BC237B-AP Equivalent & Substitute Parts

Part Overview

The BC237B-AP is a small-signal NPN bipolar junction transistor manufactured by Micro Commercial Co, designed for general-purpose switching and amplification applications. This device operates at a maximum collector voltage of 45 V with a collector current rating of 100 mA and a maximum power dissipation of 350 mW. The BC237B-AP is classified as obsolete, which necessitates identification of active equivalent and substitute parts for ongoing design requirements and procurement needs. Substitute parts must maintain electrical and mechanical compatibility while meeting current availability and compliance standards.

Substiute Parts

BC237B-AP

Micro Commercial CoIn Stock: 931BC237B-AP Datasheet

Current PartRFQ

BC547BTA

Fairchild SemiconductorIn Stock: 1332BC547BTA Datasheet

DirectRFQ

BC550CTA

onsemiIn Stock: 13803BC550CTA Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BC237B-AP are qualified based on strict electrical and mechanical parameter matching. The following criteria determine substitution eligibility:

Critical Matching Parameters:

• Transistor Type: NPN (required match)
• Current - Collector (Ic) Max: 100 mA (required match)
• Voltage - Collector Emitter Breakdown (Max): 45 V (required match)
• Vce Saturation (Max) @ Ib, Ic: 600 mV @ 5 mA, 100 mA (required match)
• Current - Collector Cutoff (Max): 15 nA (required match)
• DC Current Gain (hFE) Min @ Ic, Vce: 200 @ 2 mA, 5 V (required match)
• Mounting Type: Through Hole (required match)
• Package / Case: TO-92-3 (required match)

Allowable Parameter Variations:

• Power - Max: Substitute parts may exceed the original specification
• Frequency - Transition: Substitute parts may exceed the original specification
• Operating Temperature Range: Substitute parts may provide extended temperature range
• Product Status: Active status preferred for ongoing availability

The BC547BTA and BC550CTA meet all critical electrical and mechanical parameters while offering enhanced performance characteristics and active product status.

Parameter Comparison

Engineering Selection Recommendations

BC547BTA (Fairchild Semiconductor)

The BC547BTA is a direct functional equivalent to the BC237B-AP. This device maintains all critical electrical parameters including collector current, breakdown voltage, saturation voltage, and DC current gain. The BC547BTA offers enhanced performance with increased power dissipation (625 mW versus 350 mW) and higher transition frequency (300 MHz versus 200 MHz). The extended operating temperature range (-55°C to 150°C) provides additional thermal margin. Active product status ensures long-term availability and supply chain continuity. The TO-92-3 package provides mechanical compatibility with existing through-hole designs.

BC550CTA (onsemi)

The BC550CTA is a functionally compatible substitute with all critical electrical parameters matched to the BC237B-AP. This device provides increased power dissipation (500 mW versus 350 mW) and higher transition frequency (300 MHz versus 200 MHz). The DC current gain specification (420 @ 2 mA, 5 V) exceeds the minimum requirement of 200, offering improved gain characteristics. Active product status and RoHS3 compliance ensure regulatory alignment and supply availability. The TO-92-3 package maintains mechanical compatibility with through-hole circuit board designs.

Selection Basis

Both substitute parts satisfy all mandatory electrical and mechanical compatibility requirements. Selection between BC547BTA and BC550CTA depends on specific application requirements regarding power dissipation margin, current gain characteristics, and supplier availability. Both devices are active products with established supply chains, providing superior long-term availability compared to the obsolete BC237B-AP.

Frequently Asked Questions (FAQ)

Q: Can the BC547BTA or BC550CTA be used as direct replacements for the BC237B-AP in existing circuit designs?

A: Yes. Both substitute parts maintain all critical electrical parameters: 100 mA collector current, 45 V breakdown voltage, 600 mV saturation voltage, 15 nA cutoff current, and 200 minimum DC current gain. The TO-92-3 package provides identical through-hole pin configuration and mechanical compatibility.

Q: What are the key differences between the BC547BTA and BC550CTA?

A: The BC547BTA provides maximum power dissipation of 625 mW and operating temperature range of -55°C to 150°C. The BC550CTA provides maximum power dissipation of 500 mW and maximum operating temperature of 150°C. The BC550CTA specifies a higher minimum DC current gain of 420 compared to 200 for the BC547BTA. Both devices operate at 300 MHz transition frequency.

Q: Are there any compliance or certification differences between the substitute parts?

A: The BC547BTA is manufactured by Fairchild Semiconductor. The BC550CTA is manufactured by onsemi and carries RoHS3 compliance and REACH Unaffected status. Both devices are classified under ECCN EAR99 and HTSUS 8541.21.0075. Verify specific compliance requirements for your application and supply chain.

Q: Can the BC237B-AP be used interchangeably with these substitutes in reverse?

A: No. The BC237B-AP is classified as obsolete and carries lower power dissipation (350 mW) and transition frequency (200 MHz) specifications. While the BC237B-AP meets the minimum electrical requirements, its obsolete status and reduced performance characteristics make it unsuitable for new designs or as a replacement for active substitute parts.

Q: What packaging options are available for these substitute parts?

A: The BC547BTA is supplied in Bulk packaging. The BC550CTA is supplied in Cut Tape (CT) packaging. Both devices are available in TO-92-3 package configuration for through-hole mounting. Verify packaging availability with your supplier for procurement requirements.

Q: Are there any thermal or frequency performance advantages to using the substitute parts?

A: Yes. Both BC547BTA and BC550CTA provide higher transition frequency (300 MHz versus 200 MHz) and increased power dissipation capability (625 mW and 500 mW respectively versus 350 mW). These enhancements allow operation in higher-frequency applications and provide thermal margin for power-dissipating circuits. The BC547BTA additionally provides extended operating temperature range (-55°C to 150°C).