KSA708YBU Equivalent & Substitute Parts

Part Overview

The KSA708YBU is an active PNP bipolar junction transistor manufactured by onsemi, designed for general-purpose switching and amplification applications. This Through Hole TO-92-3 package device operates at maximum ratings of 60V collector-emitter breakdown voltage and 700mA collector current, with 800mW maximum power dissipation. The device is RoHS3 compliant and REACH unaffected, making it suitable for modern electronic applications. Equivalent and substitute parts are identified to provide design flexibility, support supply chain continuity, and accommodate specific application requirements such as higher current capacity or extended operating temperature ranges.

Substiute Parts

KSA708YBU

onsemiIn Stock: 91107KSA708YBU Datasheet

Current PartRFQ

PN2907A PBFREE

Central Semiconductor CorpIn Stock: 11246PN2907A PBFREE Datasheet

SimilarRFQ

ZTX551STZ

Diodes IncorporatedIn Stock: 29251ZTX551STZ Datasheet

SimilarRFQ

KSA708YBU

Fairchild SemiconductorIn Stock: 91057KSA708YBU Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the KSA708YBU is determined by strict adherence to the following electrical and mechanical parameters:

Critical Matching Parameters:

• Transistor Type: PNP configuration
• Voltage - Collector Emitter Breakdown (Max): 60V minimum
• Mounting Type: Through Hole
• Package Compatibility: TO-92-3 or TO-92 compatible form factors

Allowable Variation Parameters:

• Current - Collector (Ic) (Max): Equal to or greater than 700mA
• Power - Max: Equal to or greater than 800mW
• Frequency - Transition: Equal to or greater than 50MHz
• Operating Temperature Range: Must accommodate application requirements
• DC Current Gain (hFE): Minimum specifications must be met for circuit function

Substitute parts are grouped into two categories: direct equivalents with identical electrical specifications across manufacturers, and functional substitutes with equal or superior electrical performance that maintain circuit compatibility.

Parameter Comparison

Engineering Selection Recommendations

KSA708YBU (Fairchild Semiconductor): This part is a parametric equivalent to the onsemi KSA708YBU, offering identical electrical specifications and TO-92-3 package configuration. Selection of this variant is appropriate when Fairchild Semiconductor sourcing is preferred or when supply from onsemi is constrained. RoHS compliance status should be verified with the supplier prior to procurement for applications requiring regulatory documentation.

PN2907A PBFREE (Central Semiconductor Corp): This substitute operates at 60V collector-emitter breakdown voltage with 600mA maximum collector current, representing a 14% reduction in current capacity compared to the KSA708YBU. The PN2907A PBFREE provides superior frequency performance at 200MHz transition frequency and maintains TO-92-3 package compatibility. This part is suitable for applications where the 600mA current specification is sufficient and where higher frequency operation provides circuit performance benefits. RoHS3 compliance and MSL 1 rating support modern manufacturing environments.

ZTX551STZ (Diodes Incorporated): This substitute provides enhanced electrical performance with 1A maximum collector current (43% higher than KSA708YBU), 1W maximum power dissipation (25% higher), and 150MHz transition frequency. The ZTX551STZ operates across an extended temperature range of -55°C to 200°C, providing 50°C additional high-temperature capability. The E-Line package maintains TO-92 form factor compatibility with mechanical lead forming. This part is selected for applications requiring higher current capacity, increased power handling, or extended operating temperature specifications. RoHS3 compliance and MSL 1 rating are confirmed.

All substitute parts maintain PNP transistor configuration, 60V collector-emitter breakdown voltage, and Through Hole mounting type, ensuring mechanical and electrical compatibility within the specified parameter envelope.

Frequently Asked Questions (FAQ)

Q: Can the PN2907A PBFREE be used as a direct replacement for the KSA708YBU in all applications?

A: The PN2907A PBFREE operates at 600mA maximum collector current, which is 100mA lower than the KSA708YBU specification of 700mA. Direct substitution is valid only when circuit design current requirements do not exceed 600mA. Both parts maintain 60V collector-emitter breakdown voltage and TO-92-3 package compatibility. Verify circuit current specifications before substitution.

Q: What are the advantages of selecting the ZTX551STZ over the KSA708YBU?

A: The ZTX551STZ provides three primary advantages: increased collector current capacity of 1A (versus 700mA), increased power dissipation capability of 1W (versus 800mW), and extended maximum operating temperature of 200°C (versus 150°C). The ZTX551STZ also offers 150MHz transition frequency, exceeding the KSA708YBU specification of 50MHz. These enhancements support applications with higher current demands or elevated thermal environments. The E-Line package maintains TO-92 form factor compatibility.

Q: Are all substitute parts RoHS3 compliant?

A: The PN2907A PBFREE and ZTX551STZ are confirmed RoHS3 compliant. The Fairchild Semiconductor KSA708YBU RoHS compliance status is not specified in the provided documentation and should be verified with the supplier. The onsemi KSA708YBU is confirmed RoHS3 compliant.

Q: What is the significance of the E-Line package designation for the ZTX551STZ?

A: The ZTX551STZ utilizes an E-Line package with formed leads that is mechanically compatible with TO-92 footprints. This package designation indicates the device features formed lead geometry rather than the standard straight-lead TO-92-3 configuration. The E-Line package maintains electrical and mechanical compatibility with standard TO-92 circuit board layouts and component handling equipment.

Q: Can the KSA708YBU (Fairchild Semiconductor) be used interchangeably with the KSA708YBU (onsemi)?

A: Yes. Both parts share identical part number designation and electrical specifications, including 700mA collector current, 60V collector-emitter breakdown voltage, 800mW power dissipation, and TO-92-3 package configuration. These are parametric equivalents from different manufacturers. Verify RoHS compliance documentation with the Fairchild Semiconductor supplier for regulatory requirements.

Q: What factors should determine selection between the three substitute options?

A: Selection criteria are based on application-specific requirements: (1) Current capacity: PN2907A PBFREE for applications requiring 600mA or less; KSA708YBU variants for 700mA; ZTX551STZ for 1A applications. (2) Frequency performance: PN2907A PBFREE for 200MHz applications; ZTX551STZ for 150MHz; KSA708YBU variants for 50MHz. (3) Operating temperature: ZTX551STZ for environments exceeding 150°C up to 200°C. (4) Supply chain availability: Fairchild Semiconductor variant when onsemi sourcing is unavailable. (5) Packaging preference: E-Line for ZTX551STZ; TO-92-3 for all other options.

Q: Is the PN2907A PBFREE suitable for high-frequency applications?

A: Yes. The PN2907A PBFREE provides 200MHz transition frequency, which exceeds both the KSA708YBU (50MHz) and ZTX551STZ (150MHz) specifications. This part is appropriate for applications requiring high-frequency switching or amplification performance. However, the 600mA maximum collector current specification must be verified against circuit requirements.