Recommendations for replacing pot for production.

[blak3r]

For production, i would like to replace the contrast adjust pot with two discrete resistors to eliminate an extra step in assembly.

I was wondering if there were any recommendations for discrete values. I have experimentally determined that i want a Vo pin voltage of approx 0.9V and have found using 4500Ohm and 500 Ohm resistors will work.

But, before i commit to doing a run with these i was wondering if there were some recommended values which provide best contrast with respect to other manufacturing tolerences within the lcd.

Vdd = 5V
LCD = CFAH2004

Crystalfontz LCD Blog

Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.

 

[CF Tech]

We typically recommend a 10K pot, so something like a 1800+ 8200 might work well.

If your supply can vary, or if the device will be operated over wide temperature swings, or if the viewing angle will change, then a pot might be better.

We recommend that you use a pot, and have a tech adjust it for optimal viewing at final test. Sometimes different batches of LCD glass might have slightly different sensitivities, and need different voltages. Additionally, a pot gives your production flexibility in case a substitution of LCD has to be made.