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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