I'm looking to minimize sleep (off-mode) power usage on my
Beagleboard. From the software side of things, I'm working to get
regulators turned off and or set to sleep mode during sleep. But on
the board, there are a few things that consume quite a bit of power
even during sleep.
The Y1 oscillator (EP16E7E2H-26.000M_TR) uses 9mA@1.8V (16.2mW). It
has a power down mode, but the pin isn't connected to anything, and
anyway, it only gets it down to 4mA. It'd be ideal to connect the
power down pin to the CLK_EN of the TWL4030, but that pin isn't
brought out. So I'd like to connect it to another controllable pin.
I'd also like to replace the oscillator with something that has a
lower sleep mode power consumption. There is a variant of the EP16
that has a power down mode that only draws 30 microamps in power down
mode (EP16E7E2J), but I can't find it available anywhere. The Y1A part
(SG-210SEB 26.0000MF) has much lower power consumption and a low sleep
consumption. Does anyone know of a source where I can get small
quantities of either part?
Other things that consume power that I'm just rambling about...
The TFP410 uses up to 0.5mA@3.3V (1.6mW) during power down mode and
the RS232 transceivers use up to 1mA@3.3V (3.3mW). The transceivers
don't have the FORCEOFF pin tied to a controllable input. I'd like to
hook up the LDO_EN pin of the 3.3V regulator to a GPIO so that I can
power if off during sleep.
The power LED uses 10.6mA@4.2V (44.52mW). I'd like to move that over
to the 3.3V rail so that it turns off with the 3.3V rail.