[gta02-core] GTA02 GPS chip (ATR0635) VDD 1.8 power rail

Werner Almesberger werner at openmoko.org
Sat Jul 4 23:19:26 CEST 2009

Rask Ingemann Lambertsen wrote:
>    Add a FET or another RT9702APB between IO_1V8 and GPS VDD18, gated by
> RF_3V?

I still wonder if the GPS subsystem doesn't have a suitable
software-activated power-down mode already, i.e., the "Sleep State"
and the "Backup State". You wake up from them via a hardware signal
(EXTINT or reset, respectively), so it does seem rather low-level.

Adding switches to cut power is rather brute-force and it may have
unintended consequences, such as current creeping in over other
paths, and loss of "expensive" internal state.

- Werner

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