New 650 V Field-Stop IGBT Enables Higher Efficiency and Reliability for Induction Heating

Major efforts are underway by induction-cooktop manufacturers to increase the maximum power and reduce cooking time, while also achieving high system efficiency to meet stringent Energy Star standards.

These trends create new requirements for selecting the appropriate IGBTs which are critical power semiconductors in the induction heating system. Considering the long life spans of cooktops which may be 10-15 years, the right IGBTs should provide low power loss to be efficient and high-reliability capability to be functional for the life of the cooktop.

Based on the system requirements, 650 V Field-Stop (FS) trench IGBTs, such as the FGH40T65SHDF, are ideal for soft-switching applications for induction cooktops and inverter-technology microwave ovens. Additionally, 650 V FS trench IGBT technology has lower conduction loss compared to previous 600 V Field Stop Planar IGBT technology due to 24% lower Vce(sat) characteristics (Figure 1). An additional 50 V higher breakdown voltage provides greater system design margin and reliability advantages.

Figure 1: 600 V FS planar versus 650 V Field-Stop trench IGBT Vce(sat).
(Ic=40 A, Tc=25°C, Rg=6 ohm, Vge=15 V)

(a) New 650 V Field-Stop trench IGBTs        (b) 600 V Field-Stop planar IGBTs

Figure 2: Comparison of Eoff characteristics (input power: 3 KW condition).

Lastly, the new 650 V FS trench IGBT also has lower Eoff, or tail losses, than previous generation 600 V Field-Stop planar IGBT (Figure 2).

Figure 3 shows the summary and comparison of the losses under IH Cooktop set condition; Fsw=25 kHz, (Output Power) Pout: 2.5 KW.

Furthermore, the new 650 V Field-Stop trench IGBTs reduced overall loss by more than 17%.

Figure 3: Comparisons of loss analysis summary between new 650 V Field-Stop trench IGBTs and 600 V Field-Stop planar IGBTs.

Designers who need energy-efficient, highly-reliable IGBTs for soft-switching applications such as induction cooktops and inverter-technology microwave ovens should consider the new 650 V Field-Stop trench IGBT. The new Field-Stop trench IGBT technology is able to optimize the balance between switching and conduction losses.