Preliminary Datasheet

LP3302

LP3302B6F-00

Version 1.0 Datasheet

May.-2013

www.lowpowersemi.com

Page 12 of 13

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%.