BC337-40BK Equivalent & Substitute Parts

Part Overview

The BC337-40BK is an NPN bipolar junction transistor manufactured by Diotec Semiconductor, designed for general-purpose switching and amplification applications. This through-hole component operates at a maximum collector current of 800 mA with a collector-emitter breakdown voltage of 45 V and a maximum power dissipation of 625 mW. The device is currently in active production status. Substitute parts are identified when equivalent electrical specifications and mechanical compatibility allow direct replacement in circuit designs without functional degradation.

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	700mV @ 50mA, 500mA	V
Current - Collector Cutoff (Max)	100	nA
DC Current Gain (hFE) (Min) @ Ic, Vce	250 @ 100mA, 1V	—
Power - Max	625	mW
Frequency - Transition	100	MHz
Mounting Type	Through Hole	—
Package / Case	TO-92-3	—

Substitute Part Grouping Explanation

Substitution of the BC337-40BK is determined by strict equivalence across all critical electrical and mechanical parameters. The substitute part BC33740BU is classified as a parametric equivalent based on the following criteria:

Electrical Parameter Equivalence:

Identical maximum collector current (800 mA)
Identical collector-emitter breakdown voltage (45 V)
Identical saturation voltage characteristics (700mV @ 50mA, 500mA)
Identical collector cutoff current (100 nA)
Identical DC current gain specification (250 @ 100mA, 1V)
Identical maximum power dissipation (625 mW)
Identical transition frequency (100 MHz)

Mechanical Compatibility:

Identical mounting type (Through Hole)
Identical package designation (TO-92-3)
Identical pin configuration (TO-226-3, TO-92-3)

The substitute part maintains full functional equivalence and can be used interchangeably in applications designed for the BC337-40BK.

Parameter Comparison

Parameter	BC337-40BK (Diotec)	BC33740BU (onsemi)	Match
Transistor Type	NPN	NPN	✓
Current - Collector (Ic) (Max)	800 mA	800 mA	✓
Voltage - Collector Emitter Breakdown (Max)	45 V	45 V	✓
Vce Saturation (Max) @ Ib, Ic	700mV @ 50mA, 500mA	700mV @ 50mA, 500mA	✓
Current - Collector Cutoff (Max)	100 nA	100 nA	✓
DC Current Gain (hFE) (Min) @ Ic, Vce	250 @ 100mA, 1V	250 @ 100mA, 1V	✓
Power - Max	625 mW	625 mW	✓
Frequency - Transition	100 MHz	100 MHz	✓
Mounting Type	Through Hole	Through Hole	✓
Package / Case	TO-92-3	TO-92-3	✓
Product Status	Active	Active	✓

Engineering Selection Recommendations

Both the BC337-40BK and BC33740BU are active production components with full electrical and mechanical equivalence. Selection between these parts is based on availability, packaging format, and compliance requirements:

BC337-40BK (Diotec Semiconductor): Supplied in box packaging. RoHS status is not applicable. REACH status is vendor undefined.

BC33740BU (onsemi): Supplied in bulk packaging. RoHS3 compliant. REACH unaffected status.

For applications requiring RoHS3 compliance certification, the BC33740BU is the appropriate selection. For applications without specific compliance mandates, either part provides equivalent performance. Packaging format (box versus bulk) should be evaluated based on procurement and inventory management requirements.

Frequently Asked Questions (FAQ)

Q: Can BC33740BU replace BC337-40BK in existing circuit designs?

A: Yes. The BC33740BU is a parametric equivalent with identical electrical specifications and mechanical compatibility. Direct substitution is supported without circuit modification.

Q: Are there differences in the TO-92-3 package between manufacturers?

A: No. Both parts use the identical TO-92-3 package designation with the same pin configuration and physical dimensions. Pin-for-pin replacement is supported.

Q: What is the difference between box and bulk packaging?

A: Box packaging (BC337-40BK) provides individual component packaging suitable for smaller quantity orders. Bulk packaging (BC33740BU) provides components in larger quantities without individual packaging, typically for high-volume manufacturing operations.

Q: Does the operating temperature range differ between these parts?

A: The BC337-40BK specifies an operating temperature range of -55°C to 150°C. The BC33740BU specifies a maximum operating temperature of 150°C. Both parts support the standard industrial operating range.

Q: Which part should be selected for new designs?

A: Selection is based on compliance requirements and supply chain considerations. For RoHS3-compliant applications, BC33740BU is specified. For applications without compliance mandates, either part is acceptable based on availability and packaging preference.

Q: Are there any electrical performance differences between these transistors?

A: No. All electrical parameters including maximum collector current, breakdown voltage, saturation characteristics, current gain, power dissipation, and transition frequency are identical between BC337-40BK and BC33740BU.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message