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The Fast Switching Solution: PANJIT Super Junction MOSFET

2021 December 17 3 min read

What Is a Super Junction MOSFET (SJ-MOSFET)?

Super junction MOSFET (SJ-MOSFET) is a family of MOSFET structures typically used for high voltage MOSFET to achieve low RON (ON-resistance) and high BVdss (drain to source breakdown voltage) with maintaining its fast switching characteristic. The super junction structure refers to the vertical pillars inserted into the epitaxial layers which are used to create a uniform electric field along the y-axis. This uniform electric field consequently allows the design to have higher doping concentration and a thinner epitaxial layer compared to planar MOSFET structures for the same BVdss and RON. Additionally, the super junction structure allows further reduction in RON that is not previously achieved by planar MOSFET. The low RON and fast switching characteristics of SJ-MOSFET make it popular for high-efficiency power converters from 50 W to a few kW power range applications.

Fig. 1 (a) The planar MOSFET structure and its field distribution; (b) the SJ-MOSFET structure and its field distribution (Source: PANJIT) — Fig. 1 (a) The planar MOSFET structure and its field distribution;
(b) the SJ-MOSFET structure and its field distribution (Source: PANJIT)

What Are the Advantages of PANJIT SJ-MOSFETs?

The PANJIT SJ-MOSFETs provide competitive performance with minimal conduction loss and switching loss. Moreover, by having low Vf and high dI/dt ruggedness (>1000A/us turn off current slew rate), the body diodes in the SJ-MOSFETs perform reliably under body-diode hard commutation conditions.

Fig. 2 (a) The V-T and I-T curves of PANJIT SJ-MOSFETs; (b) the V-T and I-T curves of SJ-MOSFETs from Competitor A (Source: PANJIT) — Fig. 2 (a) The V-T and I-T curves of PANJIT SJ-MOSFETs;
(b) the V-T and I-T curves of SJ-MOSFETs from Competitor A (Source: PANJIT)

In the system level test, the peak efficiency of PANJIT SJ-MOSFETs can reach as high as 96% in a 750W boost PFC circuit. In a 750W Gold ATX PSU circuit, the SJ-MOSFETs can reach 92.6% and 90.7% of the peak efficiency for 230V and 115V input voltages, respectively. These test results show that PANJIT SJ-MOSFETs perform well at the system level.

Fig. 3 (a) The efficiency of PANJIT SJ-MOSFETs on 750W PFC test; (b) the efficiency of PANJIT SJ-MOSFETs on 750W Gold ATX PSU test (Source: PANJIT) — Fig. 3 (a) The efficiency of PANJIT SJ-MOSFETs on 750W PFC test;
(b) the efficiency of PANJIT SJ-MOSFETs on 750W Gold ATX PSU test (Source: PANJIT)

What Are the Circuit Applications of PANJIT SJ-MOSFETs?

PANJIT SJ-MOSFETs are suitable for a wide variety of power converter circuits, both hard- and soft- switching topologies. The hard switching topologies, such as single-phase boost PFC, three-phase Vienna PFC, and two-transistor forward (TTF) are suitable applications for SJ-MOSFETs. Along with SJ-MOSFETs, users can choose PANJIT Fast Recovery Diode (FRED) or SiC Schottky Barrier diodes to design the converters for cost-effective purposes or high-efficiency purposes, respectively.

For soft switching converter applications, the following popular topologies are well suitable for PANJIT SJ-MOSFETs: active clamp flyback (up to 100W), LLC converters, PSFB converters, and DAB converters for high power applications (up to a few kW).

The PANJIT SJ-MOSFETs are suitable for the above-mentioned circuit topologies for consumer applications such as quick chargers and power supplies, as well as industrial applications such as server powers, PV inverters, and UPS systems, etc.

Fig. 4 The consumer and industrial applications for SJ-MOSFETs (Source: PANJIT)

Find PANJIT SJ-MOSFETs at TECHDesign

Now you can easily find PANJIT SJ-MOSFETs at TECHDesign. PANJIT SJ-MOSFETs are certified with various industry and consumer standards, and are available in a wide variety of packages, like TO-220, Isolated TO-220, TO-247, and TO-252. Therefore, come to visit TECHDesign immediately to get PANJIT SJ-MOSFETs for your circuit design!