltage rating compatibility
Power Dissipation: Minimum 625 mW to support thermal requirements
DC Current Gain (hFE): Minimum 100 at specified operating points
Package Type: Through Hole TO-92-3 or compatible form factor
Operating Temperature Range: Support for -55°C to 150°C minimum

Substitution Categories:

Direct Substitutes maintain all primary electrical parameters and package specifications, enabling pin-for-pin replacement without circuit modification.

Compatible Substitutes meet or exceed all critical electrical parameters but may have minor variations in secondary characteristics such as transition frequency or saturation voltage, provided these variations do not degrade circuit performance.

Functional Alternatives satisfy the core electrical requirements but may operate in different package styles or have extended parameter ranges, requiring verification of mechanical fit and thermal management.

Parameter Comparison

Parameter	BC337 (onsemi)	2N4401BU (onsemi)	BC33716BU (Fairchild)	BC337-AP (MCC)	ZTX450 (Diodes Inc.)
Transistor Type	NPN	NPN	NPN	NPN	NPN
Ic (Max) [mA]	800	600	800	800	1000
Vce(BR)CEO (Max) [V]	45	40	45	45	45
Vce Saturation (Max) [mV]	700 @ 50 mA, 500 mA	750 @ 50 mA, 500 mA	700 @ 50 mA, 500 mA	700 @ 50 mA, 500 mA	250 @ 15 mA, 150 mA
hFE (Min) @ Ic, Vce	100 @ 100 mA, 1 V	100 @ 150 mA, 1 V	100 @ 100 mA, 1 V	60 @ 300 mA, 1 V	100 @ 150 mA, 10 V
Power (Max) [mW]	625	625	625	625	1000
Frequency - Transition [MHz]	210	250	100	210	150
Operating Temperature [°C]	-55 to 150	-55 to 150	to 150	-55 to 150	-55 to 200
Package	TO-92-3	TO-92-3	TO-92-3	TO-92	E-Line (TO-92 compatible)
Product Status	Obsolete	Active	Active	Active	Active
RoHS Status	Non-compliant	ROHS3 Compliant	Not specified	ROHS3 Compliant	ROHS3 Compliant

Engineering Selection Recommendations

BC33716BU (Fairchild Semiconductor) qualifies as a direct electrical substitute for the BC337. This part maintains identical maximum collector current (800 mA), collector-emitter breakdown voltage (45 V), saturation voltage characteristics, and power dissipation (625 mW). The TO-92-3 package provides mechanical compatibility. The part is currently in active production status, ensuring supply chain availability. Transition frequency is reduced to 100 MHz compared to the BC337's 210 MHz; this reduction does not impact applications operating below 100 MHz.

BC337-AP (Micro Commercial Co) provides functional equivalence with active product status and ROHS3 compliance. This part matches the BC337 in collector current, breakdown voltage, saturation voltage, and power dissipation. The TO-92 package with formed leads maintains mechanical compatibility. DC current gain specification differs (60 @ 300 mA versus 100 @ 100 mA), requiring verification in gain-sensitive applications. Transition frequency matches the original specification at 210 MHz.

2N4401BU (onsemi) operates as a compatible substitute with reduced maximum collector current (600 mA versus 800 mA) and collector-emitter breakdown voltage (40 V versus 45 V). This part is suitable for applications not requiring the full 800 mA current capability or 45 V voltage rating. The device is in active production with ROHS3 compliance. Transition frequency exceeds the original at 250 MHz, providing enhanced high-frequency performance.

ZTX450 (Diodes Incorporated) functions as a functional alternative with enhanced electrical specifications. Maximum collector current is increased to 1 A, and power dissipation is doubled to 1 W. The E-Line package is mechanically compatible with TO-92 form factors. This part is suitable for applications requiring higher current capacity or thermal headroom. Operating temperature range extends to 200°C, supporting elevated-temperature environments. Saturation voltage is significantly lower (250 mV), indicating superior switching performance in saturation-mode applications.

Frequently Asked Questions (FAQ)

Q: Can the BC337 be directly replaced with the 2N4401BU?

A: The 2N4401BU is a compatible substitute with electrical limitations. Maximum collector current is reduced to 600 mA (versus 800 mA), and collector-emitter breakdown voltage is 40 V (versus 45 V). Direct substitution is permissible only in applications operating below these reduced ratings. Verify circuit current and voltage requirements before selection.

Q: What is the primary difference between BC33716BU and the original BC337?

A: BC33716BU maintains identical electrical specifications for collector current, breakdown voltage, saturation voltage, and power dissipation. The transition frequency is reduced from 210 MHz to 100 MHz. For applications operating below 100 MHz, this substitution introduces no functional degradation. High-frequency applications above 100 MHz require evaluation of circuit performance.

Q: Is the BC337-AP suitable for all BC337 applications?

A: BC337-AP provides electrical equivalence with one specification variance: DC current gain is specified as 60 @ 300 mA instead of 100 @ 100 mA. Applications with gain-dependent biasing networks require circuit analysis to confirm acceptable performance. Collector current, breakdown voltage, and power dissipation are identical, supporting direct mechanical replacement.

Q: When should ZTX450 be selected over other substitutes?

A: ZTX450 is selected for applications requiring enhanced current capacity (1 A maximum), increased power dissipation (1 W), or operation in elevated-temperature environments (to 200°C). The significantly lower saturation voltage (250 mV) provides superior switching efficiency in saturation-mode circuits. Standard BC337 applications not requiring these enhancements should use BC33716BU or BC337-AP for closer electrical matching.

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

A: All substitute parts are available in Through Hole TO-92 or TO-92-3 packages with mechanical compatibility. BC33716BU, BC337-AP, and 2N4401BU use standard TO-92-3 form factors. ZTX450 uses an E-Line package, which maintains TO-92 mechanical compatibility. Verify lead spacing and PCB footprint compatibility for legacy designs.

Q: What compliance certifications apply to substitute parts?

A: BC33716BU compliance status is not specified in available documentation. BC337-AP and 2N4401BU are ROHS3 compliant. ZTX450 is ROHS3 compliant. The original BC337 is RoHS non-compliant. For applications requiring RoHS compliance, select BC337-AP, 2N4401BU, or ZTX450.

Q: Can BC337 substitutes be used interchangeably in existing designs?

A: Interchangeability depends on circuit-specific requirements. BC33716BU and BC337-AP provide the closest electrical equivalence and support direct substitution in most applications. 2N4401BU requires verification of current and voltage margins. ZTX450 is suitable for applications benefiting from enhanced specifications but may require thermal management evaluation. Conduct circuit simulation or prototype testing for gain-sensitive or high-frequency applications.

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