Delivering the energy to each sever and telecom systems uses power and generates heat, which requires additional energy in cooling system. Every watt consumed by server and telecom equipments generally waste at least another watt through cooling, power backup, and power delivery. Therefore, a major effort in modern data and telecommunication power systems has been increasing the efficiency and the power density in order to meet the system requirements. Power Quad Flat No-lead (PQFN) package, which is widely used in low voltage applications, is a surface mount package to achieve power density and small form factor requirements of many applications. PQFN88 (8mm x 8mm) or Power88 package is a new leadless package for high voltage super-junction MOSFET. This package provides excellent switching performance thanks to lower parasitic source inductance and Kelvin source configuration.

AEP3221 Need to Minimize your system size and Maximize your system efficiency Figure 1

Figure 1. Comparisons of Package Dimension and Footprint area between standard SMD package, D2PAK and New Leadless Package, Power88

 As shown in Figure. 1, this new package has very low profile with 1mm ultra slim thickness. Compared to the industrial standard D2PAK package for high voltage MOSFET, the Power88 is 60% smaller foot print with an area of 64mm2. Comparing loop inductances in Figure 2, standard D2PAK’s gate drive circuitry includes common source inductance, while the Power88 package separates power and driver source to minimize common source inductance influence during switching transient. As shown in Table I, Power88 package provides very lower parasitic inductance to achieve excellent switching performance compared to D2PAK. The approximate common source inductance value of Power88 package is 3nH versus the D2PAK’s 7nH common source inductance. Compared to a D2PAK, Power88 package can reduce both source and gate inductances to lower the power dissipation and unwanted noise when switching.

AEP3221 Need to Minimize your system size and Maximize your system efficiency Figure 2          (a) Standard gate drive schematic (D2PAK)                     (b) Kelvin source gate drive schematic (Power88)

Figure 2. Comparison of Gate drive schematic with parasitic source inductance between standard SMD package, D2PAK and new leadless package, Power88 (Kelvin Source Configuration) 

TABLE I

Comparisons of Approximate Parasitic Inductances for Each Package

AEP3221 Need to Minimize your system size and Maximize your system efficiency Table 1

Figure 3 shows the summary of the switching losses with variable gate resistor under VDD=400V, ID=8A. As shown in the switching loss analysis, turn-on loss of SuperFET® II MOSFET in PQFN88 is greatly reduce because the silicon’s di/dt slew rate is higher while the lower common source inductance of the PQFN88 package with separated power and driver GND minimize voltage and current ringing.

AEP3221 Need to Minimize your system size and Maximize your system efficiency Figure 3

Figure 3. Comparisons of switching performance summary between SuperFET® II MOSFET in Power88 between SuperFET® II MOSFET in D2PAK under VDD=400 V, ID=8 A 

As power conversion efficiency becomes more and more critical and technology of discrete devices advances every day. Extremely fast switching of super-junction MOSFET is essential choice for higher efficiency. The new leadless HV Power88 package maximize switching performance and enable achieving high efficiency and low profile in power supply systems.

Related Links: 

View SuperFET II/SuperFET II Easy-Drive MOSFET Product Portfolio:
http://www.fairchildsemi.com/search/controller?searchText=superfet+ii&textBtn.x=0&textBtn.y=0

Try our new Power88 package, FCMT199N60 − N-Channel SuperFET® II MOSFET
http://www.fairchildsemi.com/pf/FC/FCMT199N60.html?keyword=FCMT199N