SACK V2 test

Carlos Camargo cicamargoba at gmail.com
Tue Jul 27 09:02:06 EDT 2010


>
> .
>
> Here's my comments:
> a) Are you really need a 64MB 512Mb SDRAM? Why not 32MB same as BEN? Surely
> we know the bigger the better. Pls see its cost carefully.
>

It doesn't matter  32MB is good, we can provide both option if the customer
want more RAM, but for this first run 32MB is fine.


> b) Parts:
>   1, D10, from http://en.qi-hardware.com/w/images/b/bf/SAKC.jpg, seems you
> removed the diode on the led drive board I sent to you then soldered on V2
> board. You can check and try to use MSCD104H used on BEN or AVT2. I filled
> it in "Substitution P/N" column.Check it if it can meet your footprint.
>

I've already change D10 footprint to fit QI's inventory



>   2, C15, 10nF on schematic, you want it 100nF or 10nF?
>

C15 value came from reference design, If you want to change it no problem.




>   3, R2, 2.5k/1% on sch.; actually it will be mounted a 2.49k/1%.
>

The right value is 2.5k but I don't have this value I've mounted a near
value.



>   4, Y3, it's FXO-HC536R-50 (5.15mm * 3.35mm) on bom, but should use
> FXO-HC736R-50 (7.5mm * 5.2mm) to meet your footprint. I suggest that we can
> use smaller one: SO5032-050000-O3A-BBE-QA  which is used on Milkymist One
> even later Xue.
> http://downloads.qi-hardware.com/hardware/sakc/datasheet/Y3~SO5032-050000-O3A-BBE-QA~NOT_FINAL.pdfif later having V3.
>


If the footprint and the frequency (50MHz)  is the same you can change it,
no problem, I can't access download server thsi week, so I can't check the
oscillator size.



>   5, C69, C71: according to
> http://downloads.qi-hardware.com/hardware/qi_avt2/v1.0/datasheet/LCM~GPM940B0-SPEC_A_2009.01.13~~FINAL_LCM-NOT_ON_SOME_PROTOTYPES~~.pdf, those two are suggested to be 4.7uF/25V, but they are all changed to
> 4.7uF/16V. You can easily check those body color are likely different on
> BEN's led driver board compared to others capacitors. I'll directly change
> them later.
>

I'm recycling all LCD's circuit for black LCM sent by you, if you want to
make any change here no problem.



>   6. J6/J7/J18: those three actually can combine into one part MD241845<http://www.stm.com.tw/test/pdf-1/c24184.pdf>as listed.
>




>   7. D8/D9: CDBU0130L<http://www.comchip.com.tw/cms/UserFiles/QW-A1107-CDBU0130L-RevA134692.pdf>this Schottky Barrier Diode 100mA 35V, if you don't insist, pls ref. to use
> MSCD104H same as AVT2 & BEN.
>

No problem



>   8. 10V, 10uF, 10%: I use TANTALUM capacitor (our inventory) instead of
> MLCC.
>

No problem



>   9. L13: I'll temporarily use PI0302-4R7M if I don't have it before smt.
>

I'll change the footprint to fit the PI0302-4R7M.



>   10. R34: once you finish test charge function, pls tell me the value.
>

Right now I don't have batteries, my students will make this test :)


>
> c) Layout:
>    1. J20: LCM FPC connector, As same Wolfgang questioned its orientation
> previous reply.
>

The current orientation is good don't change.


>    2, L12: let it not close to U11 body.
>

ok



>    3, J19: mark "J19" reference on silkscreen.
>

ok




Best Regards


Carlos



-- 
Carlos Iván Camargo Bareño
Profesor Asistente
Departamento de Ingeniería Eléctrica y Electrónica
Universidad Nacional de Colombia
cicamargoba at unal.edu.co
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