KSC1845PBU Equivalent & Substitute Parts

Part Overview

The KSC1845PBU is an NPN bipolar junction transistor manufactured by onsemi, rated for 120 V collector-emitter breakdown voltage and 50 mA maximum collector current. This device is packaged in a TO-92-3 through-hole configuration and is designed for general-purpose switching and amplification applications requiring 500 mW power dissipation capability.

The KSC1845PBU carries an obsolete product status. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production and repair requirements for legacy systems utilizing this component.

Substiute Parts

KSC1845PBU

onsemiIn Stock: 767KSC1845PBU Datasheet

Current PartRFQ

KSC1845FTA

onsemiIn Stock: 31820KSC1845FTA Datasheet

SimilarRFQ

2SC1841-A

NEC CorporationIn Stock: 744872SC1841-A Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the KSC1845PBU is determined by strict equivalence across the following critical parameters:

• Transistor Type: NPN configuration required
• Current Rating: 50 mA maximum collector current
• Voltage Rating: 120 V collector-emitter breakdown voltage
• Saturation Characteristics: 300 mV Vce saturation at specified base and collector currents
• Power Dissipation: 500 mW maximum
• Frequency Response: 110 MHz transition frequency
• Package: TO-92-3 through-hole configuration
• Mounting: Through-hole technology

Substitute parts must maintain electrical equivalence across all specified parameters. Packaging format variations (such as cut tape versus bulk) do not affect functional substitution. DC current gain (hFE) variations within the specified minimum threshold do not preclude substitution, provided all other parameters remain equivalent.

Parameter Comparison

Engineering Selection Recommendations

KSC1845FTA is the primary substitute for the obsolete KSC1845PBU. Both devices are manufactured by onsemi and maintain identical electrical specifications across all critical parameters. The KSC1845FTA carries active product status, ensuring ongoing availability and supply chain support. The device is supplied in cut tape packaging format and is ROHS3 compliant. The higher DC current gain (hFE minimum of 300 versus 200) provides improved performance margin without compromising compatibility.

2SC1841-A is a parametric equivalent manufactured by NEC Corporation. This device maintains electrical equivalence across all primary specifications including collector current, voltage rating, saturation characteristics, power dissipation, and frequency response. The 2SC1841-A carries active product status and ROHS3 compliance. The operating temperature maximum is specified at 125°C compared to 150°C for the KSC1845PBU, representing a reduced thermal operating range. This device is supplied in bulk packaging format.

For new designs and ongoing production requiring the highest supply availability and compliance assurance, the KSC1845FTA is the preferred selection. The 2SC1841-A is suitable for applications where the reduced maximum operating temperature does not present a constraint.

Frequently Asked Questions (FAQ)

Q: Can the KSC1845FTA directly replace the KSC1845PBU in existing circuit designs?

A: Yes. The KSC1845FTA maintains complete electrical equivalence with the KSC1845PBU across all specified parameters including collector current, voltage rating, saturation characteristics, power dissipation, and frequency response. Both devices utilize identical TO-92-3 through-hole packaging. The packaging format difference (cut tape versus standard packaging) does not affect functional compatibility.

Q: What is the significance of the higher DC current gain (hFE) in the KSC1845FTA?

A: The KSC1845FTA specifies a minimum DC current gain of 300 at 1 mA and 6 V, compared to 200 for the KSC1845PBU. This represents improved current amplification capability. Since the specified minimum is higher, the KSC1845FTA will deliver equal or superior performance in applications requiring base current drive. This does not create incompatibility; it provides additional performance margin.

Q: Is the 2SC1841-A suitable as a substitute for the KSC1845PBU?

A: Yes. The 2SC1841-A is a parametric equivalent that maintains electrical equivalence across all critical specifications. The device is manufactured by NEC Corporation and carries active product status. The maximum operating temperature is specified at 125°C compared to 150°C for the KSC1845PBU. Applications operating within the 125°C thermal envelope will experience no functional difference.

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

A: The KSC1845FTA is supplied in cut tape (CT) format. The 2SC1841-A is supplied in bulk format. Both devices are housed in TO-92-3 through-hole packages with identical pin configurations and mechanical dimensions. Packaging format selection depends on assembly process requirements and procurement volume.

Q: Are the substitute parts RoHS compliant?

A: The KSC1845FTA and 2SC1841-A are both ROHS3 compliant. The original KSC1845PBU carries REACH Unaffected status. Both substitute parts meet current environmental and regulatory compliance requirements for electronic component manufacturing and distribution.

Q: Can these parts be used interchangeably in production?

A: The KSC1845FTA and 2SC1841-A maintain electrical equivalence and can be used interchangeably provided circuit design parameters remain within the specified operating ranges of both devices. The reduced maximum operating temperature of the 2SC1841-A (125°C versus 150°C) must be evaluated against application thermal requirements. Both devices are suitable for through-hole assembly processes without modification to PCB layouts or assembly procedures.