Datasheet DK1203 (Dongke Semiconductor) - 5

SHENZHEN DONGKE SEMICONDUCTOR CO., LTD SMALL POWER OFF-LINE SWITCH MODE POWER CONTROLLER -DK1203 8.2.7 The primary inductance
V ×T 110× 7.7 s on L = = ≈1.2mH p I 720 p
8.2.8 Leakage inductance of a transformer
It is suggested to use P/S/P way to wind the transformer so that to reduce the leakage inductance. Important notice:
9. SPECIAL NOTICE FOR PBC LAYOUT DESIGN 9.1
Heat dissipation: A good estimate is that the controller will dissipate the output power. So enough cooper area connected to the 7, 8 COLLECTED pins and tin-plating are necessary to provide the controller heat sink.
9.2
The 7, 8 COLLECTED pins is high voltage part of the IC, peak voltage is as high as 600V, so it should be at least 1.5mm far away from the low voltage part in the PCB as to avoid circuit breakdown and discharging. Address: Building 18, Hejing industrial zone, Heping village, Fuyong, Baoan Area, Shenzhen, China. 5 Tel: 86-755- 29598396 Email: [email protected] Website: www.dkpower.cn