AN2783 datasheet(28/47 Pages) STMICROELECTRONICS

28 / 47 page

Layout guidelines

AN2783

28/47

More in detail:

Place the TVS close to the input diode bridges, if possible on the same side

Place the PM8800 and all the related components close to each other, use both sides

Place all the feedback components close to each other, use both sides

Place the sense resistors close to the power MOSFET, if possible on the same side

Place the input ceramic capacitors close to the input side of power transformer, if

possible on the same side

Place the primary snubber network close to the power transformer, on the bottom side

Place the rectifier diode close to the output side of the transformer, if possible on the

same side

Place the secondary snubber network close to the rectifier diode, bottom side

Place the output ceramic capacitors close to the rectifier diode and the power

transformer, on the copper areas, top side

Place the last ceramic capacitors close to the output terminal of the power connector,

bottom side

10. Place the 100 nF input capacitor close to the VSS and GND pins

11. Place the decoupling capacitors for VCC close to the relevant PM8800 pin

12. Place the components for RT and SS pins in a quiet area, separated as much as

possible from other signals

13. Use paths of at least 20 mils for signals connected to the IC pins 5,10,11

14. Connect the PM8800 pins 8,9,16 directly to the copper areas

15. Use a wide path or copper area for VIN, AUXI and AUXII networks

AN2783 데이터시트(PDF) 28 Page - STMicroelectronics