A5 Power routing "minor issues" for some modules
Michael Shiloh
michael at openmoko.org
Tue Feb 26 20:25:21 CET 2008
So the battery acts as a large capacitor for instantaneous peaks in
power consumption. Fair enough.
Neng-Yu Tu (Tony Tu) wrote:
> Following link explains why I am so worry about GSM part change. GSM
> might have instant pulse of 2A power consumption.
>
> Standard USB only 500mA max. And the switch has very bad performance
> under low temperature. And for mobile device design, usually it would
> not power up if battery not exist, even adapter with power plugged in.
>
> http://findarticles.com/p/articles/mi_qa3864/is_199806/ai_n8804695
>
> =======================
> Let us look at an example of a GSM mobile unit that transmits at 5.0W,
> but due to internal loss in the phone, 10.84W is required from the
> battery. The GSM mobile unit is a 5V system that has a quiescent current
> of 0.2A and draws 2.17A when transmitting voice or data packets.
> =======================
>
> Tony Tu
>
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