Newhaven Display Forum

Newhaven Products => Graphic LCDs => Topic started by: davepfz on September 30, 2015, 12:47:59 PM

Title: Driving the backlight LED for NHD-C12864WC-FSW-FBW-3V3
Post by: davepfz on September 30, 2015, 12:47:59 PM
The LED voltage for the NHD-C12864WC-FSW-FBW-3V3 is specified as 3.0V at a current of 36mA. Does this mean that there is an internal current limiting resistor? None is shown in the drawing.

Although I don't expect to go there, what is the maximum current for the LEDs? (I plan to use a dimming circuit that will allow the user to adjust the backlight.)

Thanks
Title: Re: Driving the backlight LED for NHD-C12864WC-FSW-FBW-3V3
Post by: Michael_L on October 01, 2015, 08:37:36 AM
This display does not have a current limiting resistor, one should be used when powering the backlight.
The maximum current for the backlight on this display is 50mA.
Title: Re: Driving the backlight LED for NHD-C12864WC-FSW-FBW-3V3
Post by: raspdroid on January 24, 2016, 07:16:44 AM
Hello,

I am using this model for my project  with 3V3 voltage with one TPS61201, http://www.newhavendisplay.com/specs/NHD-C12832A1Z-FSR-FBW-3V3.pdf

It suffices with one resistor or is it better to use a 3.0V LDO?

TPS7703DBVR
http://www.ti.com/lit/ds/symlink/tps770.pdf

Regards
Title: Re: Driving the backlight LED for NHD-C12864WC-FSW-FBW-3V3
Post by: Paul_B on January 25, 2016, 08:33:11 AM
Morning,

It is typically preferred to supply the displays Typ. Voltage when ever possible, however in your case supplying 3.3V is perfectly acceptable  ;)
Title: Re: Driving the backlight LED for NHD-C12864WC-FSW-FBW-3V3
Post by: raspdroid on January 25, 2016, 12:27:38 PM
Thanks Paul,

Then I'll used 3V3 for supply and backlight.

Best regards
--Javier