Linear DC1772A Demo Manual page 4

DEMO MANUAL DC1772A
Quick start proceDure
100%
60VLED 1.0A PWM = INTVCC
98%
96%
94%
92%
90%
88%
86%
84%
82%
80%
0V 5V
Figure 2. DC1772A Efficiency with 60V LEDs at 1A and 100% PWMOUT Duty Cycle
Figure 3. DC1772A 300Hz PWM Dimming Waveforms at Different PWMOUT Duty Cycles
4
10V 15V 20V 25V
PVIN INPUT VOLTAGE (V)
I
LED
1A/DIV
30V 35V 40V
V = 7.7V
DIM
DC
PWM
V = 4V
DIM
DC
PWM
V = 1.5V
DIM
DC
PWM
V = 0.4V
DIM
DC
PWM
0.5ms/DIV
45V 50V 55V
= 96%
= 50%
= 10%
= 4.3%
60V
dc1772af