LP3302 Datasheet, PDF (12/13 Pages) Lowpower Semiconductor inc – 1.1MHz Fixed-Frequency PWM Operation

Preliminary Datasheet
LP3302
c. Using a Filtered PWM signal
Another common application is using a filtered PWM
signal as an adjustable DC voltage for LED dimming
control. A filtered PWM signal acts as the DC voltage
to regulate the output current. The recommended
application circuit is shown in the Figure 6. In this
circuit, the output ripple depends on the frequency of
PWM signal. For smaller output voltage ripple
(<100mV), the recommended frequency of 2.8V PWM
signal should be above 2kHz. To fix the frequency of
PWM signal and change the duty cycle of PWM signal
can get different output current. According to the
application circuit of Figure 5, output current is from
20.5mA to 5.5mA by adjusting the PWM duty cycle
from 10% to 90%.
LP3302B6F-00 Version 1.0 Datasheet May.-2013 www.lowpowersemi.com
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