RE: Simple analog signaling for an AC adapter
Coming from ODM point of view, the digital communication cost will disappear
fast than you expect. Most of the power adapter today already include
digitally control IC. Adding an interface of digital communication channel
may increase small $ in the beginning but will disappear once healthy
competition starts.
Analog way is a bigger problem as it creates testing requirement for
production line and room for error.
Leonard
-----Original Message-----
From: upamd@xxxxxxxx [mailto:upamd@xxxxxxxx] On Behalf Of Tomlins, Garry
Sent: Wednesday, December 08, 2010 8:20 PM
To: Piotr Karocki; upamd@xxxxxxxx
Subject: RE: Simple analog signaling for an AC adapter
I agree with Lee and Arjan:
This is heading down a path of unnecessary and complex functionality that
leads in turn to a complex and expensive implementation. I beleive it will
not be attractive to the major equipment ODM's who will need to adopt this if
it is to be a success.
We should have a simple analog low cost option.
In my experience in servicing the adapter market for high volume electronics
adding a pin, a wire, a resistor a pin to an IC is a big deal - let alone a
separate communications system!
My vote is for a simple analog option as described. I believe this will have
a good chance of adoption and would be a success for the project.
Garry
Texas Instruments (Cork) Limited, Registered in Ireland under Registration
Number: 294554, Registered Office: Riverside One, Sir John Rogerson's Quay,
Dublin 2
-----Original Message-----
From: upamd@xxxxxxxx [mailto:upamd@xxxxxxxx] On Behalf Of Piotr Karocki
Sent: 08 December 2010 11:50
To: upamd@xxxxxxxx
Subject: Re: Simple analog signaling for an AC adapter
I don't agree with Arjan.
We could either "describe current situation" or "shape the future".
Our standard could allow resistor-based "communication", something,
something, and full communication (required voltage etc.).
But as one of goals is to allow to connect every device to every supply (and,
in near future, connections in form of grid; power hubs, power storage etc.),
every supply has to have full communication option. Making provision to
understand simpler communication (as resistor based) makes supply more
costly.
Say, we have hundred million devices. Half of them - resistor based
communication, and tenth of them - full model of communication (4/10 of them
some 'in-between' form).
Or, we could force whole 100 000 000 devices to have full model of
communication.
But it is the only way to make this full communication cheaper - as it would
be "more mass" production. It would be ONE standard...
And the only way to make possible to connect device from 2010 to power supply
from 2050 or vice versa. This scenario is not impossible - when standard
becomes "grid version"... How often you change wiring in your house?
________________________________
From: upamd@xxxxxxxx [upamd@xxxxxxxx] On Behalf Of arjan strijker
[arjan.strijker@xxxxxxx]
Sent: Wednesday, December 08, 2010 12:26 PM
To: Atkinson, Lee; Bob Davis; upamd@xxxxxxxx
Subject: RE: Simple analog signaling for an AC adapter
I agree with Lee that UPAMD should also support low cost devices.
A simple resistor to ground inside the device could tell the adapter what
voltage it requires.
More sophisticated device can still do power negotiation etc.
With regards,
Arjan Strijker
From: upamd@xxxxxxxx [mailto:upamd@xxxxxxxx] On Behalf Of Atkinson, Lee
Sent: Wednesday, December 08, 2010 12:08 AM
To: Bob Davis; upamd@xxxxxxxx
Subject: Simple analog signaling for an AC adapter
Bob, here is a quick presentation on the method that HP uses for
signaling from the adapter to the notebook. We've had this system in place
since 2005 or 2006, and have shipped maybe close to 150million systems that
use the common "HP Smart" system (including notebooks, all in one desktops,
and small form-factor desktops).
My suggestion is that we at least baseline a system that will allow some
scalability of the communication method; at least, allow very low cost
devices to connect to a UPAMD power source and work reliably even if their
functionality is limited. I'm not sure that a lot of simple devices that
would use UPAMD have a need for all the messages that the adapter could
provide, or would be able to negotiate variable power consumption. I think we
all agree, there is very little precedence for using sophisticated signaling
in the common DC powered devices now in the market. Though I agree the simple
methods are limited, if we can deliver a scalable solution there will be
fewer reasons for the industry to not adopt UPAMD.
Thanks again--Lee
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