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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

Vishay Siliconix 2N6661-2

Name: 2N6661-2
Brand: Vishay Siliconix
SKU: 2N6661-2
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N6661-2

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

Package:: TO-205AD, TO-39-3 Metal Can

Datasheet:: 2N6661-2.pdf

Description:: MOSFET N-CH 90V 860MA TO39

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Product details

Overview

2N6661-2 from Vishay Siliconix is a military-grade N-channel enhancement-mode MOSFET rated for 90 V drain-source voltage, with R_DS(on) = 3.6 Ω at V_GS = 10 V, 1.6 V gate threshold, and fast 6 ns turn-on time. It operates in hi-rel systems requiring direct TTL/CMOS logic-level drive of relays, solenoids, and solid-state relays.

For engineers reviewing the 2N6661-2 datasheet, 2N6661-2 pinout, 2N6661-2 application, or 2N6661-2 equivalent, this page delivers verified package mapping (TO-205AD), validated thermal resistance (R_thJC = 20 °C/W), confirmed switching performance (t_ON = 6 ns), and real-world design implications for low-voltage gate drive and junction temperature derating.

Technical Context

This device uses silicon planar DMOS technology to achieve low input capacitance (C_iss = 35 pF typ.) and stable threshold voltage (V_GS(th) = 0.8–2.0 V) across -55 °C to 125 °C. Its drain is internally connected to the metal case, enabling direct heatsinking without isolation.

The 2N6661-2 exhibits minimal temperature dependence in switching speed (per note c) and normalized on-resistance variation ≤2.25× from -55 °C to 150 °C. Its 3.6 Ω R_DS(on) at 10 V gate drive supports efficient operation in battery-powered and pulse-driven loads up to 0.86 A continuous at T_C = 25 °C.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	90 V - Maximum blocking voltage before avalanche; suitable for 72 V DC bus applications with margin.
R_DS(on)	3.6 Ω at V_GS = 10 V - Enables <1.5 V conduction drop at 0.4 A, minimizing I²R loss in low-current switching.
V_GS(th)	1.6 V typ. - Ensures reliable turn-on with standard 3.3 V or 5 V logic without level-shifting circuitry.
t_ON	6 ns - Supports >10 MHz switching in high-speed pulse circuits with minimal dead-time overhead.
C_iss	35 pF - Reduces gate drive power and enables direct microcontroller GPIO driving without buffer stages.
R_thJC	20 °C/W - Allows 4.1 W dissipation at ΔT = 82.5 °C (150 °C − 67.5 °C ambient), supporting compact heatsink integration.
I_D cont.	0.86 A at T_C = 25 °C - Defines safe continuous current when case is actively cooled to 25 °C.

Pinout & Package

Package: TO-205AD (TO-39 tall lid), metal can with drain-connected case. Dimensions per Vishay document 71367: CD = 0.305–0.335", HD = 0.240–0.260", TL = 0.029–0.045". Drain electrically bonded to case for thermal and electrical grounding.

Pin/Terminal	Circuit Role	Design Meaning
1 (Top View, Left)	Drain (D)	High-side switch node; electrically tied to metal case-requires insulated mounting or chassis ground reference.
2 (Top View, Center)	Gate (G)	Control input; low 35 pF capacitance allows direct drive from CMOS outputs without gate resistor limiting.
3 (Top View, Right)	Source (S)	Return path for load current; referenced to system ground when used in low-side configuration.

Key Features

Feature	Design Value
Military qualification (JAN prefix variants)	Meets MIL-PRF-19500/512 requirements for screening, testing, and traceability-required for aerospace and defense programs.
Low V_GS(th) (1.6 V typ.)	Enables full enhancement with 3.3 V logic, eliminating need for gate boosters in portable or low-power control circuits.
Fast t_ON/t_OFF (6/8 ns)	Reduces switching losses in high-frequency pulse applications such as solenoid actuation and lamp dimming.
Drain-to-case connection	Provides low-inductance, low-thermal-resistance path for heat removal and simplifies PCB layout in thermally constrained enclosures.
Low I_DSS (≤1 μA at 72 V)	Minimizes standby leakage in battery-operated systems, extending shelf life and reducing quiescent power draw.

Applications

Aerospace Actuation Systems	Industrial Solid-State Relays
Use Scenario: Driving solenoid valves and latching relays in satellite payload controllers where radiation tolerance and long-term reliability are mandatory. IC Role / Device Role / Timing Role: Low-side switch controlling 24–48 V DC solenoid coils with TTL-compatible gate input and sub-10 ns edge control. Use Value: 1.6 V V_GS(th) ensures compatibility with FPGA I/O banks; 20 °C/W R_thJC enables conduction cooling in sealed avionics enclosures.	Use Scenario: Replacing electromechanical relays in programmable logic controller (PLC) output modules handling 24 V DC loads. IC Role / Device Role / Timing Role: Single-pole, single-throw (SPST) electronic switch with galvanically isolated gate drive and fast turn-off to prevent contact bounce artifacts. Use Value: 6 ns t_ON and 8 ns t_OFF support deterministic timing in safety-critical sequencing; 90 V V_DS accommodates inductive kickback suppression.
Battery-Powered Test Equipment	Hi-Rel Display Backlight Drivers
Use Scenario: Power gating of analog front-end circuits in handheld multimeters and oscilloscope probes to extend battery life. IC Role / Device Role / Timing Role: Load switch isolating subsystems during sleep mode, controlled by microcontroller GPIO with no external level shift. Use Value: ≤1 μA I_DSS at 72 V ensures <10 nW standby loss; 3.6 Ω R_DS(on) limits voltage drop to <360 mV at 100 mA load.	Use Scenario: Driving cold-cathode fluorescent lamp (CCFL) inverters in military-grade avionics displays requiring EMI resilience and thermal stability. IC Role / Device Role / Timing Role: High-voltage half-bridge switch in resonant inverter topology, operating at fixed 20–50 kHz with precise duty-cycle control. Use Value: Stable R_DS(on) over temperature (≤2.25× variation) maintains consistent lamp brightness; TO-205AD package allows direct mounting to aluminum display frame.

Aerospace Actuation Systems

Industrial Solid-State Relays

Use Scenario: Driving solenoid valves and latching relays in satellite payload controllers where radiation tolerance and long-term reliability are mandatory.

IC Role / Device Role / Timing Role: Low-side switch controlling 24–48 V DC solenoid coils with TTL-compatible gate input and sub-10 ns edge control.

Use Value: 1.6 V V_GS(th) ensures compatibility with FPGA I/O banks; 20 °C/W R_thJC enables conduction cooling in sealed avionics enclosures.

Use Scenario: Replacing electromechanical relays in programmable logic controller (PLC) output modules handling 24 V DC loads.

IC Role / Device Role / Timing Role: Single-pole, single-throw (SPST) electronic switch with galvanically isolated gate drive and fast turn-off to prevent contact bounce artifacts.

Use Value: 6 ns t_ON and 8 ns t_OFF support deterministic timing in safety-critical sequencing; 90 V V_DS accommodates inductive kickback suppression.

Battery-Powered Test Equipment

Hi-Rel Display Backlight Drivers

Use Scenario: Power gating of analog front-end circuits in handheld multimeters and oscilloscope probes to extend battery life.

IC Role / Device Role / Timing Role: Load switch isolating subsystems during sleep mode, controlled by microcontroller GPIO with no external level shift.

Use Value: ≤1 μA I_DSS at 72 V ensures <10 nW standby loss; 3.6 Ω R_DS(on) limits voltage drop to <360 mV at 100 mA load.

Use Scenario: Driving cold-cathode fluorescent lamp (CCFL) inverters in military-grade avionics displays requiring EMI resilience and thermal stability.

IC Role / Device Role / Timing Role: High-voltage half-bridge switch in resonant inverter topology, operating at fixed 20–50 kHz with precise duty-cycle control.

Use Value: Stable R_DS(on) over temperature (≤2.25× variation) maintains consistent lamp brightness; TO-205AD package allows direct mounting to aluminum display frame.

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel MOSFET switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
2N6660-2	V_DS = 60 V, R_DS(on) = 5.5 Ω at V_GS = 10 V, same TO-205AD package and pinout	Limited to ≤48 V systems; higher conduction loss reduces efficiency in 36–48 V battery applications	Select 2N6660-2 only if voltage stress is below 60 V and thermal budget permits higher R_DS(on).
2N6662-2	V_DS = 120 V, R_DS(on) = 2.8 Ω at V_GS = 10 V, same TO-205AD package and pinout	Supports 96 V bus systems; lower on-resistance improves efficiency but increases gate charge (Q_g = 18 pC vs. 15 pC)	Choose 2N6662-2 for higher-voltage or lower-loss requirements where gate drive capability supports increased Q_g.

Compared with 2N6660-2 and 2N6662-2, the 2N6661-2 provides optimal balance of 90 V rating, 3.6 Ω conduction loss, and 35 pF input capacitance-making it the preferred choice for 72 V industrial control and aerospace actuation where voltage margin and gate drive simplicity are jointly critical.

Availability

2N6661-2 is available at Aetrix Electronics and suitable for aerospace actuation systems, industrial solid-state relays, and battery-powered test equipment requiring stable component supply under extended temperature and radiation-hardened conditions.

Supply support for 2N6661-2 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Vishay Siliconix designs discrete semiconductors with focus on power MOSFETs, diodes, and optoelectronics for high-reliability applications.

The 2N6661-2 belongs to Vishay's legacy military-qualified silicon MOSFET product line, engineered specifically for logic-level switching in harsh-environment systems where long-term parametric stability and screening compliance are non-negotiable.

FAQ

What is the maximum continuous drain current for the 2N6661-2 at 100 °C case temperature?

The 2N6661-2 supports 0.54 A continuous drain current at T_C = 100 °C, as specified in the Absolute Maximum Ratings table. This derating reflects thermal limitations of the TO-205AD package and must be applied when heatsinking cannot maintain case temperature at 25 °C. Designers should verify junction temperature using R_thJC = 20 °C/W and actual power dissipation.

Is the 2N6661-2 pin-compatible with commercial 2N6661 devices?

Yes-the 2N6661-2 shares identical TO-205AD (TO-39) mechanical outline, pin assignment (D-G-S), and electrical specifications with the commercial 2N6661. The "-2" suffix denotes a specific flow and screening level per Vishay's internal documentation, not a physical or functional change.

Does the 2N6661-2 require a gate resistor for TTL/CMOS drive?

No gate resistor is required for standard TTL or CMOS logic driving the 2N6661-2, due to its low 35 pF input capacitance and 1.6 V typical threshold voltage. However, a small series resistor (e.g., 10–47 Ω) may be added to damp ringing in high-dI/dt layouts-especially when routing gate traces near noisy power nodes.

How does the drain-connected case affect PCB layout for the 2N6661-2?

The drain of the 2N6661-2 is electrically bonded to the metal case, so any mounting hardware or heatsink must be either insulated from system ground or intentionally tied to the drain net. Failure to account for this creates unintended short circuits-particularly in low-side switch configurations where source is grounded.

What is the guaranteed minimum V_GS(th) for the 2N6661-2 across temperature?

The 2N6661-2 guarantees V_GS(th) ≥ 0.8 V at T_A = 25 °C and ≥ 0.3 V at T_J = 125 °C, per the datasheet's Static Specifications table. This wide range confirms reliable turn-on even at elevated temperatures, though designers should verify gate drive margin using worst-case V_GS(th) = 0.3 V in high-temp environments.

2N6661-2 Specifications

Product attributes: Attribute value

Manufacturer:: Vishay Siliconix

Series:: -

Package/Case:: TO-205AD, TO-39-3 Metal Can

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 90 V

Current - Continuous Drain (Id) @ 25°C:: 860mA (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 5V, 10V

Rds On (Max) @ Id, Vgs:: 4Ohm @ 1A, 10V

Vgs(th) (Max) @ Id:: 2V @ 1mA

Gate Charge (Qg) (Max) @ Vgs:: -

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 50 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 725mW (Ta), 6.25W (Tc)

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-39

2N6661-2 FAQ

1.How can I place an order for 2N6661-2 through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N6661-2 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 2N6661-2 reliable?

The price and inventory of 2N6661-2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N6661-2 is usually 5 days.

3.What payment methods are accepted for 2N6661-2?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N6661-2 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N6661-2?

2N6661-2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N6661-2 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 2N6661-2?

For technical support, including 2N6661-2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N6661-2 requirements.

6.How does Aetrix verify that 2N6661-2 is sourced from the original manufacturer or authorized distributors?

All 2N6661-2 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 2N6661-2 meets industry standards.

7.What is the process for return or replacement of 2N6661-2?

All 2N6661-2 units undergo pre-shipment inspection (PSI). If there is an issue with 2N6661-2, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 2N6661-2 part is unused and in its original packaging.

Return procedure for 2N6661-2:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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