J201 JFET N-Channel Transistor Equivalent & Substitute Parts

Part Overview

The J201 is an N-Channel JFET transistor rated for 40 V breakdown voltage with a maximum power dissipation of 625 mW in a Through Hole TO-92-3 package. This device is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing design support and production continuity. The J201 operates across a wide temperature range of -55°C to 150°C and is suitable for applications requiring low-noise signal switching and amplification in analog circuits.

Substiute Parts

J201

onsemiIn Stock: 3251J201 Datasheet

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MMBFJ201

onsemiIn Stock: 76135MMBFJ201 Datasheet

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J201 TO-92 3L ROHS

Linear Integrated Systems, Inc.In Stock: 1040J201 TO-92 3L ROHS Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the J201 is determined by strict electrical parameter matching and package compatibility. The critical parameters that define substitutability are:

• N-Channel JFET topology
• 40 V breakdown voltage (V(BR)GSS)
• 200 µA drain current (Idss) at specified conditions
• 300 mV cutoff voltage (VGS off)
• Operating temperature range of -55°C to 150°C
• Package form factor (Through Hole TO-92-3 or Surface Mount SOT-23-3)

Substitute parts are grouped into two categories based on mounting technology: Through Hole equivalents maintain the original TO-92-3 footprint, while Surface Mount equivalents provide electrical equivalence in SOT-23-3 packaging for modern PCB designs.

Parameter Comparison

Engineering Selection Recommendations

For Through Hole applications requiring direct footprint compatibility with the original J201, the J201 TO-92 3L ROHS from Linear Integrated Systems, Inc. provides electrical equivalence with active product status and ROHS3 compliance. This part maintains the TO-92-3 package geometry while offering improved regulatory compliance.

For Surface Mount designs or new board layouts, the MMBFJ201 from onsemi delivers electrical equivalence in SOT-23-3 packaging with active product status and ROHS3 compliance. The MMBFJ201 is suitable for applications where power dissipation does not exceed 350 mW, as this represents the maximum rating for the surface mount variant.

Both substitute parts maintain the core electrical characteristics of the J201: 40 V breakdown voltage, 200 µA drain current, and 300 mV cutoff voltage across the full -55°C to 150°C operating temperature range. Selection between substitutes depends on PCB assembly technology and thermal design requirements.

Frequently Asked Questions (FAQ)

Q: Can the MMBFJ201 replace the J201 in all applications?

A: The MMBFJ201 provides electrical equivalence but differs in maximum power dissipation (350 mW vs. 625 mW) and mounting technology (Surface Mount SOT-23-3 vs. Through Hole TO-92-3). Applications requiring power dissipation above 350 mW or existing Through Hole PCB layouts should use the J201 TO-92 3L ROHS instead.

Q: What is the primary reason the J201 is obsolete?

A: The J201 is classified as obsolete by the original manufacturer. The J201 TO-92 3L ROHS and MMBFJ201 are active alternatives that provide equivalent electrical performance with current manufacturing support.

Q: Are all substitute parts ROHS compliant?

A: The MMBFJ201 and J201 TO-92 3L ROHS are both ROHS3 compliant. The original J201 is listed as REACH Unaffected. All parts carry EAR99 export classification and are suitable for regulated applications.

Q: How do the electrical parameters compare across all three parts?

A: All three parts share identical breakdown voltage (40 V), cutoff voltage (300 mV @ 10 nA), and operating temperature range (-55°C to 150°C). Drain current (Idss) is specified at 200 µA with minor variations in measurement conditions. The primary differences are power rating and package form factor.

Q: Which substitute should be used for new designs?

A: For new designs, select based on assembly technology: MMBFJ201 for Surface Mount assembly, or J201 TO-92 3L ROHS for Through Hole assembly. Both are active products with full manufacturer support and regulatory compliance.