BSS123W N-Channel MOSFET 100V 170mA Equivalent & Substitute Parts

Part Overview

The BSS123W is an N-Channel enhancement-mode MOSFET manufactured by onsemi, rated for 100V drain-to-source voltage with 170mA continuous drain current at 25°C. The device is packaged in SOT-323 (SC-70) surface mount configuration and dissipates a maximum of 200mW. The BSS123W is classified as obsolete, necessitating identification of active equivalent and substitute components for new designs and production continuity. Substitute parts must maintain electrical compatibility across voltage ratings, current handling, on-resistance characteristics, and thermal specifications while meeting RoHS3 compliance and MSL-1 moisture sensitivity requirements.

Substiute Parts

BSS123W

onsemiIn Stock: 7970BSS123W Datasheet

Current PartRFQ

BSS123W-7-F

Diodes IncorporatedIn Stock: 185371BSS123W-7-F Datasheet

UpgradeRFQ

BSS123WQ-7-F

Diodes IncorporatedIn Stock: 50382BSS123WQ-7-F Datasheet

UpgradeRFQ

BSS123W RFG

Taiwan Semiconductor CorporationIn Stock: 5488BSS123W RFG Datasheet

SimilarRFQ

PJC7476_R1_00001

Panjit International Inc.In Stock: 6043PJC7476_R1_00001 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BSS123W are classified into two categories based on electrical parameter alignment:

Upgrade Substitutes (Direct Equivalents): Parts BSS123W-7-F and BSS123WQ-7-F, both manufactured by Diodes Incorporated, maintain identical electrical specifications to the original BSS123W across all critical parameters: 100V Vdss, 170mA Id, 6Ohm Rds On @ 170mA/10V, 2V Vgs(th), and ±20V Vgs range. These parts are classified as active products with full RoHS3 compliance and MSL-1 rating. The primary distinction between these upgrade substitutes is packaging format: BSS123W-7-F is supplied in Cut Tape (CT) & Digi-Reel format, while BSS123WQ-7-F is supplied in Tape & Reel (TR) format. Input capacitance (Ciss) is reduced to 60pF @ 25V compared to the original 71pF, representing a minor performance improvement.

Similar Substitutes (Parameter Variants): Parts BSS123W RFG (Taiwan Semiconductor Corporation) and PJC7476_R1_00001 (Panjit International Inc.) maintain the 100V Vdss rating and SOT-323 package but exhibit variations in continuous drain current, on-resistance, and power dissipation. These parts are active products with RoHS3 compliance and MSL-1 rating. BSS123W RFG supports 160mA Id with 5Ohm Rds On and 298mW power dissipation. PJC7476_R1_00001 supports 300mA Id with 6Ohm Rds On and 350mW power dissipation. Similar substitutes are suitable for applications where the original 170mA current rating is not a limiting constraint and where the higher power dissipation capability of PJC7476_R1_00001 provides design margin.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Preferred): Select BSS123W-7-F or BSS123WQ-7-F from Diodes Incorporated. Both parts are active products with identical electrical specifications to the obsolete BSS123W, ensuring pin-for-pin and functional compatibility. Choose BSS123W-7-F for applications requiring Cut Tape or Digi-Reel packaging formats. Choose BSS123WQ-7-F for applications requiring Tape & Reel packaging. Both parts carry ROHS3 compliance and MSL-1 moisture sensitivity rating, meeting regulatory and supply chain requirements. The reduced input capacitance (60pF vs. 71pF) provides a minor performance advantage in switching applications.

For Current-Limited Applications: Select BSS123W RFG from Taiwan Semiconductor Corporation when the application current requirement is 160mA or less. This part maintains 100V Vdss rating and SOT-323 packaging with active product status and full compliance certifications. The 5Ohm on-resistance provides improved efficiency compared to the 6Ohm specification of the original part.

For High-Power Margin Applications: Select PJC7476_R1_00001 from Panjit International Inc. when the application requires higher current handling (300mA) or increased power dissipation margin (350mW vs. 200mW). This part maintains 100V Vdss rating and SOT-323 packaging with active product status and full compliance certifications. The higher current rating and power dissipation capability provide design flexibility for applications with variable or peak current demands.

All substitute parts maintain the SOT-323 (SC-70) surface mount package, enabling direct PCB layout compatibility without redesign. All parts are RoHS3 compliant and carry MSL-1 moisture sensitivity rating, ensuring compatibility with standard manufacturing and storage processes.

Frequently Asked Questions (FAQ)

Q: Can BSS123W-7-F or BSS123WQ-7-F be used as direct replacements for the obsolete BSS123W?

A: Yes. Both BSS123W-7-F and BSS123WQ-7-F are direct electrical equivalents to the BSS123W. They maintain identical specifications for Vdss (100V), Id (170mA), Rds On (6Ohm @ 170mA/10V), Vgs(th) (2V @ 1mA), and operating temperature range (-55°C to 150°C). Both are active products with ROHS3 compliance and MSL-1 rating. The only difference is packaging format: Cut Tape/Digi-Reel versus Tape & Reel.

Q: What is the difference between the upgrade substitutes (BSS123W-7-F, BSS123WQ-7-F) and similar substitutes (BSS123W RFG, PJC7476_R1_00001)?

A: Upgrade substitutes maintain identical electrical specifications to the original BSS123W across all critical parameters. Similar substitutes maintain the 100V Vdss rating and SOT-323 package but vary in continuous drain current and power dissipation. BSS123W RFG supports 160mA (vs. 170mA) with 298mW power dissipation. PJC7476_R1_00001 supports 300mA with 350mW power dissipation. Similar substitutes are suitable when the original 170mA rating is not a constraint.

Q: Are all substitute parts compatible with the original PCB layout?

A: Yes. All substitute parts use the SOT-323 (SC-70) surface mount package with identical pin configuration and footprint to the BSS123W. No PCB redesign is required for any of the listed substitutes.

Q: Do all substitute parts meet RoHS3 and MSL-1 requirements?

A: Yes. All substitute parts listed carry ROHS3 compliance and MSL-1 (Unlimited) moisture sensitivity rating, matching the original BSS123W specifications. All parts are suitable for standard manufacturing and storage processes without special handling.

Q: What is the significance of the reduced input capacitance (Ciss) in BSS123W-7-F and BSS123WQ-7-F?

A: The input capacitance is reduced from 71pF (original) to 60pF in the Diodes Incorporated parts. This reduction improves switching speed and reduces gate drive power requirements in high-frequency applications, providing a minor performance advantage without affecting DC electrical specifications.

Q: Which substitute should be selected for a new design?

A: For new designs, select BSS123W-7-F or BSS123WQ-7-F from Diodes Incorporated. These parts are active products with identical electrical specifications, full compliance certifications, and superior availability compared to the obsolete original. Choose the packaging format (Cut Tape or Tape & Reel) based on manufacturing requirements.

Q: Can PJC7476_R1_00001 be used in applications designed for 170mA operation?

A: Yes. PJC7476_R1_00001 supports 300mA continuous drain current, which exceeds the 170mA requirement of the original BSS123W. The part maintains 100V Vdss rating, 6Ohm on-resistance, and SOT-323 packaging. The higher current rating and power dissipation (350mW) provide design margin for applications with variable or peak current demands.

Q: What is the impact of different Vgs(th) specifications between parts?

A: The original BSS123W and Diodes Incorporated substitutes specify Vgs(th) Max of 2V @ 1mA. BSS123W RFG and PJC7476_R1_00001 specify Vgs(th) Max of 2.5V @ 250µA. The higher threshold voltage in similar substitutes may require slightly higher gate drive voltage for full on-state operation but remains within the ±20V Vgs maximum rating. This difference is not significant for standard gate drive circuits operating at 5V or 10V.