BD158STU Equivalent & Substitute Parts

Part Overview

The BD158STU is an NPN bipolar junction transistor manufactured by onsemi, rated for 300 V collector-emitter breakdown voltage and 500 mA maximum collector current in a TO-126-3 through-hole package. This device is classified as obsolete, making equivalent substitute parts necessary for ongoing production and maintenance applications. The BD158STU delivers 20 W maximum power dissipation and provides a minimum DC current gain of 30 at 50 mA collector current and 10 V collector-emitter voltage.

Substiute Parts

BD158STU

onsemiIn Stock: 1265BD158STU Datasheet

Current PartRFQ

MJE340G

onsemiIn Stock: 6945MJE340G Datasheet

DirectRFQ

MJE340

NTE Electronics, IncIn Stock: 2035MJE340 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BD158STU are qualified based on matching the following critical electrical and mechanical parameters:

• Transistor Type: NPN configuration
• Voltage - Collector Emitter Breakdown (Max): 300 V
• Current - Collector (Ic) (Max): 500 mA
• DC Current Gain (hFE) (Min) @ Ic, Vce: 30 @ 50mA, 10V
• Power - Max: 20 W
• Mounting Type: Through Hole
• Package / Case: TO-126-3 or TO-126 (mechanically compatible)

All substitute parts listed below satisfy these electrical and mechanical requirements and are therefore direct functional equivalents for the BD158STU in applications requiring these specifications.

Parameter Comparison

Engineering Selection Recommendations

MJE340G (onsemi) is the primary substitute for the BD158STU. This part is manufactured by onsemi, the same original manufacturer of the BD158STU, and maintains active product status. The MJE340G is RoHS3 compliant and carries REACH Unaffected status, meeting current environmental and regulatory requirements. Inventory availability is substantial at 6900 pieces. The operating temperature range is specified as −65°C to 150°C (TJ).

MJE340 (NTE Electronics, Inc) is an alternative substitute manufactured by NTE Electronics, Inc. This part is also in active production status with 1957 pieces in inventory. However, the MJE340 from NTE Electronics is RoHS non-compliant and does not specify the collector cutoff current parameter. This part is suitable for applications where RoHS compliance is not required.

For new designs and applications requiring regulatory compliance, MJE340G is the recommended substitute. For legacy systems or applications without RoHS requirements, MJE340 from NTE Electronics provides functional equivalence.

Frequently Asked Questions (FAQ)

Q: Can the MJE340G directly replace the BD158STU in existing circuits?

A: Yes. The MJE340G matches all critical electrical parameters of the BD158STU: 300 V collector-emitter breakdown voltage, 500 mA maximum collector current, 20 W power dissipation, and 30 minimum DC current gain at the specified test conditions. The TO-126 package is mechanically compatible with TO-126-3 applications.

Q: What is the difference between MJE340G and MJE340?

A: Both parts are electrically equivalent and meet the same performance specifications. The primary differences are manufacturer (onsemi versus NTE Electronics, Inc), RoHS compliance status (MJE340G is RoHS3 compliant; MJE340 is non-compliant), and packaging format (MJE340G supplied in bulk; MJE340 supplied in bag). The MJE340G also specifies operating temperature range and collector cutoff current, while the MJE340 does not provide these parameters.

Q: Are there any package compatibility concerns when substituting these parts?

A: No. The BD158STU uses TO-126-3 packaging, while both substitute parts use TO-126 packaging. These packages are mechanically and electrically compatible for through-hole mounting applications. Pin configuration and lead spacing are identical.

Q: Why is the BD158STU classified as obsolete?

A: The BD158STU is no longer in active production. The MJE340 series represents the current active product line offering equivalent electrical performance and specifications.

Q: Which substitute should be selected for new product designs?

A: MJE340G is the appropriate choice for new designs. It is manufactured by onsemi, maintains active product status, and meets RoHS3 compliance requirements. The specified operating temperature range of −65°C to 150°C (TJ) provides clear thermal operating boundaries for design validation.

Q: Can the MJE340 from NTE Electronics be used in applications requiring RoHS compliance?

A: No. The MJE340 from NTE Electronics is RoHS non-compliant and is not suitable for applications or markets requiring RoHS certification. MJE340G must be used in such applications.