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Vishay Siliconix IRF840LC
- Part No.:
- IRF840LC
- Manufacturer:
- Vishay Siliconix
- Category:
- FETs, MOSFETs
- Package:
- TO-220-3
- Datasheet:
-
IRF840LC.pdf
- Description:
- MOSFET N-CH 500V 8A TO220AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,647
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Product details
Overview
IRF840LC from Vishay Siliconix is a 500 V, 8.0 A N-channel power MOSFET in TO-220AB package, featuring 0.85 Ω RDS(on) at VGS = 10 V, 39 nC total gate charge, and repetitive avalanche rating-designed for high-frequency switch-mode power supplies, DC-DC converters, and motor control circuits.
For engineers reviewing the IRF840LC datasheet, IRF840LC pinout, IRF840LC application, or IRF840LC equivalent, key selection criteria include its 500 V blocking voltage, ultra-low gate charge enabling efficient high-speed switching, ±30 V gate rating for robust drive margin, and proven ruggedness in unclamped inductive switching.
Technical Context
This device employs Vishay's LCDMOS technology to achieve significantly reduced Qg, Qgs, and Qgd versus conventional MOSFETs-enabling MHz-range operation at high current. Its 1.0 °C/W junction-to-case thermal resistance supports 125 W continuous dissipation at TC = 25 °C with proper heatsinking.
The IRF840LC integrates a fast-recovery body diode (trr = 490–740 ns, Qrr = 3.0–4.5 μC) and is rated for repetitive avalanche energy (EAR = 13 mJ) and single-pulse avalanche (EAS = 510 mJ), making it suitable for snubberless inductive load switching.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDS | 500 V - Supports primary-side switching in offline SMPS up to 400 V DC bus with safety margin. |
| RDS(on) | 0.85 Ω @ VGS = 10 V - Enables low conduction loss at 8 A continuous drain current (TC = 25 °C). |
| Qg | 39 nC - Reduces gate driver power requirement and enables >1 MHz switching with moderate drive strength. |
| tr/tf | 25 ns / 19 ns - Supports fast edge rates critical for minimizing switching transition losses in hard-switched topologies. |
| EAS | 510 mJ - Allows reliable operation in unclamped inductive turn-off without external snubbers (e.g., relay drivers). |
| TJ Range | −55 °C to +150 °C - Qualified for industrial and automotive under-hood ambient conditions with derating. |
Pinout & Package
IRF840LC is housed in a through-hole TO-220AB package with standard lead form, electrically isolated tab (drain-connected), and 3-pin configuration optimized for vertical mounting with heatsink interface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| G (Gate) | Control terminal | Accepts 10 V logic-level drive; ±30 V absolute max rating prevents gate oxide damage during transients. |
| D (Drain) | High-side power output | Connected to internal die substrate and metal tab; requires electrical isolation when mounted to heatsink. |
| S (Source) | Power return reference | Common node for gate drive return and current sensing; low-inductance layout critical for dV/dt immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low gate charge (Qg = 39 nC) | Reduces gate driver IC power consumption and allows use of lower-cost microcontroller GPIOs with external buffer. |
| Enhanced 30 V VGS rating | Provides 10 V headroom above standard 20 V gate drive rails, improving noise immunity and reliability in noisy environments. |
| Repetitive avalanche rated (IAR = 8.0 A) | Enables robust operation in flyback, forward, and resonant converters where inductive energy must be safely clamped. |
| Low Ciss/Coss/Crss (1100/170/18 pF) | Minimizes Miller effect and improves controllability during high dV/dt transitions, reducing risk of spurious turn-on. |
Applications
| Switch-Mode Power Supply | DC-DC Converter |
|---|---|
|
Use Scenario: Primary-side switch in 50–200 W offline AC-DC adapters and open-frame PSUs. IC Role / Device Role / Timing Role: High-voltage power switch controlling energy transfer via transformer primary winding. Use Value: 500 V VDS and 510 mJ EAS eliminate need for external RCD snubber in discontinuous conduction mode (DCM) operation. |
Use Scenario: Synchronous rectifier or high-side switch in isolated 12 V–48 V industrial DC-DC modules. IC Role / Device Role / Timing Role: Fast-turning power transistor managing PWM-controlled energy storage in coupled inductors or transformers. Use Value: 25 ns rise time and 39 nC Qg support 500 kHz–1 MHz operation while maintaining <1% switching loss contribution. |
| Motor Drive | Inductive Load Switching |
|
Use Scenario: Half-bridge leg in 24–48 V BLDC fan or pump controllers. IC Role / Device Role / Timing Role: Low-side or high-side switching element commutating phase current with dead-time control. Use Value: Body diode trr ≤ 740 ns and Qrr ≤ 4.5 μC minimize cross-conduction losses and voltage spikes during freewheeling. |
Use Scenario: Solenoid, relay, or valve driver in programmable logic controller (PLC) output modules. IC Role / Device Role / Timing Role: Unclamped inductive turn-off switch absorbing stored magnetic energy via avalanche breakdown. Use Value: 13 mJ repetitive avalanche energy rating ensures >100,000 cycles at 8 A inductive current without degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar N-channel power MOSFET applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STP5NK50ZFP | 500 V, 4.5 A, RDS(on) = 1.4 Ω, Qg = 23 nC, TO-220FP package (full-pack, no isolated tab) | Lower current rating and higher RDS(on); not rated for repetitive avalanche | Prefer for space-constrained PCB layouts where heatsink isolation is unnecessary and peak current ≤4.5 A. |
| IXTP50N10P | 100 V, 50 A, RDS(on) = 0.022 Ω, Qg = 105 nC, TO-220AB package | Lower voltage rating but much higher current and lower on-resistance; higher gate charge increases drive demand | Prefer for low-voltage, high-current DC loads (e.g., battery-powered motor drives) where 500 V capability is unnecessary. |
Compared with STP5NK50ZFP and IXTP50N10P, the IRF840LC uniquely balances 500 V capability, 8 A current, and 39 nC gate charge-making it optimal for mid-power industrial SMPS where both voltage margin and switching efficiency matter.
Availability
IRF840LC is available at Aetrix Electronics and suitable for switch-mode power supplies, DC-DC converters, motor drives, and inductive load switching requiring stable component supply across extended production lifecycles.
Supply support for IRF840LC 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 is a global leader in discrete semiconductors, specializing in high-reliability MOSFETs, diodes, and optoelectronics for industrial, automotive, and computing applications.
The IRF840LC belongs to Vishay's LCDMOS low-charge power MOSFET family, engineered specifically to reduce gate drive losses and enable high-frequency switching in compact, cost-sensitive power conversion systems.
FAQ
What is the maximum continuous drain current for the IRF840LC at 100 °C case temperature?
The IRF840LC supports 5.1 A continuous drain current at TC = 100 °C, per its linear derating curve from 8.0 A at 25 °C. This value reflects thermal limits of the TO-220AB package and must be validated with actual heatsink performance and ambient conditions in the final design. The IRF840LC datasheet specifies this rating under steady-state conduction with proper thermal interface.
Does the IRF840LC have a fully isolated drain tab?
Yes-the IRF840LC uses a TO-220AB package with electrically isolated drain tab, meaning the metal mounting surface is connected only to the drain terminal and not internally shorted to other pins. This allows direct mechanical attachment to a grounded heatsink without additional insulation, provided creepage/clearance requirements are met. The IRF840LC's isolation rating supports typical industrial mounting practices.
Is the IRF840LC suitable for use in zero-voltage switching (ZVS) resonant converters?
Yes-the IRF840LC's low Coss (170 pF) and Crss (18 pF), combined with fast switching times (tr = 25 ns, tf = 19 ns), support ZVS operation in LLC and series-resonant topologies up to several hundred kHz. Its body diode recovery characteristics (trr = 490–740 ns) also help maintain soft-switching behavior. The IRF840LC performs reliably when gate timing aligns with resonant tank zero-crossings.
What is the gate threshold voltage range for the IRF840LC?
The IRF840LC has a gate-source threshold voltage (VGS(th)) range of 2.0 V to 4.0 V at TJ = 25 °C and ID = 250 μA. This ensures consistent turn-on behavior across manufacturing lots while allowing compatibility with standard 5 V and 10 V gate drivers. The IRF840LC remains fully enhanced well within typical logic-level drive margins.
How does the IRF840LC's avalanche rating compare to standard MOSFETs without this specification?
Unlike standard MOSFETs, the IRF840LC is explicitly tested and rated for repetitive avalanche (IAR = 8.0 A, EAR = 13 mJ) and single-pulse avalanche (EAS = 510 mJ). This means it can repeatedly absorb inductive energy without parametric shift or failure-critical in snubberless designs. The IRF840LC's ruggedness is verified per JEDEC JESD24-11 and documented in Vishay's reliability reports.
IRF840LC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay Siliconix
- Series:
- -
- Package/Case:
- TO-220-3
- Packaging:
- Tube
- Product Status:
- Active
- FET Type:
- N-Channel
- Technology:
- MOSFET (Metal Oxide)
- Drain to Source Voltage (Vdss):
- 500 V
- Current - Continuous Drain (Id) @ 25°C:
- 8A (Tc)
- Drive Voltage (Max Rds On, Min Rds On):
- 10V
- Rds On (Max) @ Id, Vgs:
- 850mOhm @ 4.8A, 10V
- Vgs(th) (Max) @ Id:
- 4V @ 250µA
- Gate Charge (Qg) (Max) @ Vgs:
- 39 nC @ 10 V
- Vgs (Max):
- ±30V
- Input Capacitance (Ciss) (Max) @ Vds:
- 1100 pF @ 25 V
- FET Feature:
- -
- Power Dissipation (Max):
- 125W (Tc)
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220AB
IRF840LC FAQ
1.How can I place an order for IRF840LC through Aetrix?
Please submit a Request for Quotation (RFQ) for IRF840LC 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 IRF840LC reliable?
The price and inventory of IRF840LC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRF840LC is usually 5 days.
3.What payment methods are accepted for IRF840LC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRF840LC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IRF840LC?
IRF840LC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IRF840LC 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 IRF840LC?
For technical support, including IRF840LC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRF840LC requirements.
6.How does Aetrix verify that IRF840LC is sourced from the original manufacturer or authorized distributors?
All IRF840LC 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 IRF840LC meets industry standards.
7.What is the process for return or replacement of IRF840LC?
All IRF840LC units undergo pre-shipment inspection (PSI). If there is an issue with IRF840LC, 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 IRF840LC part is unused and in its original packaging.
Return procedure for IRF840LC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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