BF240_D74Z Equivalent & Substitute Parts

Part Overview

The BF240_D74Z is an RF transistor NPN manufactured by onsemi, designed for radio frequency applications operating at 1.1GHz with a maximum collector-emitter breakdown voltage of 40V and power dissipation of 350mW. The device is packaged in a through-hole TO-92-3 configuration and is classified as obsolete. Due to its obsolete status, equivalent substitute parts are necessary for new designs, production continuity, and system maintenance where the BF240_D74Z is no longer available from primary sources.

Substiute Parts

BF240_D74Z

onsemiIn Stock: 1129BF240_D74Z Datasheet

Current PartRFQ

2SC4713KT146R

Rohm SemiconductorIn Stock: 17872SC4713KT146R Datasheet

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BFP740FESDH6327XTSA1

Infineon TechnologiesIn Stock: 6064BFP740FESDH6327XTSA1 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the BF240_D74Z is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Transistor Type: NPN configuration required
• Voltage - Collector Emitter Breakdown (Max): Must equal or exceed 40V
• Frequency - Transition: Must support 1.1GHz operation or higher
• Power - Max: Must accommodate 350mW dissipation or higher
• Current - Collector (Ic) (Max): Must support 50mA or higher
• DC Current Gain (hFE): Must provide sufficient gain for circuit operation

Mechanical Compatibility Criteria:

• Mounting Type: Through Hole preferred for direct replacement; Surface Mount alternatives require board redesign
• Package / Case: TO-92-3 for direct pin-compatible replacement; alternative packages require layout modification

The substitute parts listed below are grouped based on their ability to meet these electrical specifications within their respective packaging constraints. Surface mount alternatives (2SC4713KT146R and BFP740FESDH6327XTSA1) represent functional equivalents but require different mounting approaches and board layout considerations compared to the through-hole BF240_D74Z.

Parameter Comparison

Engineering Selection Recommendations

Direct Through-Hole Replacement: No direct through-hole equivalent is available among the listed substitutes. Both substitute parts employ surface mount packaging, requiring circuit board redesign for implementation.

Surface Mount Alternatives:

2SC4713KT146R (Rohm Semiconductor): This part is active and ROHS3 compliant. It provides NPN functionality with 50mA collector current capability. However, the voltage rating (6V maximum) and power dissipation (200mW) are significantly reduced compared to the BF240_D74Z. The frequency capability (800MHz) is lower than the original specification. This substitute is suitable only for applications where the reduced voltage and power ratings are acceptable and frequency requirements do not exceed 800MHz.

BFP740FESDH6327XTSA1 (Infineon Technologies): This part is active and ROHS3 compliant. It provides NPN functionality with superior frequency capability (47GHz) and higher current gain. However, the voltage rating (4.7V maximum) and power dissipation (160mW) are substantially reduced compared to the BF240_D74Z. This substitute is suitable for high-frequency applications where the reduced voltage and power ratings are acceptable.

Both substitutes maintain MSL 1 (Unlimited) moisture sensitivity classification and REACH compliance status consistent with the original part.

Frequently Asked Questions (FAQ)

Q: Can the 2SC4713KT146R directly replace the BF240_D74Z in an existing circuit?

A: Direct replacement is not recommended. The 2SC4713KT146R has a maximum collector-emitter breakdown voltage of 6V compared to the BF240_D74Z specification of 40V. If the circuit operates at voltages exceeding 6V, the substitute will fail. Additionally, the surface mount package (SOT-23-3) differs from the through-hole TO-92-3 package, requiring board redesign.

Q: What are the voltage limitations of the substitute parts?

A: The 2SC4713KT146R is rated for 6V maximum collector-emitter breakdown voltage. The BFP740FESDH6327XTSA1 is rated for 4.7V maximum. Both are significantly lower than the BF240_D74Z specification of 40V. Applications requiring operation above these voltage levels cannot use these substitutes.

Q: How do the frequency capabilities compare?

A: The BF240_D74Z operates at 1.1GHz transition frequency. The 2SC4713KT146R supports 800MHz, which is below the original specification. The BFP740FESDH6327XTSA1 supports 47GHz, which exceeds the original specification. Frequency selection depends on circuit requirements.

Q: Are the substitute parts available in through-hole packaging?

A: No. Both listed substitutes are surface mount devices. The 2SC4713KT146R uses SOT-23-3 packaging, and the BFP740FESDH6327XTSA1 uses 4-TSFP packaging. Through-hole implementation requires either sourcing alternative parts or redesigning the circuit board for surface mount assembly.

Q: What is the power dissipation difference?

A: The BF240_D74Z is rated for 350mW maximum power dissipation. The 2SC4713KT146R is rated for 200mW, and the BFP740FESDH6327XTSA1 is rated for 160mW. Applications requiring power dissipation above these levels cannot use these substitutes without thermal management modifications.

Q: Are the substitute parts RoHS compliant?

A: Yes. Both 2SC4713KT146R and BFP740FESDH6327XTSA1 are ROHS3 compliant. The original BF240_D74Z does not specify RoHS status in the provided data.

Q: What is the current gain difference between parts?

A: The BF240_D74Z specifies minimum hFE of 65 @ 1mA, 10V. The 2SC4713KT146R specifies minimum hFE of 180 @ 5mA, 5V. The BFP740FESDH6327XTSA1 specifies minimum hFE of 160 @ 25mA, 3V. Higher gain values in substitutes may require circuit bias adjustments.

Q: Can I use these substitutes in high-voltage applications?

A: No. Both substitute parts have significantly lower voltage ratings (6V and 4.7V respectively) compared to the BF240_D74Z (40V). High-voltage applications must source alternative parts with appropriate voltage specifications.