Choosing between an IGBT and a MOSFET is one of the most consequential decisions in any power electronics design. Get it wrong and you pay in efficiency losses, thermal failures, or cost overruns. This guide cuts through the physics and gives you a clear, application-by-application framework for making the right call.
Key Takeaways |
| • Use an IGBT above 600 V and at currents above 20–30 A where b ipolar conductivity modulation keeps on-state losses flat regardless of current. |
| • Use a MOSFET below 500 V and at switching frequencies above 50 kHz where fast majority-carrier switching eliminates tail-current losses. |
| • The voltage break-even is 500–650 V for silicon; SiC MOSFETs push this to 1700 V at 3–5× the device cost. |
| • IGBT tail current (0.5–5 µs) is the hard limit on switching frequency — above ~100 kHz, MOSFETs win on total loss regardless of voltage. |
| • Always compute the full loss budget (conduction + switching + gate drive) across the load range before finalising device selection. |
What Are IGBTs and MOSFETs? A Structural Comparison
Both devices are voltage-controlled switches with a high-impedance gate — but their internal carrier physics produce fundamentally different trade-offs.
IGBT (Insulated Gate B ipolar Transistor)
An IGBT is a hybrid device that combines a MOSFET input stage with a b ipolar transistor output stage. When turned on, it floods its drift region with minority carriers (conductivity modulation), dramatically reducing on-state resistance at high voltages. The trade-off is turn-off delay: those carriers must be swept out, producing a characteristic tail current of 0.5–5 µs that limits practical switching frequency to below 100 kHz.
- On-state voltage VCE(sat): ~1.5–3.5 V (near-constant regardless of current)
- Voltage range: 600 V – 6,500 V
- Switching frequency: 1–100 kHz
- High-impedance gate; available in discrete and module formats
MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor)
A MOSFET is a unipolar device — only majority carriers conduct. With no minority carrier storage, it switches in under 10 ns, enabling operation from 100 kHz into the MHz range. The cost is a rapidly rising RDS(on) with voltage rating: silicon MOSFETs become impractical above ~900 V, though Silicon Carbide (SiC) MOSFETs extend the range to 1,700 V+.
- On-state resistance RDS(on): 1–200 mΩ (rises sharply with voltage rating and junction temperature)
- Voltage range: 20–900 V silicon; up to 1,700 V+ for SiC
- Switching frequency: 100 kHz – several MHz
- Includes body diode; body diode Qrr is critical in bridge circuits
Key Advantages: IGBT vs MOSFET Side by Side
1. Conduction Loss
IGBTs use conductivity modulation, giving a near-constant VCE(sat) of ~1.5–2.5 V that makes them highly efficient at high currents (>20 A at 600 V). MOSFET conduction losses follow I²·RDS(on) — for low-voltage (<200 V), low-current applications, this is lower. As voltage and current rise, MOSFETs lose ground because RDS(on) scales roughly as VBR².5 for silicon devices.
2. Switching Speed and Frequency Capability
MOSFETs switch in under 10 ns, enabling frequencies from 500 kHz to several MHz. IGBTs are limited by tail current to below 100 kHz — and practically to 20–30 kHz in high-power motor drive applications where heatsink volume is constrained. Above ~50 kHz, MOSFET total losses are lower than IGBT total losses even at elevated voltages.
3. Voltage Capability
Silicon IGBTs are available up to 6,500 V for HVDC and traction applications. Silicon MOSFETs are practical below ~900 V. SiC MOSFETs bridge the gap at 900–1,700 V with MOSFET-like switching speed, but at 3–5× the device cost of equivalent silicon IGBTs.
4. Short-Circuit and Thermal Robustness
IGBTs offer inherently better short-circuit tolerance: a well-designed 1,200 V IGBT can withstand a hard short for 5–10 µs, giving the gate driver DSP time to detect and respond before device failure. MOSFETs switch faster but support shorter short-circuit withstand times and can sustain higher peak currents that demand faster protection response.
Technical Specifications: What to Check When Selecting a Device
The two parameters that most directly determine application fit are switching frequency and blocking voltage. Use the table below as a cross-reference starting point — always validate against the full datasheet under your specific operating conditions.
| Parameter | Symbol | IGBT Typical Range | MOSFET Typical Range | Unit | Notes |
| Collector/Drain Voltage | VCE / VDS | 600 – 6,500 | 20 – 900 | V | IGBT dominates >600 V; MOSFET preferred <500 V |
| Collector/Drain Current | IC / ID | 10 – 3,600 | 1 – 600 | A | High-current IGBTs used in traction drives |
| On-State Voltage / Resistance | VCE(sat) / RDS(on) | 1.5 – 3.5 V | 1 – 200 mΩ | V / mΩ | IGBT: flat voltage; MOSFET: rises with Tj |
| Switching Frequency | fSW | 1 – 100 | 10 – 10,000 | kHz | IGBTs limited by tail current; MOSFETs excel at MHz |
| Gate Threshold Voltage | VGE(th) / VGS(th) | 4 – 6 | 1 – 4 | V | IGBT typically needs wider drive margin |
| Junction Temperature | Tj | −40 to +175 | −55 to +175 | °C | Similar Tj max in modern devices |
| Thermal Resistance (junc-case) | RthJC | 0.05 – 1.5 | 0.2 – 5 | °C/W | Lower = better for power density |
| Switching Loss | Esw | 0.1 – 5 | 0.01 – 1 | mJ/pulse | IGBT tail current adds turn-off energy |
| Body Diode Reverse Recovery | Qrr | N/A (discrete diode) | 50 – 5,000 | nC | MOSFET body diode Qrr critical in bridge circuits |
| Compliance | — | AEC-Q101, RoHS, REACH | AEC-Q101, RoHS, REACH | — | Both available in automotive and industrial grades |
Break-Even Current: When Does the IGBT Become More Efficient?
For 600 V silicon devices, the cross-over point is approximately 20–30 A at 25°C. Below this threshold, a low-RDS(on) superjunction MOSFET delivers lower total conduction loss. Above it, the IGBT’s flat VCE(sat) dominates. Note that MOSFET RDS(on) roughly doubles at 150°C compared to 25°C, shifting this break-even current lower under real operating conditions.
Total Loss Budget: Conduction + Switching
Always compute total loss = conduction loss + switching loss + gate drive loss across the full load range. At low switching frequency (1–10 kHz), IGBTs typically win on total loss for high-power loads because conduction dominates. Above ~50 kHz, MOSFET switching losses are 5–10× lower per cycle and the balance tips decisively.
Standard (Punch-Through) IGBT vs Trench-Gate Field-Stop IGBT
Within the IGBT family, the choice between legacy punch-through (PT) and modern trench-gate field-stop (FS/NPT) structures has a significant impact on efficiency and thermal performance at the same voltage class.
| Parameter | Standard (Punch-Through) IGBT | Trench-Gate Field-Stop IGBT |
| Structure | Planar gate, n-buffer (PT) | Trench gate, field-stop (FS/NPT) |
| VCE(sat) | Higher (~2.0–3.5 V) | Lower (~1.5–2.2 V at rated current) |
| Switching Speed | Slower; higher tail current | Faster; reduced tail current |
| Short-Circuit Withstand | Moderate (3–5 µs) | Strong (5–10 µs in robust designs) |
| Thermal Performance | Good; larger die area typical | Better W/cm²; more compact modules |
| Typical Applications | Older UPS, legacy motor drives | EV inverters, PFC, modern VFDs |
Design recommendation: For new designs, trench-gate field-stop IGBTs are the default choice due to lower VCE(sat) and faster switching. Standard PT IGBTs remain viable only for legacy replacement or cost-constrained applications where existing gate driver circuitry is already optimised for the older device characteristics.
Packaging and Configuration Options
Discrete Packages
- Through-hole: TO-220, TO-247 — standard for lab prototyping and lower-volume production
- SMD: D²PAK (TO-263), DPAK (TO-252) — for automated SMT assembly in compact designs
Power Modules
High-power designs — traction inverters, UPS, industrial VFDs — use half-bridge or full-bridge IGBT modules (62 mm, EconoPACK, LinPak formats) that integrate multiple dies, freewheeling diodes, and NTC thermistors in a single baseplate package. This simplifies thermal management and reduces parasitic inductance between switches.
SiC MOSFET Formats
SiC MOSFETs are predominantly available in TO-247 discrete packages or dedicated SiC power modules. Gate driver requirements differ from silicon: SiC devices typically need +18 V / −5 V drive voltage versus +15 V / −8 V for IGBTs, and their faster dV/dt (up to 50 V/ns) requires careful attention to gate loop inductance and common-mode EMI.
Temperature Grades
- Commercial (0 to +85°C): Standard consumer and telecom power supplies
- Industrial (−40 to +125°C): VFDs, industrial motor drives, UPS
- Automotive (−40 to +175°C, AEC-Q101): EV traction inverters, on-board chargers, ADAS power rails
Common Application Scenarios
1. Electric Vehicle Traction Inverter — IGBT
A 400 V or 800 V DC-link traction inverter switches phase currents of 200–600 A at 8–16 kHz. The high current and moderate switching frequency precisely favour IGBT modules. A 1,200 V half-bridge IGBT module with integrated NTC thermistor and gate driver isolation delivers peak shaft power while keeping Tj within 150°C. Short-circuit withstand time ≥ 5 µs enables gate driver DSP protection before device failure — a key requirement in ISO 26262-compliant EV designs.
2. High-Frequency LLC Resonant Converter — MOSFET
A server power supply LLC converter running at 300–500 kHz requires primary-side switches with near-zero switching losses. A 600 V silicon MOSFET or 650 V GaN HEMT with gate charge Qg below 10 nC turns on in under 20 ns, enabling zero-voltage switching (ZVS) across the full load range. An IGBT at this frequency would dissipate several watts per device from tail current alone — incompatible with a 95%+ efficiency target. Key parameters: body diode reverse recovery charge (Qrr) and output capacitance (Coss).
3. Synchronous Buck Converter for Data Center Power — MOSFET
A 48 V-to-12 V, 500 kHz synchronous buck converter for data center power distribution uses 60–80 V-rated MOSFETs with sub-5 mΩ RDS(on). The MOSFET body diode enables continuous conduction mode without a separate Schottky diode. Gate charge × RDS(on) figure-of-merit (FOM) is the primary selection criterion, directly impacting controller drive losses and total converter efficiency at 80 Plus Titanium targets (>96% at 50% load).
Manufacturing, Qualification, and Procurement
Both IGBT and MOSFET devices follow ISO 9001 manufacturing standards. Automotive grades additionally require IATF 16949 and AEC-Q101 qualification, including HTRB (High-Temperature Reverse Bias), HTGB (High-Temperature Gate Bias), and IOL (Intermittent Operating Life) stress tests. ESD sensitivity is verified under ANSI/ESDA/JEDEC JS-001 (HBM/CDM), and devices carry MSL 1–3 ratings per IPC/JEDEC J-STD-020.
LCSC supplies authorized IGBTs and MOSFETs with full RoHS and REACH documentation, lot traceability, and Certificates of Conformance. MOQ for standard SMT parts is typically 800–1,500 pcs, with cut-tape options for prototyping. Standard silicon devices are generally in stock; automotive-grade and high-power modules may require 8–16 weeks lead time.
FAQ: Common IGBT vs MOSFET Engineering Questions
Q: At what voltage should I switch from a MOSFET to an IGBT?
The practical crossover is 500–650 V for silicon devices. Below 500 V, modern superjunction MOSFETs (CoolMOS, MDmesh series) offer sufficiently low RDS(on) to outperform silicon IGBTs in both conduction and switching losses. Above 650 V, RDS(on) rises steeply for silicon MOSFETs and 1,200 V-class IGBTs become the cost- and loss-optimised choice. SiC MOSFETs extend the MOSFET-preferred zone to 1,700 V, but at 3–5× the device cost of equivalent silicon IGBTs.
Q: How do I derate an IGBT for reliable continuous operation?
Apply a collector current derating of 70–80% of the datasheet IC rating at maximum ambient temperature. Verify that Tj stays below 125°C (150°C for industrial grade) under worst-case power dissipation, using the thermal resistance chain: RthJC (junction to case) + RthCS (case to heatsink) + RthSA (heatsink to ambient). Collector-emitter voltage should be derated to 80% of VCES to absorb voltage spikes from stray inductance during IGBT turn-off.
Q: Can I replace an IGBT with a SiC MOSFET in my existing motor drive design?
Electrically possible in many cases, but several parameters must be reviewed. SiC MOSFETs have higher VGS(th) sensitivity and require modified gate drive voltages (typically +18 V / −5 V vs +15 V / −8 V for IGBTs). The faster dV/dt (up to 50 V/ns) can excite common-mode currents through motor cable capacitance and stress motor winding insulation. EMI filtering requirements need reassessment. Efficiency gains of 0.5–1.5% at the converter level are typically achievable, which at multi-kW power levels represents measurable energy savings over system lifetime.
Q: What PCB layout rules are critical for high-frequency MOSFET switching?
Minimise power loop inductance by placing high-side and low-side MOSFETs as close as possible and routing drain and source connections on adjacent copper layers with opposite current flow. A stray inductance of 10 nH at a switching speed of 10 A/ns produces a 100 V overshoot on top of VDS. Place gate drive components (Rg, bootstrap capacitor) within 5 mm of the gate pin. Use a dedicated Kelvin source connection for the gate driver return path in high-side configurations to prevent VGS modulation from source inductance during switching transitions.
Q: Which device is better for reducing heat dissipation in a high-power system?
Neither is universally better — the answer depends on current, voltage, and switching frequency. At 400 V, 50 A, 10 kHz, an IGBT typically achieves lower total losses because conduction loss dominates and VCE(sat) is lower than the equivalent MOSFET I²·RDS(on) loss. At 400 V, 10 A, 200 kHz, a MOSFET has 5–10× lower switching energy per cycle and wins on total loss. Always compute the full loss budget — conduction + switching + gate drive — across the full load range before finalising device selection.
Source IGBTs and MOSFETs on LCSC
Whether your design calls for a 1,200 V trench-gate IGBT module for an EV traction inverter or a sub-5 mΩ superjunction MOSFET for a data centre buck converter, LCSC stocks authorized, RoHS-compliant power semiconductors with full lot traceability and datasheet access — including AEC-Q101 automotive-grade options and cut-tape availability for prototyping.
Browse IGBT and MOSFET power devices on LCSC to compare specifications, check real-time stock, and download datasheets and S-parameter files for your next design.
