Difference between Analog Dimming and Digital Dimming in LED

[FreshmanNewbie]

I would like to understand the difference between the Analog dimming and the digital dimming in the LED Drivers.

I went through this article where there is some difference indication on page 4. But still not able to get total clarity on this.

As far as I understand, both ADIM and DIM control the output forward current of the LED. DIM can do it in PWM. Where ADIM needs voltage within a specific range. What are the differences that one can obtain using ADIM and DIM is what I am finding difficult to understand.

 

[KlausST]

Hi,

I don´t know what answer you expect. .. since "analog", "digital", "DC" and "PWM" are quite common phrases.

Also the given datasheet explains it rather clear:

Analog dimming adjusts the DC forward current through the LED, ...
...
PWM dimming modulates the average current with a different duty cycle,

So, can you explain what is unclear?

Klaus

 

[danadakk]

Analog dimming quite straightforward, basically controlling the current thru LED(s) with
either a variable current source or in the case of series LED strings a variable V source.

PWM dimming uses the concept of average current and property of eye persistence.
LED is turned on to full brightness, then turned off, each with time period controlled
by PWM. So over a cycle the average current thru LED is varied by the % of time LED is
on versus off. And if cycle fast enough, eye persistence sees the light not as a series
of pule on/off but as a steady average of the current over time in the repeated on/off
cycle.

https://assets.lutron.com/a/documents/048360.pdf

https://www.ijsr.net/archive/v3i11/T0NUMTQxMTYx.pdf

PWM LEDs: Pulse Width Modulation for Dimming Systems and Other Applications

PWM is ideally suited for applications needing to maintain specific characteristics of the LED, for example, efficiency, color, or temperature.

resources.pcb.cadence.com

Regards, Dana.