FDS6689S N-Channel 30V 16A MOSFET Equivalent & Substitute Parts

Part Overview

The FDS6689S is an N-Channel MOSFET manufactured by onsemi, rated for 30V drain-to-source voltage with 16A continuous drain current at 25°C. The device is housed in an 8-SOIC surface mount package and dissipates a maximum of 2.5W at ambient temperature. This part is classified as obsolete, making identification of equivalent and substitute components necessary for ongoing design support, production continuity, and system maintenance.

Key Parameters

Parameter	Value	Unit
FET Type	N-Channel	—
Drain-to-Source Voltage (Vdss)	30	V
Continuous Drain Current (Id) @ 25°C	16	A (Ta)
On-Resistance (Rds On) @ 16A, 10V	5.4	mOhm
Gate Threshold Voltage (Vgs(th)) @ 1mA	3	V
Gate Charge (Qg) @ 10V	78	nC
Input Capacitance (Ciss) @ 15V	3290	pF
Power Dissipation (Max)	2.5	W (Ta)
Operating Temperature Range	−55 to 150	°C (TJ)
Mounting Type	Surface Mount	—
Package	8-SOIC	—
Moisture Sensitivity Level	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution of the FDS6689S is determined by strict alignment of electrical and mechanical parameters. The following criteria establish compatibility:

Primary Substitution Criteria:

FET Type: N-Channel (required)
Drain-to-Source Voltage (Vdss): 30V (required)
Continuous Drain Current (Id): 16A minimum at 25°C (required)
Package: 8-SOIC or equivalent 8-pin surface mount (required)
Operating Temperature Range: −55°C to 150°C (required)
Gate-to-Source Voltage (Vgs): ±20V (required)

Secondary Compatibility Parameters:

On-Resistance (Rds On): Values within acceptable operating margins
Gate Charge (Qg): Affects switching characteristics
Input Capacitance (Ciss): Influences gate drive requirements
Power Dissipation: Thermal management capability
Product Status: Active status preferred for long-term availability
Compliance: RoHS3 and REACH status for regulatory alignment

Substitute parts listed below meet or exceed the primary criteria. Variations in secondary parameters reflect different manufacturing technologies and design optimizations across manufacturers.

Parameter Comparison

Parameter	FDS6689S (Main)	FDS8870	SI4634DY-T1-E3	AO4430	BSO040N03MSGXUMA1	DMN3010LSS-13	SI4842BDY-T1-E3	TSM042N03CS RLG
Manufacturer	onsemi	onsemi	Vishay Siliconix	Alpha & Omega	Infineon	Diodes Inc.	Vishay Siliconix	Taiwan Semiconductor
FET Type	N-Channel	N-Channel	N-Channel	N-Channel	N-Channel	N-Channel	N-Channel	N-Channel
Vdss (V)	30	30	30	30	30	30	30	30
Id @ 25°C (A)	16 (Ta)	18 (Ta)	24.5 (Tc)	18 (Ta)	16 (Ta)	16 (Ta)	28 (Tc)	30 (Tc)
Rds On @ 10V (mOhm)	5.4 @ 16A	4.2 @ 18A	5.2 @ 15A	5.5 @ 18A	4 @ 20A	9 @ 16A	4.2 @ 20A	4.2 @ 12A
Vgs(th) (V)	3 @ 1mA	2.5 @ 250µA	2.6 @ 250µA	2.5 @ 250µA	2 @ 250µA	2 @ 250µA	3 @ 250µA	2.5 @ 250µA
Qg @ 10V (nC)	78	112	68	124	73	43.7	100	24 @ 4.5V
Ciss @ 15V (pF)	3290	4615	3150	7270	5700	2096	3650	2200 @ 25V
Power Dissipation (W)	2.5 (Ta)	2.5 (Ta)	2.5 (Ta) / 5.7 (Tc)	3 (Ta)	1.56 (Ta)	2.5 (Ta)	3 (Ta) / 6.25 (Tc)	7 (Tc)
Operating Temp (°C)	−55 to 150	−55 to 150	−55 to 150	−55 to 150	−55 to 150	−55 to 150	−55 to 150	to 175
Package	8-SOIC	8-SOIC	8-SOIC	8-SOIC	PG-DSO-8	8-SOP	8-SOIC	8-SOP
Product Status	Obsolete	Active	Active	Not For New Designs	Not For New Designs	Active	Active	Active
RoHS Status	—	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
MSL Rating	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	3 (168 Hours)	1 (Unlimited)	1 (Unlimited)	3 (168 Hours)

Engineering Selection Recommendations

Tier 1: Direct Substitutes (Active Status, Full Compliance)

FDS8870 (onsemi): Maintains onsemi manufacturing lineage with improved specifications. Rated for 18A continuous drain current at 25°C, exceeding the FDS6689S 16A requirement. On-resistance of 4.2mOhm at 18A, 10V provides superior performance. Identical 30V Vdss, 8-SOIC package, and 2.5W power dissipation. RoHS3 compliant. Active product status ensures long-term availability and supply chain stability.

SI4634DY-T1-E3 (Vishay Siliconix): TrenchFET® technology delivers 24.5A continuous drain current at case temperature. Vdss 30V, 8-SOIC package. On-resistance 5.2mOhm at 15A, 10V. Gate charge 68nC provides efficient switching. RoHS3 compliant. Active status. Higher current rating provides design margin for thermal and electrical stress.

DMN3010LSS-13 (Diodes Incorporated): Active product with 16A continuous drain current matching FDS6689S specification. 30V Vdss, 8-SOP package (mechanically compatible with 8-SOIC footprint). On-resistance 9mOhm at 16A, 10V. Lowest gate charge at 43.7nC and lowest input capacitance at 2096pF enable faster switching response. RoHS3 compliant, MSL 1.

SI4842BDY-T1-E3 (Vishay Siliconix): TrenchFET® technology with 28A continuous drain current at case temperature. 30V Vdss, 8-SOIC package. On-resistance 4.2mOhm at 20A, 10V. RoHS3 compliant. Active status. Higher current capability and lower on-resistance support higher power applications.

TSM042N03CS RLG (Taiwan Semiconductor): Highest current rating at 30A continuous drain current at case temperature. 30V Vdss, 8-SOP package. On-resistance 4.2mOhm at 12A, 10V. Lowest gate charge at 24nC at 4.5V and lowest input capacitance at 2200pF enable minimal gate drive power. RoHS3 compliant. Active status. Extended operating temperature to 175°C. MSL 3 requires controlled storage conditions.

Tier 2: Conditional Substitutes (Not For New Designs)

AO4430 (Alpha & Omega Semiconductor): 18A continuous drain current, 30V Vdss, 8-SOIC package. On-resistance 5.5mOhm at 18A, 10V. Power dissipation 3W. RoHS3 compliant. Product status "Not For New Designs" restricts use to legacy system support and maintenance applications only. High input capacitance at 7270pF increases gate drive requirements.

BSO040N03MSGXUMA1 (Infineon OptiMOS™): 16A continuous drain current matching FDS6689S. 30V Vdss, PG-DSO-8 package (mechanically compatible with 8-SOIC). On-resistance 4mOhm at 20A, 10V provides superior performance. Power dissipation 1.56W at ambient temperature. RoHS3 compliant. Product status "Not For New Designs" restricts use to legacy applications. MSL 3 requires controlled storage. Lower power dissipation supports thermal-constrained designs.

Frequently Asked Questions (FAQ)

Q: Can FDS8870 directly replace FDS6689S in existing designs?

A: Yes. FDS8870 maintains identical electrical specifications (30V Vdss, 8-SOIC package, 2.5W power dissipation) while exceeding current rating (18A vs. 16A). On-resistance improvement (4.2mOhm vs. 5.4mOhm) provides performance enhancement. Active product status ensures supply availability. No circuit modifications required.

Q: What is the difference between Ta and Tc current ratings?

A: Ta (ambient temperature) ratings specify continuous drain current at 25°C ambient temperature. Tc (case temperature) ratings specify continuous drain current at 25°C case temperature. Tc ratings typically exceed Ta ratings for the same device. SI4634DY-T1-E3, SI4842BDY-T1-E3, and TSM042N03CS RLG use Tc ratings, indicating higher current capability under controlled thermal conditions.

Q: Are 8-SOP and 8-SOIC packages mechanically interchangeable?

A: 8-SOP and 8-SOIC packages are mechanically compatible with identical 0.154" (3.90mm) width and 8-pin configuration. PCB footprints are identical. DMN3010LSS-13 (8-SOP) and TSM042N03CS RLG (8-SOP) mount directly on FDS6689S (8-SOIC) PCB layouts without modification.

Q: Why do some parts have higher gate charge specifications?

A: Gate charge (Qg) represents the total charge required to switch the transistor from off to on state. Higher gate charge (AO4430 at 124nC) requires greater gate drive current and energy. Lower gate charge (TSM042N03CS RLG at 24nC) reduces gate drive power consumption and enables faster switching. Selection depends on gate driver capability and switching frequency requirements.

Q: What does "Not For New Designs" product status mean?

A: "Not For New Designs" indicates the manufacturer no longer recommends the part for new circuit designs. AO4430 and BSO040N03MSGXUMA1 carry this status. These parts remain available for legacy system maintenance and repair but should not be selected for new product development. Active status parts (FDS8870, SI4634DY-T1-E3, DMN3010LSS-13, SI4842BDY-T1-E3, TSM042N03CS RLG) are preferred for new designs.

Q: How does input capacitance (Ciss) affect circuit performance?

A: Input capacitance represents the gate-to-source and gate-to-drain capacitance. Higher Ciss (AO4430 at 7270pF) increases gate charge and requires higher gate drive current. Lower Ciss (DMN3010LSS-13 at 2096pF, TSM042N03CS RLG at 2200pF) reduces gate drive requirements and enables faster switching transitions. Selection depends on gate driver specifications and switching frequency.

Q: What is the significance of MSL (Moisture Sensitivity Level) rating?

A: MSL 1 (Unlimited) parts like FDS6689S, FDS8870, SI4634DY-T1-E3, AO4430, DMN3010LSS-13, and SI4842BDY-T1-E3 require no special moisture control during storage and handling. MSL 3 (168 Hours) parts like BSO040N03MSGXUMA1 and TSM042N03CS RLG must be stored in controlled humidity environments and have limited shelf life after opening. MSL 3 parts require baking before reflow soldering if storage time exceeds specified limits.

Q: Are all substitute parts RoHS3 compliant?

A: All listed substitute parts are RoHS3 compliant. FDS6689S compliance status was not specified in available data. All active and conditional substitutes meet current RoHS3 environmental regulations, ensuring compatibility with modern manufacturing and regulatory requirements.

Q: Which substitute offers the best thermal performance?

A: TSM042N03CS RLG provides highest power dissipation capability at 7W (case temperature), supporting high-current applications with superior thermal management. SI4842BDY-T1-E3 offers 6.25W (case temperature) and SI4634DY-T1-E3 offers 5.7W (case temperature). BSO040N03MSGXUMA1 provides lowest power dissipation at 1.56W (ambient temperature), suitable for thermally constrained designs.

Q: Can I use a higher-current-rated part as a substitute?

A: Yes. Higher current ratings (FDS8870 at 18A, SI4634DY-T1-E3 at 24.5A, SI4842BDY-T1-E3 at 28A, TSM042N03CS RLG at 30A) provide design margin and thermal headroom. Lower on-resistance values improve efficiency and reduce power dissipation. No circuit modifications are required. Verify gate driver compatibility with gate charge specifications.

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