SI3420-TP N-Channel MOSFET 20V 6A Equivalent & Substitute Parts

Part Overview

The SI3420-TP is an N-Channel MOSFET manufactured by Micro Commercial Co, rated for 20V drain-to-source voltage with 6A continuous drain current at 25°C. This device is housed in a SOT-23 surface mount package and is designed for general-purpose switching applications requiring compact form factors. The part is Active in product status with full RoHS3 compliance and REACH unaffected designation. Equivalent and substitute parts are identified based on matching electrical specifications, package compatibility, and thermal performance characteristics within the defined parameter ranges.

Substiute Parts

SI3420-TP

Micro Commercial CoIn Stock: 930SI3420-TP Datasheet

Current PartRFQ

FDN028N20

onsemiIn Stock: 11654FDN028N20 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the SI3420-TP is determined by electrical and mechanical parameter compatibility within the following criteria:

Electrical Compatibility Requirements:

• Drain-to-Source Voltage (Vdss) must equal or exceed 20V
• Continuous Drain Current (Id) must equal or exceed 6A at 25°C
• On-Resistance (Rds On) must not exceed the specified maximum at rated conditions
• Gate-Source Threshold Voltage (Vgs(th)) must be compatible with drive circuit requirements
• Maximum Gate-Source Voltage (Vgs Max) must equal or exceed ±12V
• Operating temperature range must encompass -55°C to 150°C

Mechanical Compatibility Requirements:

• Package type must be SOT-23-3 (TO-236-3, SC-59 equivalent)
• Surface mount configuration required
• Pin configuration must match SOT-23-3 standard

Compliance Requirements:

• RoHS3 compliance required
• REACH unaffected status required
• Active product status preferred for long-term availability

The FDN028N20 meets all electrical and mechanical substitution criteria for the SI3420-TP.

Parameter Comparison

Engineering Selection Recommendations

The FDN028N20 manufactured by onsemi is a qualified substitute for the SI3420-TP. Both devices are Active in product status, ensuring continued availability and support. Both parts maintain full RoHS3 compliance and REACH unaffected status, meeting regulatory requirements for industrial and commercial applications.

The FDN028N20 provides equivalent or superior electrical performance across all critical parameters. The substitute device delivers 6.1A continuous drain current, exceeding the 6A requirement of the main part. On-resistance specifications are comparable, with the FDN028N20 rated at 28 mOhm versus 24 mOhm for the SI3420-TP. The lower gate-source threshold voltage (1.5V versus 3V) of the substitute part may require verification in drive circuit applications to ensure compatibility with existing gate drive voltage levels.

Both devices operate across the identical temperature range of -55°C to 150°C and are packaged in SOT-23-3 surface mount configuration, enabling direct mechanical substitution. The FDN028N20 offers enhanced power dissipation capability at 1.5W compared to 350 mW for the SI3420-TP, providing additional thermal margin in applications with elevated power requirements.

Frequently Asked Questions (FAQ)

Q: Can the FDN028N20 be used as a direct replacement for the SI3420-TP in existing PCB designs?

A: Yes. Both devices are packaged in SOT-23-3 surface mount configuration with identical pin assignments. No PCB layout modifications are required for mechanical substitution. Gate drive circuit compatibility must be verified due to the lower threshold voltage of the FDN028N20 (1.5V versus 3V).

Q: What are the key electrical differences between these two parts?

A: The FDN028N20 provides higher continuous drain current (6.1A versus 6A) and superior power dissipation capability (1.5W versus 350 mW). The substitute part features a lower gate-source threshold voltage (1.5V versus 3V) and slightly lower input capacitance (600 pF versus 630 pF). On-resistance values are comparable within acceptable engineering tolerances.

Q: Are both parts compliant with current regulatory standards?

A: Yes. Both the SI3420-TP and FDN028N20 are RoHS3 compliant and REACH unaffected. Both devices maintain Active product status with established supply chains.

Q: Does the lower threshold voltage of the FDN028N20 affect circuit operation?

A: The lower threshold voltage (1.5V) of the FDN028N20 compared to the SI3420-TP (3V) means the substitute device requires less gate voltage to initiate conduction. This characteristic must be evaluated within the context of the specific gate drive circuit to ensure proper switching behavior and prevent unintended device activation.

Q: What is the packaging difference between the two parts?

A: Both devices use SOT-23-3 surface mount packaging. The SI3420-TP is supplied in Tape & Reel format, while the FDN028N20 is available in Cut Tape and Digi-Reel® formats. All formats are compatible with standard surface mount assembly equipment.

Q: Can the FDN028N20 handle higher power dissipation than the SI3420-TP?

A: Yes. The FDN028N20 is rated for 1.5W maximum power dissipation compared to 350 mW for the SI3420-TP. This provides additional thermal headroom in applications where power dissipation approaches device limits.