Newhaven Display Forum

Newhaven Products => Character LCDs => Topic started by: jdavila on October 06, 2016, 10:19:45 AM

Title: NHD-0216K1Z-FL-YBW grounding pad
Post by: jdavila on October 06, 2016, 10:19:45 AM
Hello,
I'm using one of your LCDs on a new design,Part Number NHD-0216K1Z-FL-YBW.

In this particular design, i need to avoid ground loops through the mounting holes, i have seen that this PN has a copper trace that goes from one mounting hole pad to another pad labeled as "JFL"
on the back side of lcd, inside a silkscreen box labeled "K3", this box contains another pad labeled "JF" too.

I think these pads lets you select between connect the display metal frame to the physical ground(mounting hole pad) and the display's reference ground(PIN1 on CON1).

Could you please confirm that i had to cut this copper trace to effectively isolate display from ground?

Do you have any information regarding the "JFL" & "JF" pads and what functionality do they offer?

Best Regards
Jesus
Title: Re: NHD-0216K1Z-FL-YBW grounding pad
Post by: jdavila on October 06, 2016, 10:27:55 AM
Please ignore, I have already received the information i need by mail from Saurabh Baxi | Applications Engineer
Thanks a lot for your kind support.
Title: Re: NHD-0216K1Z-FL-YBW grounding pad
Post by: abb on December 09, 2016, 04:41:17 PM
I'm curious what the resolution here was. We use a different part (NHD-0420DZW-AB5), but it has similar connections and components. It appears JHG connects the display metal frame to the mounting hole chassis ground through a 0 Ohm resistor, and then JFG connects the chassis ground to the digital ground through a 100 kOhm resistor.

The same basic questions apply. Can JFG be eliminated or perhaps increased to a 1 MOhm resistor?

EDIT: Or, alternatively, can JHG be removed? Which would be most recommended?
Title: Re: NHD-0216K1Z-FL-YBW grounding pad
Post by: Saurabh_B on December 12, 2016, 08:13:09 AM
Hello, Here's the reply I gave:

As the display is without having those jumpers populated pin 1 on the connectors is not linked to the mounting holes.
You wouldn’t need to cut the trace so long as the JFL remains unpopulated.

The first pad is connected to the mounting hole located on the bottom left of the picture below.
The second pad (K3) is connected to the plate for the Bezel Tabs.
The final pad (JF) is connected to the ground of the display. (Pin 1 on both CON and CON1)