I have an application that is sensitive in both resolution and power consumption.
The MPL3115 gives me sufficient resolution at an oversampling ratio of 128x, but the power consumption is too high. On the other hand, the "highest speed mode" (oversample ratio of 1x) is well within my power budget, but I'm worried the resolution will no longer be sufficient.
Unfortunately, the datasheet is silent on these relationships.
In the end, of course, I'll have to fine-tune the balance with empirical testing, but I'd like to get a better feel for how this will work before committing to the MPL3115 in my design.
Is there any documentation on how the MPL3115 behaves under other oversampling ratios?
(p.s. I'll be using both altimeter and barometer modes)
I understand your concern, but unfortunately we do not have a document that mentions the trade-off between resolution and power consumption using oversampling for this device (we have an application note for the same question but for our accelerometers: http://cache.freescale.com/files/sensors/doc/app_note/AN4075.pdf)
Power consumption and sensitivity are programmable where the data oversampling ratio can be set to balance current consumption and noise/resolution.
The data-oversampling ratio can be set to balance current consumption and resolution. Typical active supply current is 40 µA per measurement-second for a stable 30 cm output resolution. It is ideal for portable applications when the sensor operates at 8.5 µA in low-power mode at 1 Hz.