FDS4435 P-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The FDS4435 is a P-Channel MOSFET manufactured by onsemi, rated for 30V drain-to-source voltage with 8.8A continuous drain current at 25°C. The device is housed in an 8-SOIC surface mount package and features a maximum on-resistance of 20mOhm at 8.8A and 10V gate-source voltage. The FDS4435 is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production support. Alternative devices with matching or superior electrical characteristics are available from multiple manufacturers in compatible package configurations.

Substiute Parts

FDS4435

onsemiIn Stock: 22253FDS4435 Datasheet

Current PartRFQ

FDS4435BZ

onsemiIn Stock: 68203FDS4435BZ Datasheet

DirectRFQ

SI4435DY

onsemiIn Stock: 2765SI4435DY Datasheet

Parametric EquivalentRFQ

AO4407A

Alpha & Omega Semiconductor Inc.In Stock: 150425AO4407A Datasheet

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AO4419

Alpha & Omega Semiconductor Inc.In Stock: 150171AO4419 Datasheet

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DMP3036SSS-13

Diodes IncorporatedIn Stock: 1338DMP3036SSS-13 Datasheet

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RS3E075ATTB

Rohm SemiconductorIn Stock: 11487RS3E075ATTB Datasheet

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RSS075P03TB

Rohm SemiconductorIn Stock: 19894RSS075P03TB Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FDS4435 are classified based on electrical parameter compatibility and product status. The primary substitution criteria are:

Critical Parameters for Substitution:

• Drain-to-Source Voltage (Vdss): Must equal or exceed 30V
• FET Type: Must be P-Channel
• Package: Must be 8-SOIC or mechanically equivalent
• On-Resistance (Rds On): Should not exceed 20mOhm at rated conditions to maintain thermal performance
• Continuous Drain Current (Id): Must support minimum 8.8A operation
• Operating Temperature: Must support the application's thermal requirements

Direct Manufacturer Equivalent: FDS4435BZ is the active production variant of the FDS4435, manufactured by onsemi with identical electrical specifications and the same PowerTrench® series designation. This part differs only in packaging format (Cut Tape & Digi-Reel®) and product status (Active).

Parametric Equivalents: SI4435DY (onsemi) matches all critical electrical parameters of the FDS4435, including Vdss, Id, Rds On, and gate charge characteristics. Minor differences exist in maximum gate-source voltage (±20V vs. ±25V) and operating temperature range (175°C vs. 150°C maximum junction temperature).

Similar Alternatives: AO4407A, AO4419, DMP3036SSS-13, RS3E075ATTB, and RSS075P03TB provide functional substitution with variations in current rating, on-resistance, or power dissipation. These parts maintain the 30V Vdss rating and 8-SOIC package but offer different performance characteristics suited to specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Recommended for New Designs):

FDS4435BZ is the primary recommended substitute. As an active production part from onsemi with identical electrical specifications and the same PowerTrench® series technology, it provides seamless functional replacement. The part is ROHS3 compliant and available in higher quantities (68,168 pcs in stock). The only design consideration is the reduced maximum operating temperature (150°C vs. 175°C junction temperature), which is acceptable for most applications operating below 150°C.

For Parametric Equivalence:

SI4435DY (onsemi) maintains all critical electrical parameters matching the FDS4435, including on-resistance, gate charge, and input capacitance. This part is active and ROHS3 compliant. The maximum gate-source voltage is reduced to ±20V (from ±25V), and the operating temperature range is -55°C to 175°C. Selection of SI4435DY is appropriate when the ±20V gate voltage specification is compatible with the application.

For Enhanced Performance (Higher Current or Lower On-Resistance):

AO4407A provides 12A continuous drain current with 11mOhm on-resistance, offering improved current handling and reduced conduction losses. However, this part is marked "Not For New Designs" and has a reduced operating temperature range (-55°C to 150°C). AO4419 is an active alternative from Alpha & Omega with 9.7A current rating and 20mOhm on-resistance, suitable for applications requiring active product support.

For High Current Applications:

DMP3036SSS-13 (Diodes Incorporated) supports 19.5A continuous drain current with 20mOhm on-resistance and is active and ROHS3 compliant. This part is suitable for applications requiring higher current capacity than the FDS4435 baseline.

For Thermal-Constrained Applications:

RSS075P03TB (Rohm) is an active part with 7.5A current rating and 2W power dissipation, suitable for applications with limited thermal headroom. This part maintains the 30V Vdss rating and 8-SOIC package footprint.

Frequently Asked Questions (FAQ)

Q: Can FDS4435BZ be used as a direct replacement for FDS4435?

A: Yes. FDS4435BZ is the active production equivalent manufactured by onsemi with identical electrical specifications (30V Vdss, 8.8A Id, 20mOhm Rds On). The primary difference is product status (Active vs. Obsolete) and packaging format. The maximum operating temperature is reduced from 175°C to 150°C, which is acceptable for most applications.

Q: What is the difference between SI4435DY and FDS4435?

A: SI4435DY matches the FDS4435 in all critical electrical parameters: 30V Vdss, 8.8A continuous drain current, and 20mOhm on-resistance. Both are onsemi PowerTrench® devices. SI4435DY has a reduced maximum gate-source voltage (±20V vs. ±25V) and identical operating temperature range (-55°C to 175°C). SI4435DY is active and ROHS3 compliant.

Q: Can I use AO4407A as a substitute for FDS4435?

A: AO4407A provides functional substitution with enhanced specifications: 12A continuous drain current (vs. 8.8A) and 11mOhm on-resistance (vs. 20mOhm). However, AO4407A is marked "Not For New Designs" and has a reduced operating temperature range (-55°C to 150°C). Use this part only for legacy system support or when higher current capacity is required and product lifecycle status is acceptable.

Q: Are all substitute parts available in the same 8-SOIC package?

A: Most substitutes use 8-SOIC or mechanically equivalent packages (8-SO, 8-SOP, 8-SOP-J). These packages are physically compatible with standard 8-SOIC footprints. Verify PCB layout compatibility before final selection, particularly for high-current applications where thermal management via PCB copper area is critical.

Q: What is the impact of reduced maximum gate-source voltage in SI4435DY?

A: SI4435DY has a maximum gate-source voltage of ±20V compared to ±25V for FDS4435. This is acceptable for applications using standard gate drive voltages (typically ±10V to ±15V). Applications requiring gate voltages exceeding ±20V must use FDS4435BZ or other parts with ±25V rating.

Q: Which substitute offers the best thermal performance?

A: DMP3036SSS-13 offers the lowest power dissipation (1.4W Ta) and highest current capacity (19.5A), providing superior thermal performance. However, this part is suitable only for applications where the higher current rating does not introduce design complications. For direct thermal improvement with minimal design changes, AO4407A provides 3.1W power dissipation and lower on-resistance (11mOhm).

Q: Are all substitute parts RoHS3 compliant?

A: All active substitute parts listed (FDS4435BZ, SI4435DY, AO4419, DMP3036SSS-13, RSS075P03TB) are ROHS3 compliant. Parts marked "Not For New Designs" (AO4407A, RS3E075ATTB) are also ROHS3 compliant but should not be selected for new designs unless legacy support is required.

Q: What inventory considerations should I evaluate?

A: FDS4435BZ has the highest inventory (68,168 pcs), followed by AO4407A (150,400 pcs) and AO4419 (150,100 pcs). SI4435DY has lower inventory (2,716 pcs). For production programs requiring sustained supply, FDS4435BZ is the recommended choice due to both active status and high inventory levels.