Linear Technology DC1775A Demo Manual page 4

DEMO MANUAL DC1775A
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Output Voltage and Switch Node Voltage During Output Open
IC_V
IN
20V/DIV
V
OUT
20V/DIV
V
SW
200V/DIV
Output Current and Switch Node Voltage During Output Short
IC_V
IN
20V/DIV
I
OUT
2A/DIV
V
SW
200V/DIV
LED Current vs TRIAC Dimming Angle
Figure 12. LED Current vs TRIAC Dimming Angle: Solid Line, 120VAC 60Hz; Dot Line, 220VAC 50Hz.
Note: For Different Types of TRIAC Dimmers, the Maximum and/or Minimum Dimming Angle May
Vary, Which Gives Different Maximum and/or Minimum LED Current
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200ms/DIV
Figure 8. V = 90VAC
IN
100ms/DIV
Figure 10. V = 90VAC
IN
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
0
IC_V
IN
20V/DIV
V
OUT
20V/DIV
V
SW
200V/DIV
IC_V
IN
20V/DIV
I
OUT
2A/DIV
V
SW
200V/DIV
220VAC 50Hz
APPLICATION
120VAC 60Hz
APPLICATION
30 60 90 120 150 180
TRIAC DIMMING ANGLE (DEGREES)
200ms/DIV
Figure 9. V = 270VAC
IN
100ms/DIV
Figure 11. V = 270VAC
IN
dc1775afa