[gta02-core] ECN0010 (Audio amp)

Werner Almesberger werner at openmoko.org
Wed Oct 7 02:26:30 CEST 2009

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.

  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).

- "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.

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

That's all I found.

- Werner

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