MJE340STU Equivalent & Substitute Parts

Part Overview

The MJE340STU 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 product status. Equivalent and substitute parts are necessary to maintain design continuity and ensure component availability for production and repair applications where the original MJE340STU is no longer readily procurable.

Substiute Parts

MJE340STU

onsemiIn Stock: 2116MJE340STU Datasheet

Current PartRFQ

MJE340G

onsemiIn Stock: 6945MJE340G Datasheet

DirectRFQ

MJE340

NTE Electronics, IncIn Stock: 2035MJE340 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MJE340STU is determined by strict equivalence across the following electrical and mechanical parameters:

Critical Matching Parameters:

• Transistor Type: NPN
• Current - Collector (Ic) Max: 500 mA
• Voltage - Collector Emitter Breakdown (Max): 300 V
• DC Current Gain (hFE) Min @ Ic, Vce: 30 @ 50mA, 10V
• Power - Max: 20 W
• Mounting Type: Through Hole
• Package / Case: TO-126-3 or equivalent TO-225AA

All substitute parts listed below meet these electrical specifications and are compatible with the original MJE340STU pinout and footprint requirements.

Parameter Comparison

Engineering Selection Recommendations

MJE340G (onsemi) is the primary substitute for MJE340STU. Both parts are manufactured by onsemi, share identical electrical specifications, and are pin-compatible in TO-126-3 packaging. MJE340G maintains active product status with ROHS3 compliance and an extended operating temperature range of -65°C to 150°C, providing superior environmental performance compared to the obsolete MJE340STU. Inventory availability is 6900 units.

MJE340 (NTE Electronics, Inc) is a secondary substitute option. This part meets all critical electrical parameters and maintains through-hole TO-126-3 package compatibility. However, NTE Electronics MJE340 is RoHS non-compliant, which may restrict use in applications requiring regulatory compliance. Inventory availability is 1957 units.

For new designs and applications requiring regulatory compliance, MJE340G is the recommended selection. For legacy system repairs where RoHS compliance is not a constraint, MJE340 (NTE Electronics) provides an alternative source.

Frequently Asked Questions (FAQ)

Q: Can MJE340G directly replace MJE340STU in existing circuit designs?

A: Yes. MJE340G is electrically and mechanically equivalent to MJE340STU. Both devices share identical collector current (500 mA), collector-emitter breakdown voltage (300 V), DC current gain (30 @ 50mA, 10V), and power dissipation (20 W) specifications. Pin configuration and TO-126-3 package dimensions are identical, enabling direct substitution without circuit modification.

Q: What is the difference between MJE340STU and MJE340G?

A: The primary differences are product status and operating temperature range. MJE340STU is classified as obsolete with a maximum operating temperature of 150°C. MJE340G is active product with an extended operating temperature range of -65°C to 150°C. Both parts are manufactured by onsemi and are electrically identical.

Q: Is the NTE Electronics MJE340 suitable for RoHS-compliant applications?

A: No. The NTE Electronics MJE340 is marked as RoHS non-compliant. Applications requiring RoHS compliance must use MJE340G (onsemi), which carries ROHS3 compliance certification.

Q: Are there package differences between the substitute parts?

A: All three parts use TO-126-3 through-hole packaging with identical pinout and footprint. No PCB layout modifications are required when substituting between MJE340STU, MJE340G, and NTE Electronics MJE340.

Q: What is the current availability of substitute parts?

A: MJE340G (onsemi) has 6900 units in stock. MJE340 (NTE Electronics) has 1957 units in stock. MJE340STU (original part) has 2100 units in stock but is obsolete product.