Targeting the third-generation semiconductor sector, NATIONSTAR further enhances its product portfolio!

Recently, the NATIONSTAR Research Institute has launched the NSiC-KS series packaged in TO-247-4L, which can be applied in portable energy storage, photovoltaic inverters, new energy vehicle charging piles and other scenarios, adding another powerful solution to the new energy market

The "Star" Package in SiC MOSFET

NATIONSTAR NSiCKS

With the rapid advancement of Industry 4.0 and the popularization of new energy vehicles, industrial power supplies and high-voltage chargers are imposing increasingly stringent requirements on power device performance, such as switching loss and power density.As an advanced high-frequency device, SiC MOSFET boasts outstanding advantages including high voltage endurance, low on-resistance, and low turn-on loss, and is rapidly gaining share in the new energy market.

Leveraging its leading packaging technologies and scientifically optimized design, NATIONSTAR has adopted the TO-247-4L package with an auxiliary source pin for its NSiC-KS series SiC MOSFETs, achieving new breakthroughs in switching loss, drive design and other key performance indicators for discrete devices.

What are the highlights of NATIONSTAR NSiC-KS?

A direct comparison tells the full story.▼

Taking NATIONSTAR’s third-generation semiconductor NSiC series 1200V 80mΩ SiC MOSFET as an example, we compare the conventional TO-247-3L package with the NSiC-KS (TO-247-4L) package in four aspects:package design, turn-on loss, switching loss, and switching frequency & false turn-on risk.

☜ Quick takeaway – conclusion first:SiC MOSFETs using the NSiC-KS package eliminate the shared source path between the drive loop and power loop, achieving full decoupling of the two loops.This results in significantly lower turn-on loss and switching loss, higher switching frequency, reduced parasitic inductance, and lower false turn-on risk.

1. Package Design

Compared with the TO-247-3L package, the NSiC-KS series adds an extra S pin, also known as the auxiliary source or Kelvin Source (KS) pin.

2 . Turn-on Loss

■ TO-247-3L Package

During the turn-on phase of the SiC MOSFET, the drain current ID​ rises rapidly.The high current slew rate induces a large positive voltage drop Lsource​⋅dtdID​​ (positive at the top, negative at the bottom) across the stray inductance Lsource​ of the power source.

This voltage drop causes the actual gate voltage VGS_real​ across the SiC MOSFET die at the moment of turn-on to be lower than the applied drive voltage — it is reduced by the voltage generated across Lsource​.

As a result, the gate voltage drops sharply at turn-on, slowing the rise of ID​ and increasing turn-on loss Eon​.

NSiC-KS Package

Thanks to the Kelvin Source (KS) pin, no large current flows through the gate loop, eliminating interference from the main power loop.The gate of the chip can accurately sense the driving voltage, thereby reducing turn-on loss.

Actual measurement comparison shows that the NSiC-KS package reduces turn-on loss by approximately 55% compared with the conventional TO-247-3L package.

3. Switching Loss

The Kelvin Source (KS) pin in the NSiC-KS package separates the power source pin from the driver source pin, reducing the effect of parasitic inductance and fully unleashing the high-speed switching performance of the SiC MOSFET.

According to measured comparison data, the NSiC-KS package reduces switching loss by approximately 35% compared to the TO-247-3L package.

4. Switching Frequency & False Turn-on Risk

■ At Turn-on:

For the TO-247-3L package, when high current passes between drain and source, the inductance effect of the source pin reduces the gate turn-on voltage and slows down the conduction speed.

In the NSiC-KS package, the added Kelvin Source (KS) pin weakens the source pin inductance effect, so the VGS​ voltage across the SiC MOSFET is nearly equal to the gate drive voltage VDRV​.

Therefore, as shown in the figure below, compared with the TO-247-3L package, the NSiC-KS package helps improve the switching speed of the SiC MOSFET.

At Turn-off:

In the NSiC-KS package, no large current flows through the gate loop, so almost no reverse induced electromotive force VLS​ is generated.This results in extremely low crosstalk from the power loop, reduces the oscillation amplitude of VGS​ during turn-off, and lowers the risk of false turn-on.

NATIONSTAR NSiC-KS SiC MOSFET Products

Multiple Options Available to Meet Diverse Needs

To meet market demands, NATIONSTAR provides a range of models for its NSiC-KS SiC MOSFET products.Leveraging its complete production line for SiC discrete devices, NATIONSTAR can deliver high-performance, highly reliable and premium product and technology solutions tailored to customer requirements.

Accumulating Strength for Long-Term Growth.

NATIONSTAR continues to implement an innovation-driven development strategy, deepening its presence in the third-generation semiconductor packaging and testing sector. The company is actively breaking through key technological barriers, providing more high-quality "Star" solutions for the domestic development of third-generation semiconductors in China, and injecting strong "Star" power into the industry.