AO4415 Equivalent & Substitute Parts

Part Overview

The AO4415 is a P-Channel MOSFET manufactured by Alpha & Omega Semiconductor Inc., rated for 30V drain-to-source voltage with 8A continuous drain current in an 8-SOIC surface mount package. This device is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The AO4415 operates across a temperature range of -55°C to 150°C and dissipates a maximum of 3W at ambient temperature.

Substiute Parts

AO4415

Alpha & Omega Semiconductor Inc.In Stock: 21159AO4415 Datasheet

Current PartRFQ

FDS4435BZ

onsemiIn Stock: 68203FDS4435BZ Datasheet

DirectRFQ

SI4435DDY-T1-GE3

Vishay SiliconixIn Stock: 105334SI4435DDY-T1-GE3 Datasheet

MFR RecommendedRFQ

SI4435DY

onsemiIn Stock: 2765SI4435DY Datasheet

MFR RecommendedRFQ

STS6P3LLH6

STMicroelectronicsIn Stock: 6392STS6P3LLH6 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AO4415 is determined by strict adherence to the following electrical and mechanical parameters:

Critical Matching Parameters:

• FET Type: P-Channel (required)
• Drain to Source Voltage (Vdss): 30V (required)
• Package Type: 8-SOIC (required)
• Mounting Type: Surface Mount (required)
• Operating Temperature Range: Minimum -55°C to 150°C (required)

Performance Parameters (allowable variation):

• Continuous Drain Current (Id): Minimum 8A at 25°C
• Rds On (Max): Not to exceed 26 mOhm at rated current and gate voltage
• Gate Threshold Voltage (Vgs(th)): Maximum 3.5V at 250µA
• Gate Charge (Qg): Maximum 21 nC at 10V
• Input Capacitance (Ciss): Maximum 1100 pF at 15V
• Power Dissipation: Minimum 3W at ambient temperature

All substitute parts listed meet or exceed these parameters while maintaining identical package and mounting specifications.

Parameter Comparison

Engineering Selection Recommendations

FDS4435BZ (onsemi PowerTrench®)

The FDS4435BZ is an active production substitute with equivalent drain current (8.8A) and superior on-resistance characteristics (20 mOhm vs. 26 mOhm). This device maintains the 30V Vdss rating and 8-SOIC package compatibility. The FDS4435BZ is ROHS3 compliant and carries active product status, ensuring long-term availability and supply chain stability. Gate charge is elevated at 40 nC, which may impact switching speed in high-frequency applications.

SI4435DDY-T1-GE3 (Vishay Siliconix TrenchFET®)

The SI4435DDY-T1-GE3 offers the highest drain current rating (11.4A at Tc) among available substitutes, providing design margin for thermal management. On-resistance is 24 mOhm at 9.1A, meeting the AO4415 specification. This device is ROHS3 compliant with active product status. Gate charge is 50 nC at 10V, the highest among substitutes. Maximum gate voltage is ±20V, which is 5V lower than the AO4415 specification of ±25V.

SI4435DY (onsemi PowerTrench®)

The SI4435DY provides equivalent drain current (8.8A) and on-resistance (20 mOhm) to the FDS4435BZ. This device extends the operating temperature range to -55°C to 175°C, exceeding the AO4415 specification. ROHS3 compliance and active product status are confirmed. Gate charge is 24 nC at 5V, lower than the AO4415 at 21 nC at 10V. Maximum gate voltage is ±20V.

STS6P3LLH6 (STMicroelectronics DeepGATE™/STripFET™ VI)

The STS6P3LLH6 is suitable for applications where drain current requirements are lower than the AO4415 specification. Continuous drain current is rated at 6A, below the 8A requirement. Gate charge is the lowest among substitutes at 12 nC at 4.5V, advantageous for switching speed optimization. On-resistance is 30 mOhm at 3A, exceeding the AO4415 specification. ROHS3 compliance and active product status are confirmed. Operating temperature specification lists only 150°C (TJ) without explicit lower bound.

Frequently Asked Questions (FAQ)

Q: Can the FDS4435BZ directly replace the AO4415 in existing designs?

A: The FDS4435BZ is mechanically and electrically compatible with the AO4415. Both devices are P-Channel MOSFETs in 8-SOIC packages rated for 30V Vdss. The FDS4435BZ provides superior on-resistance (20 mOhm vs. 26 mOhm) and higher drain current (8.8A vs. 8A), making it suitable for direct substitution. Gate charge is higher at 40 nC, which may affect switching characteristics in high-frequency circuits.

Q: What is the primary difference between SI4435DDY-T1-GE3 and SI4435DY?

A: Both devices are onsemi PowerTrench® MOSFETs with identical electrical ratings (8.8A, 20 mOhm on-resistance, 30V Vdss). The SI4435DDY-T1-GE3 is manufactured by Vishay Siliconix under the TrenchFET® series and offers higher drain current (11.4A at Tc). The SI4435DY extends the operating temperature range to 175°C. Packaging differs: SI4435DDY-T1-GE3 is supplied in Cut Tape & Digi-Reel®, while SI4435DY is supplied in Tape & Reel (TR).

Q: Is the STS6P3LLH6 suitable for all AO4415 applications?

A: The STS6P3LLH6 is not universally suitable as a direct replacement. The continuous drain current rating is 6A, which is 2A below the AO4415 specification of 8A. This device is appropriate only for applications where the actual drain current requirement does not exceed 6A. On-resistance is also higher at 30 mOhm compared to 26 mOhm for the AO4415.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. The FDS4435BZ, SI4435DDY-T1-GE3, SI4435DY, and STS6P3LLH6 are all ROHS3 compliant. The AO4415 does not specify RoHS status due to its obsolete classification.

Q: What is the impact of higher gate charge on circuit performance?

A: Gate charge (Qg) determines the energy required to switch the MOSFET on and off. Higher gate charge increases switching time and power dissipation in the gate driver circuit. The AO4415 specifies 21 nC at 10V. The FDS4435BZ (40 nC) and SI4435DDY-T1-GE3 (50 nC) require more gate charge, potentially increasing driver power consumption. The STS6P3LLH6 (12 nC) and SI4435DY (24 nC) are comparable or lower.

Q: Can I use a substitute with lower maximum gate voltage (±20V vs. ±25V)?

A: Substitutes with ±20V maximum gate voltage (SI4435DDY-T1-GE3, SI4435DY, STS6P3LLH6) are compatible with designs using gate voltages up to ±20V. If the existing design applies gate voltages exceeding ±20V, these substitutes are not suitable. The FDS4435BZ does not specify maximum gate voltage in the provided data.

Q: What is the significance of the 8-SOIC package specification?

A: The 8-SOIC package is a surface mount integrated circuit package with 8 pins, measuring 0.154 inches (3.90 mm) in width. All substitute parts use identical 8-SOIC packaging, ensuring mechanical compatibility with existing PCB layouts, solder reflow processes, and automated assembly equipment. No PCB redesign is required for package compatibility.

Q: Which substitute offers the best thermal performance?

A: The SI4435DDY-T1-GE3 offers the highest power dissipation rating at 5W (Tc), compared to 3W (Ta) for the AO4415. This device also provides the highest drain current (11.4A at Tc), allowing better thermal margin in high-current applications. The FDS4435BZ, SI4435DY, and STS6P3LLH6 are rated at 2.5W to 2.7W, below the AO4415 specification.

Q: Are there inventory considerations for substitute selection?

A: Inventory levels vary significantly among substitutes. The SI4435DDY-T1-GE3 has the highest inventory (105,300 pcs), followed by FDS4435BZ (68,168 pcs). The SI4435DY has lower inventory (2,716 pcs), and STS6P3LLH6 has 6,367 pcs. For high-volume production, the SI4435DDY-T1-GE3 or FDS4435BZ are preferred for supply chain reliability.