BF245C Equivalent & Substitute Parts

Part Overview

The BF245C is an N-Channel JFET RF transistor manufactured by onsemi, housed in a TO-92-3 through-hole package. This device is classified as obsolete, indicating it is no longer in active production. The BF245C was designed for RF applications requiring low-noise amplification in the VHF frequency range, with a rated voltage of 30V and maximum drain current of 25mA.

Due to its obsolete status, locating new original inventory of the BF245C presents supply chain challenges. Identifying functionally equivalent substitute parts ensures design continuity and maintains access to compatible RF JFET solutions with comparable electrical characteristics and performance parameters.

Substiute Parts

BF245C

onsemiIn Stock: 3374BF245C Datasheet

Current PartRFQ

MMBF5485

onsemiIn Stock: 65234MMBF5485 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BF245C requires matching the following critical parameters:

Technology & Configuration: The substitute must be an N-Channel JFET to maintain identical circuit operation and biasing characteristics.

Voltage Rating: The substitute's rated voltage must equal or exceed the BF245C specification of 30V to ensure safe operation within the original design envelope.

Current Rating: The substitute's maximum drain current must meet or exceed 25mA to support the intended load conditions.

Mounting Type & Package: The original design uses through-hole mounting in a TO-92-3 package. Substitutes with different mounting types (surface mount) or packages (SOT-23-3) require PCB redesign and are classified as design modifications rather than direct substitutions.

The MMBF5485 is identified as a substitute part in the provided data. However, this device presents the following parameter deviations:

• Mounting Type: Surface mount (SOT-23-3) versus through-hole (TO-92-3)
• Voltage - Rated: 25V versus 30V (reduced rating)
• Current Rating: 10mA versus 25mA (reduced capability)

These differences indicate that MMBF5485 is not a direct pin-compatible or electrical equivalent for through-hole applications requiring the full 30V/25mA specification.

Parameter Comparison

Engineering Selection Recommendations

For Direct Through-Hole Replacement: No direct substitute meeting all electrical and mechanical specifications is available in the provided data. The BF245C's combination of 30V rating, 25mA current capability, and TO-92-3 through-hole package is not matched by the MMBF5485, which operates at reduced voltage and current ratings in a surface-mount package.

For Active Production Designs: The MMBF5485 is classified as active product status, ensuring ongoing availability and supply chain stability. However, its selection requires design modification to accommodate surface-mount assembly and reduced electrical specifications.

Compliance Considerations: Both devices maintain REACH Unaffected status and MSL 1 (Unlimited) moisture sensitivity, indicating equivalent environmental compliance and handling requirements.

Inventory Status: The BF245C maintains 3,349 pieces of new original stock despite obsolete classification. The MMBF5485 provides significantly higher inventory availability at 65,200 pieces, supporting long-term supply security for new designs.

Frequently Asked Questions (FAQ)

Q: Can MMBF5485 directly replace BF245C in existing through-hole PCB designs?

A: No. The MMBF5485 uses surface-mount SOT-23-3 packaging, requiring PCB redesign and assembly process modification. Direct pin-compatible replacement is not possible.

Q: What are the electrical limitations of using MMBF5485 as a substitute?

A: The MMBF5485 has a maximum rated voltage of 25V compared to the BF245C's 30V specification, and a maximum drain current of 10mA versus 25mA. Applications requiring the full 30V/25mA envelope cannot use this substitute without circuit redesign.

Q: Are both devices from the same manufacturer?

A: Yes. Both BF245C and MMBF5485 are manufactured by onsemi, ensuring consistent quality standards and design philosophy.

Q: What is the significance of the BF245C being classified as obsolete?

A: Obsolete status indicates the device is no longer manufactured. While current inventory exists, future availability is not guaranteed. Design migration to active-status alternatives is recommended for new production programs.

Q: Do both devices have identical moisture sensitivity requirements?

A: Yes. Both devices are classified as MSL 1 (Unlimited), indicating no moisture sensitivity restrictions for storage, handling, or assembly processes.

Q: What is the primary reason to consider substitution?

A: The BF245C's obsolete status creates long-term supply risk. Although inventory is currently available, substitution planning ensures design continuity when stock is depleted.

Q: Are there any compliance differences between these devices?

A: No. Both devices maintain identical REACH Unaffected status and equivalent environmental compliance classifications.