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displaytech 164G FC BW-3LP

Hello,

I have a question about the backlight of the Displaytech PN : 164G FC BW-3LP 

I'm using this part on my current design with some modifications on current supply for the Backlight. In your datasheet you mention IF= 48mA TYP @VF=3.5V.

I need to know the limits of the use of the Backlight LED when the VF=5V and a serie resistor of 6 ohm is inserted with the backlight (by calculation i must have 250mA accross the Backlight), i measure 101mA.

what is the risk on LED life time ? How much time will be reduced ?

Thank you

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Replies

engineering_seacomp's picture
engineering_seacomp
May 7, 2020

Hi,

Overdriving LEDs does shorten the life, but I do not know by how much because there would have to be a study on this, and I do not have that data.

I wish I could be more help than this.

anis's picture
anis
May 10, 2020

Hi,

This will not help me so much.

Can I have the reference of the LED mounted on the 164G FC BW-3LP ?

How many LED are mounted on this reference ? arrangement ?

herbroy's picture
herbroy
October 19, 2020

Hi,

I ordered a 164G FC BW3LP to replace a 164A FC BW3LP with a dim LED.

WE can only see the proper display when at an extreme angle from the bottom.  

It is not acting at al like the 164A with respect to viewing angle.  Is there something wrong with the display or is this how it should work.  

we would asusme you could read it proply straight on but it does not work that way.

terry_seacomp's picture
terry_seacomp
October 20, 2020

Hi @herbroy,

Do you have a photo you can show? That sounds strange. It could be a contrast issue and minor adjustments in voltage could have a significant impact on contrast and in turn viewing angle. Can you try this?

herbroy's picture
herbroy
October 21, 2020

Pictures attached.

We are not the manufacturer of the device using your LCD just a user replacing an old LCD that lost it's ability to display background LED light.

As you can see it is well lighted but difficult to read.

We have the devices contrast set to 0% which is best for viewing.  not sure what voltage they are sending for this, could you tell us how to check?

We know the LED voltage is at pins 15 and 16.

Hopefully you can understand what we mean by the angles we show.

terry_seacomp's picture
terry_seacomp
October 21, 2020

@herbroy- thanks for the pics. It looks like the LCD is getting too much voltage which is turning "on" pixels that are meant to be off. You can see the whole dot matrix of each character until you get to the last image. Reducing the voltage to the LCD may correct this.

@engineering_seacomp Can you assist further?

herbroy's picture
herbroy
October 22, 2020

Terry_seacomp

Thanks, we looked at the board and found that connected to Pin 3 is R6.  The value of that resistor is 0.  When we changed it to 10K ohms it works great.  The voltage went from -.56v to -1.5v.

terry_seacomp's picture
terry_seacomp
October 22, 2020

@herbroy Great! Glad to hear it worked for you