Newhaven Display Forum

Newhaven Products => Character LCDs => Topic started by: peteralieber@gmail.com on May 20, 2014, 01:24:56 PM

Title: Static discharge killing LCD
Post by: peteralieber@gmail.com on May 20, 2014, 01:24:56 PM
We have had an ESD kill the LCD.  It is still very faint (like the constrast is way down), but definitely not working correctly anymore.  I realize that it is obviously no defective, but what can we do to reduce the LCD module's exposure to ESD?  It will eventually be shipped in a product to users that won't necessarily have ESD protection.
Title: Re: Static discharge killing LCD
Post by: Michael_L on May 20, 2014, 01:35:17 PM
I'm not sure which display you are referring to, but below is a couple of typical things that can be done to reduce ESD exposure:

- Add an ESD protection diode between VDD and Ground
- Ground the bezel of the display
Title: Re: Static discharge killing LCD
Post by: peteralieber@gmail.com on May 20, 2014, 03:18:45 PM
We are using the NHD-0216K3Z-FSRGB-FBW-V3

I thought this module had a protection diode on it.  Also, is the bezel connected to signal ground on the board?
Title: Re: Static discharge killing LCD
Post by: Michael_L on May 20, 2014, 04:59:08 PM
That particular display actually does not have a protection diode on it.  The non-RGB models of this display do however.
I apologize for the confusion, as it does say in the RGB model's spec that it has protection diodes.
We will update this error in the spec right away.

The display's bezel is not connected to signal ground on the board.
Title: Re: Static discharge killing LCD
Post by: lcdusr on April 15, 2015, 12:00:46 PM
We are having the same issue with an NHD-C12832A1Z-FSW-FBW-3V3.

Can you advise the best places for ESD protection?  The symptoms after ESD testing is that the contrast is very low (ie: looks very dim).  Should we add ESD protection to all the voltage pins (ie: V0-V4, C1, C2, Vcc)?

Any other tips?
Title: Re: Static discharge killing LCD
Post by: Michael_L on April 22, 2015, 11:32:25 AM
You can try adding ESD protection on just VDD, or VDD and VCC and run your testing.  Then you will be able to determine if more protection is needed on the V1, V2, etc. lines.