AN2300

Figures

Rev1

3/21

Figures

Figure 1.

Capacitive converter schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2.

Buck converter modified schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3.

Buck basic operation during the switch TON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 4.

Buck basic operation during the switch TOFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 5.

Modified Buck current flow at Iout2 = 0. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 6.

Modified Buck current flow at Iout2¼0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 7.

Buck converter with VIPer12A, schematic A (Vout1 referred to GND) . . . . . . . . . . . . . . . . . 8

Figure 8.

Buck with VIPer12A, schematic B (Vout1 referred to -5V) . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 9.

PCB layout based on schematic B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 10.

Buck waveforms (schematic A) @230VAC, full load; Ch1=VS, Ch2=Vout2, Ch3=Vout1,

Ch4=IL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 11.

Buck waveforms (schematic B) @230VAC, full load; Ch1=VS, Ch2=Vout2, Ch3-Ch2=Vout1,

Ch4=IL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 12.

Capacitive converter line regulation, at full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 13.

Buck converter line regulation (schematic A), at full load . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 14.

Buck converter line regulation (schematic B), at full load . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 15.

Efficiency vs Vin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 16.

Capacitive converter: conducted emission @ 230VAC, full load: Phase . . . . . . . . . . . . . . 12

Figure 17.

Capacitive converter: conducted emission @ 230VAC, full load: Neutral . . . . . . . . . . . . . 12

Figure 18.

Buck converter: conducted emission @ 230VAC, full load: Phase . . . . . . . . . . . . . . . . . . 13

Figure 19.

Buck converter: conducted emission @ 230VAC, full load: Neutral . . . . . . . . . . . . . . . . . . 13

Figure 20.

Line regulation @full load (Buck converter, schematic A) . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 21.

Line regulation @full load (Buck converter, schematic B) . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 22.

Out1 load regulation @ Iout2 = 0 (Buck converter, schematic A). . . . . . . . . . . . . . . . . . . . 14

Figure 23.

Out2 load regulation @ Iout1 = 20mA (Buck converter, schematic A) . . . . . . . . . . . . . . . . 14

Figure 24.

Out1 load regulation @ Iout2 = 0 (Buck converter, schematic B). . . . . . . . . . . . . . . . . . . . 15

Figure 25.

Out2 load regulation @ Iout1 = 20mA (Buck converter, schematic B) . . . . . . . . . . . . . . . . 15

Figure 26.

Efficiency vs Vin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 27.

Efficiency comparison between schematics A and B for IDz2 = 30mA . . . . . . . . . . . . . . . 16

Figure 28.

Schematic A modifications for 4V < Vout1 < 11V (Vout2 @ 5V) . . . . . . . . . . . . . . . . . . . . 17

Figure 29.

Schematic B modifications for 9V < Vout1 < 16V (Vout2 @ 5V) . . . . . . . . . . . . . . . . . . . . 17