This guide is the entry point to the Good-Ark silicon carbide library. It maps the SiC decisions—which voltage class, which device (MOSFET or diode), which topology, and how hot the design can run—and points to the dedicated articles that carry the detail. Use it to position the design before the datasheet comparison.
The SiC Decision Map
The SiC choice follows four questions:
- What voltage class? The DC-link voltage and the transient margin set the class: 650 V for universal-input PFC and server power, 1200 V for 800 V EV and solar stages, 1700 V for 1500 V DC systems. The 650 V, 1200 V, and 1700 V articles each carry the derating detail for their class.
- MOSFET or diode? The switch roles belong to SiC MOSFETs; the rectifier and freewheeling roles belong to SiC Schottky diodes. The 1200 V SiC diode article covers the diode side, and the SiC Schottky article covers the PFC recovery story.
- What topology? The topology decides the device stress: CCM boost versus totem-pole PFC for the 650 V class, 2-level versus 3-level for the 1500 V class. The topology sections of the 650 V and 1700 V articles carry the comparison tables.
- How hot, and for how long? The junction-temperature and lifetime decision belongs to the high-temperature SiC reliability article, which covers power cycling, mission profiles, and the materials around the die.
Voltage × Topology × Device Table
| DC link | Device class | Typical topology | Key article |
|---|---|---|---|
| 400 V | 650 V SiC MOSFET + SiC diode | CCM boost, totem-pole PFC | 650 V SiC article, SiC Schottky article |
| 800 V | 1200 V SiC MOSFET + 1200 V diode | Boost, LLC, DC-DC | 1200 V SiC MOSFET article, 1200 V SiC diode article |
| 1000 V solar | 1200 V with margin | String inverter | 1200 V SiC MOSFET article |
| 1500 V solar / rail | 1700 V, or 3-level with 1200 V | 2-level or NPC/T-type | 1700 V SiC article |
The table is a screening map, not a rule: the final class depends on the clamped worst-case voltage, the surge profile, and the standard’s requirements.
The Crossovers That Decide
Three crossovers recur in SiC designs, and each has its own article:
- SiC vs super junction at 650 V. Frequency, efficiency target, and the totem-pole body-diode requirement decide it; the crossover method is in the 650 V article.
- SiC MOSFET vs IGBT at 1200 V. Switching frequency, cooling, and system cost decide it; the IGBT side is in the 1200 V IGBT article, and the SiC side in the 1200 V SiC article.
- Temperature vs lifetime. The junction-temperature target trades cooling against lifetime; the method is in the high-temperature reliability article.
Reliability and Derating at a Glance
The reliability view of SiC is a set of disciplines covered across the library:
- Voltage derating. Size the class from the clamped worst-case, not the nominal bus (1200 V and 1700 V articles);
- Thermal derating. Read the allowable junction temperature from the lifetime curves, not the absolute maximum (high-temperature reliability article);
- Gate drive. The SiC voltage window, negative off-state, and CMTI are the driver selection inputs (gate-drive guide);
- Materials. The package, TIM, solder, and PCB must be rated for the operating temperature (high-temperature reliability article).
Derating Arithmetic
The voltage-class decision is margin arithmetic, and the worked examples live in the voltage-specific articles: the 1200 V article carries the 800 V-bus margin method, the 1700 V article carries the 1500 V-bus and topology decision, and the high-temperature reliability article carries the junction-temperature and mission-profile side. This guide assigns the class by DC-link voltage and points to those pages; it does not repeat the calculations.
The SiC gate-drive window is summarized in the checklist below; the full sizing, timing, and isolation decisions are in the gate-drive guide and the isolated-driver article.
Where to Go Next
- 650 V class: 650V SiC MOSFETs for PFC and Server Power (this series);
- 1200 V class: 1200V SiC MOSFETs for Solar Inverters and EV Chargers (this series);
- 1500 V class: 1700V SiC MOSFETs for 1500V Solar and Rail Power (this series);
- Diodes: SiC Schottky Barrier Diodes in PFC and 1200V SiC Diodes (this series);
- Reliability: High-Temperature SiC Reliability (this series);
- For the families and datasheets, the PV inverter application section and Documents are the starting points; for project support, contact Good-Ark.
A SiC Design Checklist
- Fix the DC-link voltage and the worst-case transient before choosing the class.
- Pick the topology (2-level, 3-level, or bridge) and the device roles (switch or diode).
- Size the loss from the hot curves at the operating temperature and frequency.
- Run the derating arithmetic for voltage, altitude, and temperature.
- Verify the gate-drive window and the driver’s CMTI against the switching speed.
- Set the junction-temperature target from the lifetime curves, not the absolute maximum.
- Verify the thermal path and the materials at the operating temperature.
- Compare at the system level—magnetics, cooling, efficiency, and cost—before committing.
Application Pointers
The same map lands differently in each application, and the dedicated articles carry the detail:
- Server and telecom PFC. The 650 V class and the totem-pole topology concentrate the SiC story; the 650 V article’s crossover and topology tables apply directly.
- EV chargers. The 1200 V class serves both the PFC and the isolated DC-DC stages; the 1200 V MOSFET and diode articles carry the device ratings, and the isolated DC-DC module article covers the auxiliary supply.
- Solar inverters. The bus voltage decides the class: 1000 V arrays use 1200 V with margin, 1500 V arrays force the 1700 V or 3-level decision; the 1700 V article’s topology and derating sections apply.
- Industrial drives. The IGBT side of the comparison is in the IGBT articles, and the SiC crossover is the frequency and efficiency calculation in the 1200 V article.
Each pointer is a starting route, not a complete design; the map plus the linked article carries the method.
What to Ask the Supplier
The design map ends at the datasheet, and the datasheet ends at the supplier’s evidence. For a SiC design-in, request:
- The datasheet revision and the change history for the candidate part;
- The RDS(on)-versus-temperature and switching-energy curves at the operating conditions;
- The body-diode and Coss/Qoss data for the topology;
- The power-cycling and thermal-cycling qualification data with the test conditions and scope;
- The gate-drive window and the driver recommendation;
- The supply and qualification documents covering the exact part, site, and date range.
The list mirrors the checklist earlier in this guide, applied to the vendor. A supplier that can produce the evidence in the application’s context—not just the catalog page—is the partner the design can rely on through qualification and production.
Which SiC Page Should I Read?
- I am choosing a voltage class for a DC link. Start with the 650 V, 1200 V, or 1700 V article, depending on the bus and the transient margin.
- I am selecting a diode for a rectifier or freewheeling role. Read the SiC Schottky article for PFC physics, and the 1200 V SiC diode article for the 1200 V device ratings.
- I am deciding the operating temperature and lifetime. Read the high-temperature SiC reliability article.
- I am designing the gate drive. Read the gate-drive guide and the isolated-driver article.
- I am comparing SiC with silicon or IGBTs. Read the 650 V and 1200 V crossover sections in the corresponding articles.
The decision tree routes the reader to the page that owns the task, keeping this guide to the system-level map.
Frequently Asked Questions
How do I choose between SiC and silicon for a new design? Run the system-level comparison at the operating point—frequency, efficiency target, thermal budget, and cost. The crossover methods in the 650 V and 1200 V articles show the calculation; the technology label alone does not decide. The comparison should include the magnetics and cooling the frequency enables, because that is where the SiC premium usually pays back.
Do I need a special gate driver for SiC? Yes, the drive window differs from silicon, and the fast edges demand good CMTI. The gate-drive guide in this series covers the sizing, timing, and isolation decisions, and the 650 V article conditions when the negative off-state is truly required.
Is SiC always more expensive than silicon? At the device level, usually yes; at the system level—magnetics, cooling, efficiency, and enclosure—the premium often pays back. The comparison is the system, not the bill of materials, and the crossover shifts with frequency and temperature as the dedicated articles show.
The Map, Then the Datasheet
SiC design starts with the map—voltage class, device type, topology, and temperature—and finishes with the datasheet. Work the four questions in order, use the dedicated articles for the detail, and the SiC decision becomes a set of engineering trade-offs instead of a technology argument. The map also tells you when SiC is not the answer, which is as valuable as knowing when it is; the honest answer to a crossover question is often silicon, and the map is built to give it. Either way, the decision is documented, defensible, and repeatable for the next design.