12 comments on “SSD1963 Thoughts

  1. it would be nice to have variable light voltage with simple smd potentiometer, it will add some cost, but that would be nice feature

  2. Yeah i was thinking about that. I never tried to make a MC34063 variable… shouldnt be too hard.
    I think making R2 a variable resistor will do. But what should the max current be ? 20mA – 25mA ?

    • Whats a feedback divider? Heh im smart but dont know everything :)

      Heh scratch that, the feedback resistor to a variable type which is R2… wow i must be tired :)

  3. or another idea, since it will be LED back-light, use constant current driver, no matter what you have, or 7,5V back-light, or 25V, it will work instantly (20mA constant current boost driver).
    argh, so many ideas how to build stuff, but it cost sometimes :(

  4. Yeah, i have no clue how to make a constant current boost tho :( Ill leave it variable and try to make the max output current 20mA so nothing blows up.. :) Or in fact… can i simply add a place holder for a resistor? so user can add there own value for final current… would be cheaper and easier than constant current…

    Like all people should know .. R = V/I so if i need 20mA and i know its spitting out 29v… then: 29v / .02A = 1450… 1.45kOhm or closest is probably 1.5k so with 1.5kohm its i = v/r = 29v / 1500 = .0193A = 19mA

    Linas, ah. I should have guessed… Cool!

  5. It’s same principle as voltage stabilization. all you need is measure voltage which is in series to target GND. lets say you want to make 20mA current stabilization, ok, so you need shunt resistor, 1R will work. so U=I*R=0.02*1=0.02V.
    so you can’t go up 0.02V, but that is problem, because you have 1.25V reference on ic’s, so what you do is using simple opamp you boost voltage from 0.02 to 1.25V ( 1.25V/0.02V= 63x voltage boost )
    that’s it :)
    i don’t know will it work, it’s just theory :)
    Hm, in china for 40$ is possible to get with shipping 4.3″ lcd with SSD1963 and touchscreen driver :(
    But your board would be better for overall testing

      • I fixed/edited the typo for you. Its ok im in US and always mix things up :)
        Your english is actually better than most people.

        Ok i think im starting to understand. I guess i should play around with this theory and see what i can do. Ill need to order the shunt resistor which shouldnt be a issue.

        • 1R resistor will work like a charm, since 20mA is nothing, and power drop is just 0,4mW (good old 1206 will work more than fine, and even here in Lithuania i can buy 1R 1206 0,25W resistor for 0,04$ )
          but you must test it on single side pcb before go to the production of this pcb.
          and in your case i would go to linear ic for voltage/current stabilization, because i like them , you can use simple 10uH inductor ant that would give 29V at high efficiency and low ripple voltage :)

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