BC328-40-AP Equivalent & Substitute Parts

Part Overview

The BC328-40-AP is a PNP bipolar junction transistor manufactured by Micro Commercial Co, designed for general-purpose switching and amplification applications. This device features a maximum collector current of 800 mA, collector-emitter breakdown voltage of 25 V, and maximum power dissipation of 625 mW in a Through Hole TO-92 package.

The BC328-40-AP is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications utilizing this transistor.

Substiute Parts

BC328-40-AP

Micro Commercial CoIn Stock: 709BC328-40-AP Datasheet

Current PartRFQ

BC32740TA

onsemiIn Stock: 4970BC32740TA Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BC328-40-AP is determined by electrical and mechanical compatibility within the following parameters:

Critical Matching Parameters:

• Transistor polarity (PNP)
• Maximum collector current (800 mA minimum)
• Maximum power dissipation (625 mW minimum)
• DC current gain (hFE ≥ 250 @ 100mA, 1V)
• Vce saturation characteristics (700mV @ 50mA, 500mA)
• Through Hole mounting configuration
• TO-92-3 package compatibility

Allowable Variation Parameters:

• Collector-emitter breakdown voltage (equal to or greater than 25 V)
• Transition frequency (equal to or greater than 100 MHz)
• Collector cutoff current (equal to or less than 200 nA)
• Operating temperature range (minimum -55°C to 150°C coverage)

The BC32740TA qualifies as a direct substitute based on these criteria. This part maintains identical collector current, power dissipation, DC current gain, and saturation characteristics while providing enhanced voltage rating (45 V) and compatible package configuration.

Parameter Comparison

Engineering Selection Recommendations

BC32740TA Substitution Assessment:

The BC32740TA is a direct functional substitute for the BC328-40-AP in applications where the original part is unavailable. Both devices maintain identical electrical performance in collector current, power dissipation, DC current gain, and saturation voltage characteristics.

The BC32740TA provides enhanced specifications in two areas: collector-emitter breakdown voltage (45 V versus 25 V) and lower collector cutoff current (100 nA versus 200 nA). These improvements ensure compatibility with the original design while providing additional design margin.

The BC32740TA operates at a lower transition frequency (100 MHz versus 260 MHz). This characteristic is acceptable for applications where the original 260 MHz specification was not a critical design requirement. For high-frequency switching applications requiring transition frequencies above 100 MHz, frequency performance must be evaluated against specific circuit requirements.

Both parts are RoHS3 compliant and utilize identical TO-92-3 Through Hole packaging, ensuring mechanical and thermal compatibility. The BC32740TA is classified as Active product status, providing long-term supply availability compared to the obsolete BC328-40-AP.

Frequently Asked Questions (FAQ)

Q: Can the BC32740TA directly replace the BC328-40-AP in existing designs?

A: Yes. The BC32740TA maintains identical collector current (800 mA), power dissipation (625 mW), DC current gain (250 @ 100mA, 1V), and saturation voltage characteristics (700mV @ 50mA, 500mA). The TO-92-3 package is mechanically and thermally compatible. No circuit modifications are required for standard switching and amplification applications.

Q: What is the significance of the higher breakdown voltage in the BC32740TA?

A: The BC32740TA provides 45 V collector-emitter breakdown voltage compared to 25 V in the BC328-40-AP. This higher rating provides additional design margin and allows operation in circuits with higher supply voltages. The original design specifications are maintained; the higher rating does not negatively impact performance.

Q: Does the lower transition frequency of the BC32740TA affect compatibility?

A: The BC32740TA operates at 100 MHz transition frequency compared to 260 MHz in the BC328-40-AP. For applications where high-frequency switching performance was not a critical design parameter, this difference is not significant. Applications requiring transition frequencies above 100 MHz must evaluate whether the substitute meets specific frequency requirements.

Q: Are both parts available in the same package configuration?

A: Yes. Both the BC328-40-AP and BC32740TA utilize the TO-92-3 Through Hole package with formed leads. Pin configuration and physical dimensions are compatible, allowing direct board-level substitution without layout modifications.

Q: What is the compliance status of the BC32740TA?

A: The BC32740TA is RoHS3 compliant and classified as Active product status. This ensures regulatory compliance and long-term supply chain availability for production applications.

Q: Are there any thermal considerations when substituting these parts?

A: Both parts are rated for 625 mW maximum power dissipation and utilize identical TO-92-3 packaging. Thermal performance and heat dissipation characteristics are equivalent. Existing thermal management provisions in the original design remain applicable.