This application note describes the characteristics and features of a 65 W demonstration board (EVL6566B-65W-QR), tailored to the specifications of a typical hi-end portable computer power supply. The peculiarities of this design are the very high average efficiency of about 90%, without synchronous rectification, and very low no-load consumption of 100 mW at 230 Vac. The result is that this converter is more than compliant with Energy Star® eligibility criteria (EPA rev. 2.0 EPS).
This application note describes the characteristics and features of a 65 W demonstration board (EVL6566B-65W-QR), tailored to the specifications of a typical hi-end portable computer power supply. The design utilizes a 19 V output at 3.42 A continuous operation with a universal input mains range of 90 to 264 Vac.
| Output voltage | 19 V @ 3.42 A continuous operation |
|---|---|
| Input mains range | 90 + 264 Vac - frequency 45 + 65Hz |
| Standby consumption | <100 mW @ 230 Vac |
| Average efficiency | better than 89% |
| Dimensions | 58x121 mm |
The maximum switching frequency is set at about 165 kHz.
The design uses a standard 800 V, STF7NM80 MOSFET in a TO-220FP package.
The transformer uses a standard ferrite size EER28L.