30 levels of backlighting

[MannyH]

Hello all. I am not an active member of the community, but I joined the forum with the hope that maybe somebody here can guide me in the right direction. I am a contractor and working on a job for a customer who has strict requirements on the keyboard that is included on the device. The spec says: "Keyboard shall provide lighted keys that are dimmable to a minimum of 30 incremental positions from the full on to off positions. Low-level white light shall be used for keyboard backlighting". I have endlessly searched the internet trying to find a product that offers this, to no avail. Cherry offers the MX Board 6, which has plenty of levels of lighting, but it is red light. If anybody can provide some suggestions on manufacturers that make something that may fulfill this requirement, that will be greatly appreciated. Thanks!

[Engicoder]

Personally, I only need one level of backlighting: None.

What you are looking for a constant current PWM based LED Driver. The are hundreds if not thousands of different ICs available for this purpose. A popular one is the TI TLC5940.

[kbdfr]

I was under the impression that MannyH is looking for an existing keyboard that can be included in his offer rather than wanting to design one himself.

[Findecanor]

What you are looking for a constant current PWM based LED Driver. The are hundreds if not thousands of different ICs available for this purpose. A popular one is the TI TLC5940.

The situation is not that easy. You can't always drive a full set of LEDs at once, because that could draw more power than what is allowed by the USB spec. The LED driver might need to flicker the LEDs at high speed with LEDs divided into sections, each section being lit while the others are dark. I'm not sure that the TI TLC5940 would do this, but that is how a LED matrix driver operates.

If you talk to an OEM that provides backlit keyboards, I would be surprised if they would not be able to provide white LEDs. You won't need RGB LEDs to get white - a white LED is a special variation of a blue LED with phosphorous that transforms some of the blue light into yellow, which together is white.

[Dudleyaz]

Take a look at the Corsair K70. In addition to having variable white LED backlighting, it does just about every other color you can think of, and you can set different preset patterns. Up market it as a value added feature!
http://www.corsair.com/en-us/landing/k70-rgb

[kbdfr]

I think a Corsair K70



is not exactly what MannyH's "customer who has strict requirements on the keyboard" has in mind.

Source for "lighted keys that are dimmable to a minimum of 30 incremental positions from the full on to off positions":
https://de.scribd.com/doc/309957956/Mil-Std-1472g