SACK V2 test

Carlos Camargo cicamargoba at
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, 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

>   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.
> 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
>, 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<>as listed.

>   7. D8/D9: CDBU0130L<>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

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.


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


Best Regards


Carlos Iván Camargo Bareño
Profesor Asistente
Departamento de Ingeniería Eléctrica y Electrónica
Universidad Nacional de Colombia
cicamargoba at
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