Reference design XDPP1100 fixed-frequency LLC 1 kW quarter brick converter with hybrid soft-start
The 1 kW fixed-frequency LLC converter has a standard DOSA-compliant quarter brick footprint, and achieves 97.3% peak efficiency and power density of 564 W/in³ (34.6 W/cm³), which are enabled by the outstanding performance of Infineon’s semiconductor devices.
The primary OptiMOS™ 6 80 V power MOSFET ISC031N08NM6 has excellent figure of merit and superior switching performance. The low output capacitance reduces the required magnetizing current for ZVS operation in LLC converter, minimizing circulating losses. The secondary OptiMOS™ 5 25 V power MOSFET IQE006NE2LM5 has an industry leading RDS(on), significantly lowering the conduction losses of SRs in LLC converter. The shrink in the form factor (PQFN 3.3 x 3.3 mm footprint) allows more FETs being paralleled in the same space, which further reduces conduction losses and offers superior thermal management. Both the primary and secondary FETs are driven by Infineon’s 2EDL8124G EiceDRIVER™ gate driver, a level-shift high-side low-side dual channel driver offering differential input for super robustness with inherent shoot-through protection.
Infineon’s digital power controller XDPP1100-Q024 plays an essential role in optimal PWM timing generation, duty-cycle/frequency hybrid soft start implementation, and enhanced over current protection. This industry’s smallest digital power controller offers many optimized power processing blocks and pre-programmed peripherals, which enhances the performance of isolated DC-DC converters, reduces external components and minimizes firmware development effort.
- Optimized operation at the resonant frequency
- Hybrid soft-start to limit inrush current
- Ultra fast short circuit protection
- High efficiency intermediate bus converter
- Soft switching with ZVS and ZCS operation
- High power density quarter brick module