2SA733-P-AP PNP Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The 2SA733-P-AP is a PNP bipolar junction transistor manufactured by Micro Commercial Co, designed for small-signal switching and amplification applications. This device features a maximum collector current of 100 mA, collector-emitter breakdown voltage of 50 V, and power dissipation rating of 250 mW in a Through Hole TO-92 package. The 2SA733-P-AP is classified as obsolete, necessitating identification of active substitute components that maintain functional compatibility within specified electrical and mechanical parameters.

Substiute Parts

2SA733-P-AP

Micro Commercial CoIn Stock: 11842SA733-P-AP Datasheet

Current PartRFQ

BC557ATA

Fairchild SemiconductorIn Stock: 860BC557ATA Datasheet

MFR RecommendedRFQ

BC557BTA

onsemiIn Stock: 6210BC557BTA Datasheet

MFR RecommendedRFQ

BC557BTF

onsemiIn Stock: 41658BC557BTF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2SA733-P-AP is determined by strict equivalence in the following electrical and mechanical parameters:

Critical Matching Parameters:

• Transistor Type: PNP configuration
• Current - Collector (Ic) Max: 100 mA minimum
• Voltage - Collector Emitter Breakdown: 50 V minimum
• Mounting Type: Through Hole
• Package / Case: TO-92-3 compatible

Acceptable Parameter Variations: Substitute parts may exceed the original specifications in power dissipation, transition frequency, and collector-emitter saturation voltage without affecting functional compatibility. Substitute parts with collector-emitter breakdown voltage lower than 50 V are not acceptable for direct substitution.

The three identified substitute parts—BC557ATA, BC557BTA, and BC557BTF—all maintain PNP configuration, 100 mA collector current rating, and TO-92-3 package compatibility. However, all three substitutes feature a maximum collector-emitter breakdown voltage of 45 V, which is below the 50 V specification of the original 2SA733-P-AP. This represents a voltage derating that must be evaluated against circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

BC557BTF (onsemi) is the primary substitute option based on the following criteria:

• Active product status with highest inventory availability (41,626 pcs)
• ROHS3 compliance certification
• Electrical parameters exceed minimum requirements for collector current and power dissipation
• Transition frequency of 150 MHz exceeds original specification
• DC current gain of 200 @ 2mA, 5V matches the original specification

BC557BTA (onsemi) is the secondary substitute option:

• Active product status with substantial inventory (6,200 pcs)
• ROHS3 compliance certification
• Identical electrical specifications to BC557BTF
• Packaging in Cut Tape format may require reel management considerations

BC557ATA (Fairchild Semiconductor) is an alternative substitute option:

• Active product status with moderate inventory (779 pcs)
• Electrical specifications meet minimum requirements
• DC current gain of 110 @ 2mA, 5V is lower than the original specification
• Compliance certifications not fully specified in provided data

All three substitute parts operate at a maximum collector-emitter breakdown voltage of 45 V, representing a 5 V reduction from the original 2SA733-P-AP specification. Circuit designs operating near the 50 V maximum rating require evaluation to confirm compatibility with the 45 V substitute rating.

Frequently Asked Questions (FAQ)

Q: Can BC557BTF, BC557BTA, and BC557ATA be used interchangeably with 2SA733-P-AP?

A: All three parts share identical PNP configuration, 100 mA collector current rating, and TO-92-3 package compatibility. However, the 45 V collector-emitter breakdown voltage of the substitutes is 5 V lower than the original 2SA733-P-AP specification. Interchangeability depends on circuit voltage requirements. If the circuit operates below 45 V, substitution is acceptable. If circuit design requires the full 50 V rating, these substitutes are not suitable.

Q: What is the difference between BC557BTF and BC557BTA?

A: BC557BTF and BC557BTA are electrically identical. The primary difference is packaging format: BC557BTF is supplied in Cut Tape (CT) format with higher inventory availability (41,626 pcs), while BC557BTA is also supplied in Cut Tape format with lower inventory (6,200 pcs). Both carry ROHS3 compliance certification.

Q: Why does BC557ATA have a lower DC current gain specification?

A: BC557ATA specifies a minimum DC current gain of 110 @ 2mA, 5V, compared to 200 @ 2mA, 5V for BC557BTA and BC557BTF. This represents a different device grade within the BC557 family. Applications requiring higher current gain should select BC557BTA or BC557BTF.

Q: Are the substitute parts RoHS compliant?

A: BC557BTA and BC557BTF carry ROHS3 compliance certification. BC557ATA compliance status is not specified in the provided data. For applications requiring RoHS certification, BC557BTA or BC557BTF are recommended.

Q: What is the impact of the 45 V versus 50 V collector-emitter breakdown voltage difference?

A: The 5 V reduction in maximum breakdown voltage represents a design margin reduction. Circuits operating at voltages below 45 V experience no functional impact. Circuits designed to operate near 50 V require verification that actual operating voltages remain below 45 V to prevent device damage.

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

A: All substitute parts feature transition frequency of 150 MHz, exceeding the original 2SA733-P-AP specification of 100 MHz. This provides improved high-frequency performance and is suitable for applications requiring frequencies up to 150 MHz.

Q: What is the operating temperature range for the substitute parts?

A: The provided data specifies a maximum junction temperature (TJ) of 150°C for all substitute parts. The original 2SA733-P-AP specifies an operating range of -55°C to 150°C. Substitute parts are suitable for applications within the 150°C maximum junction temperature limit.