[gta02-core] ECN0010 (Audio amp)

Rene Harder rehar at saweb.de
Wed Oct 7 19:23:57 CEST 2009

Werner Almesberger wrote:
> This one also looks as if it's getting ready for closing. A few
> observations, mainly just documentation problems:
> - "Removing the external amplifier (U4101) as well as the amplifier
>    specific components R4114, R4112, R4109, R4108, R4110, R4113, C4117,
>    C4111, C4110, C4110 and C4115."
>   This seems confused. Twice C4110 ? C4110 and C4111 are still around.
>   I think this should be C4114, C4115, C4117.

Yes indeed that sounds confusing and of course we need to keep the dc
blocking caps C4110 & C4111.

ECN changed, also added R4115!

>   Also, R4115 is missing. Maybe we could also add a word of explanation
>   for each of the components, e.g., R4110 and R4113 (input), R4112 and
>   R4115 (feedback), R4109 and R4114 (pull-up), R4108 (supply), C4114
>   and C4115 (input decoupling), C4117 (bypass).

Do you think that is really necessary if they get removed anyway?

> - "The external headphone will be connected between ROUT1 and LOUT2"
>   should be LOUT1, right ?

> - didn't we talk about merging the 18+39 pF caps into 56 pF caps ?
>   (C4120 + C4119 and C4121 + C4122)
>   Might as well do this as part of ECN0010.

This is taken care of in ECN0038.

> - The B4102 story is confusing. We might just skip the intermediate
>   step, and refer directly to ECN0032.

I deleted the sentence and keep only the reference to ECN0032.

Thanks for the review,

More information about the gta02-core mailing list