Why Using Newer Si SJ MOSFETs May Not Be a Good Idea for High Frequency Switching

时间： 2021-06-22 来源：fastSiC

技术问答

选型帮助

研发客服

商务客服

Key Takeaways:

· Output capacitance Coss-related loss is the major switching loss in resonant soft switching.

· New generations of silicon super-junction MOSFETs (SJ MOSFETs) dissipate more energy per switching cycle than legacy ones.

· Hysteresis of new generations of silicon super-junction is larger and increases with increasing dV/dt and peak Vds.

Resonant switching techniques are used to reduce the switching loss and increase the power density. Output capacitance (Coss) related loss is the major switching loss in resonant soft switching.

Two papers published in IEEE ISPSD (2018) and TPEL (2019) by G. Zulauf et al. (with Prof. Juan M. Rivas-Davila at Stanford University) showed that new generations of silicon super junction MOSFET are actually dissipating more energy (Ediss) than legacy ones with similar on-resistance. The data presented also show that the Ediss of silicon super junction MOSFET tends to increase with increasing frequency. That means a newer generation of silicon super junction MOSFET may be less suitable to be used in resonant topologies targeting high-frequency operations in spite of a lower stored output capacitance energy (Eoss) noted in the datasheet.

The Ediss is the energy dissipated during each cycle of charging and discharging of Coss. The newer generation of silicon super-junction MOSFET has a smaller pitch and higher doping concentration of n-type drift layer between p-type pillars in order to reduce die size and cost. There is another paper published in IEEE EDL (2019) by Z. Lin of Chongqing Univ. shows that these features may enhance non-linearity and hysteresis of the output charge (Qoss) versus the drain-source voltage Vds curves. The hysteresis area of Qoss-Vds curves also increases with increasing dV/dt in silicon super-junction MOSFETs. Since the hysteresis area is the energy lost during the charge/discharge cycle, this observation explains why Coss related switching loss would be higher for the newer generation of silicon super junction MOSFET, and also suggests that the effect of Ediss increasing with increased switching frequency (higher dV/dt) is going to be more significant for the newer generation of silicon super-junction MOSFETs.

发送到邮箱 |
+1 赞 0
收藏
评论 0
| 转发至：

本文由热心市民小陈转载自fastSiC，原文标题为:Why using newer Si SJ MOSFETs may not be a good idea for high frequency switching View Larger Image，本站所有转载文章系出于传递更多信息之目的，且明确注明来源，不希望被转载的媒体或个人可与我们联系，我们将立即进行删除处理。

全部评论（0）

暂无评论

C-V Curve Matters for Quiet Power Electronics

In this article, we cited some scholars‘ studies on how the intrinsic capacitances of power MOSFETs affect EMI and EMC of power electronics. With more linear capacitance versus voltage (C-V) curve one device has, the better EMI performance the system can behave. Thus, due to the reduced cell pitch which causes more abrupt change in Cgd, designers should pay more attention to the EMI/EMC when using the newer generations of Si SJ MOSFETs.

设计经验发布时间 : 2021-06-23

Achieve Zero Switching Loss with SiC MOSFET

A technical report published in IEEE Transactions on Power Electronics, demonstrated that the switching loss of SiC MOSFET can be completely eliminated under some control strategies.The study was conducted by Prof. Alex Q. Huang’s group at University of Texas at Austin and Prof. Bo Zhang’s group at University of Electronic Science and Technology of China.

设计经验发布时间 : 2021-10-16

【经验】器件承受电流和热量的极限不是来自封装

表面贴装器件可以承受的电流和热量其实更多的是取决于是否有散热槽、铜焊盘大小等因素，而非封装本身的大小。针对散热问题，设计师们在设计功率MOSFET电路时应该更加关注器件的开关损耗和传导损耗等参数。

设计经验发布时间 : 2021-06-12

FH06004 Silicon Carbide Merged PN-Schottky Diode

型号- FH06004,FH06004Z,FH06004Y

数据手册 - 即思创意 - Nov. 2022 PDF 英文下载

即思创意（fastSiC）碳化硅MOSFET和肖特基二极管选型指南

目录- SiC Schottky Diode&SiC MOSFET

型号- FL12190A,FF06100G,FC06008D,FF06100F,FC06006A,FC06008C,FC06008B,FF06100D,FC06008A,FF06320B,FF06320A,FF06030Q,FF17900E,FH06010C,FH06020E-3,FL06320B,FH06020E-2,FL06320A,FC06006D,FC06016C,FC06006C,FF17900Q,FC06010C,FH06004C,FH06006C,FC06002X,FL06150A,FL06320G,FF061K4A,FF12040Q

选型指南 - 即思创意 - 2022/1/18 PDF 英文下载

即思创意碳化硅肖特基二极管及MOSFET选型表

即思创意提供以下参数的技术选型,DC Blocking Voltage(V):650,Total Capacitive Charge(nC):10~45,Capacitance Stored Energy(μJ):1.6~6.5,Continuous Drain Current(A):2.5~60

产品型号	品类	Power Dissipation(W)	Continuous Drain Current(A)	Gate Charge(nC)	Output Capacitive Charge(nC)	Avalanche Energy(mJ)
FL12190A	碳化硅肖特基二极管	88	10	30	41	200

选型表 - 即思创意立即选型

即思创意（FSS）是台湾一家专业的碳化硅功率器件供应商，专注于可降低切换损耗适用于高频操作的超低电容电荷碳化硅肖特基二极管及碳化硅MOSFET。‍全系列采用寄生电感小、小型化、表面贴焊的DPAK及QFN5x6封装。世强是即思创意官方授权一级代理商，代理即思创意碳化硅功率器件，库存丰富，正品保证。

碳化硅肖特基二极管碳化硅MOS管

授权代理商 - 深圳市世强元件网络有限公司线上商城技术资料

展开

【产品】雪崩耐受性强的碳化硅MOSFET FF06030系列，具有更高的系统效率，允许使用高温应用

即思创意推出的碳化硅MOSFET–Falcon Series FF06030具有快速切换行为的优化RDS(on)，能够与标准栅极驱动器兼容，雪崩耐受性强。其具有更高的系统效率，允许使用高温应用并进行高频操作，可靠性高，符合RoHS标准且无卤素。

产品发布时间 : 2022-08-30

30V/395A N-Channel Super Trench II Power MOSFET NCEP008N30GU with the Most Efficient High Frequency Switching Performance

The NCEP008N30GU uses Super Trench II technology that is uniquely optimized to provide the most efficient high frequency switching performance. Both conduction and switching power losses are minimized due to an extremely low combination of RDS(ON) and Qg. This device is ideal for high-frequency switching and synchronous rectification.

产品发布时间 : 2024-03-01

【产品】即思创意650V/2~10A的SiC MPS/JBS肖特基整流器，具备超低的QC特性

即思创意（FSS）推出的最大反向电压为650V的SiC MPS/JBS肖特基整流器，具备超低的QC特性，与主要竞品相比，在传导损耗特性相当的情况下降低了开关损耗（特指二极管结电容充/放电时），这一点特别有助于提升产品的轻载、高频运行效率。

新产品发布时间 : 2021-07-10

A Lower Forward Voltage Drop Does Not Always Bring Benefits

The forward voltage(VF) is an important parameter to Schottky barrier diode, however, junction capacitive charge matters for SBD as well. In some conditions, SBD with a higher VF and a lower Qc can outperform the diode with a lower VF but a higher Qc. That is to say VF*Qc is a better measure (figure-of-merit) should be used to evaluate the performance of SiC Schottky diode.

原厂动态发布时间 : 2021-06-22

30V/40A N-Channel Super Trench Power MOSFET NCEP3040Q, Providing the Most Efficient High Frequency Switching Performance

The NCE NCEP3040Q N-Channel Super Trench Power MOSFET uses Super Trench technology that is uniquely optimized to provide the most efficient high-frequency switching performance. Both conduction and switching power losses are minimized due to an extremely low combination of RDS(ON) and Qg.

产品发布时间 : 2023-11-08