Datasheet

NCP3066, NCV3066
http://onsemi.com
11
Figure 16. Buck with External Switch Demoboard Layout Figure 17. Buck with External Switch Demoboard
Photo
350 mA 2 LED
(V
out
= 6.4 V)
Figure 18. Efficiency of Buck LED Driver
INPUT VOLTAGE (V)
EFFICIENCY (%)
700 mA 2 LED
(V
out
= 6.4 V)
350 mA 4 LED
(V
out
= 12.8 V)
700 mA 4 LED
(V
out
= 12.8 V)
Figure 19. Efficiency of Buck LED Driver at I
out
= 3 A
50
55
60
65
70
75
80
85
90
10 15 20 25 30 35
INPUT VOLTAGE (V)
EFFICIENCY (%)
55
60
65
70
75
80
85
90
95
10 15 20 25 30 35
3 A 4 LED
(V
out
= 12.8 V)
3 A 2 LED
(V
out
= 6.4 V)
Figure 15, Buck Demoboard With External Switch
Application Schematic illustrates the NCP3066 being used
as a PFET controller. Table 1. Bill Of Materials shows the
small number of additional parts which are necessary to
assemble mentioned demoboard. The demoboard based on
two layer PCB and the layout is mentioned in Figure 16.
Buck Demoboard Layout. The Line regulation is mentioned
in Figure 20, Line Regulation. The Figure 21, Dimming
characteristic shows behavior of circuitry in case the square
wave signal with 5 V amplitude and 300 Hz frequency was
delivered into ON/OFF pin of device.