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Sony ACX705AKM LCD users/ spec questions?

Started by Bo March 8, 2006
We are planning to use this LCD in an embedded project with a Gumstix 
processor and I am having more than a little trouble getting support from 
Sony.

The 1st problem is knowing how to drive the LED backlight.

The spec simply says 15mA current source, but it does not give any details 
about the forward drops in the backlight. So I don't know what the minimum 
voltage is.

If anyone has used this LCD successfully and can provide details on how to 
drive the backlight I would be grateful. I would like to drive it from my 5v 
switcher if possible--or raw Li Ion 8.4v if 5v is insufficient. If 8.4 isn't 
enough, guess I'll be adding another switcher.

Also, the spec is ambiguous (I'm being generous here-- it actually has no 
info) as to the logic levels expected on the S/D pin.

The spec is here:

http://www.sony.net/Products/SC-HP/cx_news/vol21/pdf/acx705.pdf

Suggestions? (other than contact Sony--- the have no tech support folks/FAEs 
and even trying to find a direct support phone number has been fruitless).


Thanks,

Paul



Bo wrote:
> We are planning to use this LCD in an embedded project with a Gumstix > processor and I am having more than a little trouble getting support from > Sony. > > The 1st problem is knowing how to drive the LED backlight. > > The spec simply says 15mA current source, but it does not give any details > about the forward drops in the backlight. So I don't know what the minimum > voltage is.
My guess is 50V (0.75W) to 100V (1.5W).
> > If anyone has used this LCD successfully and can provide details on how to > drive the backlight I would be grateful. I would like to drive it from my 5v > switcher if possible--or raw Li Ion 8.4v if 5v is insufficient. If 8.4 isn't > enough, guess I'll be adding another switcher.
5V will give you 0.075W, just a little better than no light. You need to look for a step up DC/DC.
> > Also, the spec is ambiguous (I'm being generous here-- it actually has no > info) as to the logic levels expected on the S/D pin. > > The spec is here: > > http://www.sony.net/Products/SC-HP/cx_news/vol21/pdf/acx705.pdf > > Suggestions? (other than contact Sony--- the have no tech support folks/FAEs > and even trying to find a direct support phone number has been fruitless). > > > Thanks, > > Paul
On Wednesday, in article
     <966f4$440f0348$18d6ec55$12527@KNOLOGY.NET> bo@cephus.com
     "Bo" wrote:

>We are planning to use this LCD in an embedded project with a Gumstix >processor and I am having more than a little trouble getting support from >Sony. > >The 1st problem is knowing how to drive the LED backlight. > >The spec simply says 15mA current source, but it does not give any details >about the forward drops in the backlight. So I don't know what the minimum >voltage is. > >If anyone has used this LCD successfully and can provide details on how to >drive the backlight I would be grateful. I would like to drive it from my 5v >switcher if possible--or raw Li Ion 8.4v if 5v is insufficient. If 8.4 isn't >enough, guess I'll be adding another switcher. > >Also, the spec is ambiguous (I'm being generous here-- it actually has no >info) as to the logic levels expected on the S/D pin. > >The spec is here: > >http://www.sony.net/Products/SC-HP/cx_news/vol21/pdf/acx705.pdf > >Suggestions? (other than contact Sony--- the have no tech support folks/FAEs >and even trying to find a direct support phone number has been fruitless).
Do you have a variable bench supply with a settable current limit? Also with current metering? Set current limit to something like 12mA, slowly and carefully bring power up from 0V to about 3V and note current drawn and work it out for 5V or what ever it is and do CAREFUL experiments. -- Paul Carpenter | paul@pcserviceselectronics.co.uk <http://www.pcserviceselectronics.co.uk/> PC Services <http://www.gnuh8.org.uk/> GNU H8 & mailing list info <http://www.badweb.org.uk/> For those web sites you hate