What is the best power semiconductor for high voltage batteries?

Automobile manufacturers are accelerating their move toward electrification in order to become carbon neutral. Until now, the mainstream battery voltage for electrified vehicles was around 300V for HEVs, but as P-HEVs and BEVs become mainstream in the future, the battery voltage will increase to 400V to 500V or even 800V all at once. There is also a movement to become. In the case of a battery voltage of 800V, the power semiconductor to be used must have a withstand voltage of 1200V because the withstand voltage of 650V, which has been generally used for automobiles, does not meet customer requirements. In addition, electric vehicles are required to improve the efficiency of the power supply system to improve the electric power consumption, which is equivalent to fuel consumption.

Therefore, attention is focused on SiC FETs, which can significantly reduce switching loss and conduction loss compared to conventional silicon power semiconductors. Qorvo 's newly released 4th generation 1200V​ ​FET series is the best solution for automotive on-board chargers (OBC) and DC/DC converters to meet the needs and challenges of car manufacturers. And like its predecessor, the new SiC FETs are also ideal for industrial battery chargers and power supplies, PV converters, UPS, and a variety of other power conversion applications.

Why is the 4th generation 1200V FET superior?

World's highest on-resistance achieved with advanced vertical trench device structure x area(Ron x A), these new devices are the smallest RDS (on) x area, smallest RDS (on) x Eoss, RDS(on) x Coss,(tr), RDS(on) x Qg Provides the industry's highest figure of merit, including

other Gen4 Similar to the portfolio, the new 1200V FETs teeth, 0 ~ 12V or 0 ~ 15V can be easily driven by the gate drive of +/-20V VGS, Max and high threshold voltage (4.8V) with these SiC FETs provides sufficient gate voltage design and noise margin, Si or SiC Compatible with gate drive voltage. 1200V FETs has an excellent forward voltage (usually 1.0 ~ 1.5V) and low reverse recovery charge (Qrr), providing superior integrated diodes.

To take full advantage of the ultra-low on-resistance, a new 1200V SiC FETs employs an advanced silver sintering die attach process that provides excellent thermal performance. These devices have best-in-class thermal resistance Rth, jc The reduced die results in lower capacitance and reduced switching losses while maintaining the excellent power handling capability enabled by the . Figure the benefits of improved thermal resistance 2 is shown. against competing technologies Gen 4 1200V SiC FETs relative die size and other in the same class FETs thermal resistance compared to 26 %~ 60 % decrease.

figure 3 is power handling (R. _th,jc), hard switching (R. _DS(on) x Eoss), soft switching R. _DS(on) x Coss,(tr),and R. _DS(on) xQg new figure of merit for Gen4 1200V SiC FETs is shown as a reference. A good performance for each parameter in the radar chart is represented by a low value.

1200V Gen4 SiC FETs teeth, twenty five ℃ and high temperature (125 °C) in both hard-switching (i.e. active front-end etc.) and soft-switching (i.e. isolated DC/DC converter) circuits offer uncompromising performance benefits. previous generation SiC FETs Compared to , the new device has the maximum 40 %low R. _DS(on), 37 %low R. _DS(on) x Eoss @25 °C, and 54 %low R. _DS(on) x Coss @25 Provides ℃.

Application design example using 4th generation 1200V FET

Design Example 1: Active Front End for On-Board Charger (OBC) Applications

Six new 1200V SiC FETs are available in Qorvo 's free online design calculator FET-Jet Calculator ™. It can be used to evaluate device losses, converter efficiency, temperature rise, and identify optimal driving conditions. Using the FET-Jet Calculator tool, it is clear that the new 23 mΩ (UF4SC120023K4S) and 30 mΩ (UF4SC120030K4S) FETs are the best options for active front-ends in 800V bus on-board charger (OBC) applications. .

In the 11kW OBC front-end design example shown in Figure 4, the new UF4SC120030K4S achieves reduced losses (to 37W per FET), excellent 98 % efficiency, lower temperature rise (Tj = 115 °C), All due to the shrinking die size. The design below assumes a hard switching frequency of 150kHz and a heatsink temperature of T _HS = 80 °C, allowing users to achieve excellent power density.

Design example 2: Isolated DC/DC converter (CLLC)

new 1200V SiC FETs The series is OBC isolation of DC/DC Also great for converters (CLLC). For these high-frequency soft-switching topologies, the 4th generation FETs low conduction loss, low diode forward drop, low driver loss (low Vg, low Qg), and low R. _DS(on) x Coss,(tr) is ideal.

figure Five to the 11kW, 800V full bridge of CLLC A design example is shown. for each primary switch position 1200V SiC FETs there is. The expected operating frequency is 200 kHz and heatsink temperature T. _HS =80 ℃. FET-Jet Calculator ™ predicted performance summary table with the new Gen4 1200V SiC FETs shows the benefits of With a similar die size, UF4C120053K4S/K3S has lower losses and better efficiency (99.5 %) and operates at lower temperatures (Tj<100 °C). cost effective UF4C120070K4S/K3S has an attractive cost / It's also a performance solution, with slightly higher losses and better efficiency (99.4 %).

Summary

These new 1200V SiC FETs from Qorvo offer excellent performance in hard and soft switching enabled by advanced 4th generation technology in high voltage circuits.

Key "figures of merit" provide overall superior performance SiC FET products that provide optimal power solutions in cutting-edge designs for high-growth markets.
For more information on these new devices, please visit https://www.qorvo.com.

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