Rev. P05

15

VPN12AD02-FU

Digital Dimming:

The PWMI pin can be fed with a pulse width modulated (PWM) signals, this enables when

HIGH and disables when LOW the gate drivers of the main switches.

To avoid unwanted output overshoots due to not soft start assisted startups, PWM dimming in

LOW state should not be used to suspend the output current for long time intervals. To stop in

a safe manner EN/INUVLO=LOW can be used. Following shows the timing diagram of LED

PWM dimming and start up behavior example.

FIG.33 Timing Diagram LED Dimming and Start up behavior example

Analog Dimming:

The analog dimming feature SET pin can adjust the average load current level via the control

enabled is from 200 mV to 1.5 V. The linear average output current can be adjusted by

controlling the voltage at the SET pin between 0.2 V and 1.4 V. The mathematical relation is

given as following equation.