• We recently switched our forum platform. If you experience any issues please email support@crystalfontz.com

Low Power Backlight Options for 80mmx36mm backlight LCD display (1x16 or Graphic)

raddybaby

New member
Hi All,

I am upgrading an existing product - its a handheld tester that uses a 9V battery. We need to keep the same enclosure with its 9V battery compartment...hence same display size & low power consumption requirement.

We currently use a EL backlit 1x16 display due to the low power comsumption (2mA for the dispaly plus 5 mA for the back-light). This display is almost obsolete and I am struggling to find a direct replacement - the LED backlights for the equivalent displays are very power hungry (100mA) so they are not an option.

I am considering switching to a graphic display as I am happy to write the code to drive it...it would also give the product a more "bling" The graphic LED backlights use a lot less current (32mA) but I am also hopeful that somebody (cyrstalfontz!?!?) will consider stocking an EL version. I know the EL option "exist" as the options appear on various manufacturer's websites.

My questions:

1. Has anybody used PWM to dim a graphic LED backlight? If so what realistic power savings can be achieved?...reducing the current draw to 15mA for the backlight would be accceptable - assuming it made the unit fairly easy to read...I do not need a flashlight!

2. Is there a source or minimal order quantityfor a EL backlight version of a 80mmx32mm (module dimension) LCD display?

3. Why has EL back-lighting become so "unpopular"?

Any and all advice would be greatly appreciated!

Cheers,
Neal
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.
 
1. Has anybody used PWM to dim a graphic LED backlight? If so what realistic power savings can be achieved?...reducing the current draw to 15mA for the backlight would be accceptable - assuming it made the unit fairly easy to read...I do not need a flashlight!
PWM dimming is pretty common. You should be able to get usable results with 30% to 50% duty cycle, but you would have to be the judge of that.
3. Why has EL back-lighting become so "unpopular"?
My opinion:
Needs HV inverter circuit.
Poor CRI for color displays
Not very bright compared to LED
Dimming not as effective/linear
 

CF Tech

Administrator
The CFAX12864U1-TFH-TS has to be one of the coolest and lowest power small graphics + touch screen out there:

http://www.crystalfontz.com/product/CFAX12864U1-TFH-TS


There is also the non-touch screen version:

http://www.crystalfontz.com/product/CFAX12864U1-TFH


The best thing you can do with the backlight to save power is turn it off or down. If the user is not interacting, turn it off. The darker it is, the less backlight you need, turn it down if it is really dark :)

If that one is too big, there is the CFAX12864T1-TFH:

http://www.crystalfontz.com/product/CFAX12864T1-TFH
 
Top