Does anybody know the Mpxh6115a sensor?

Hi.. Does anybody know if I can use the Mpxh6115a with my arduino by just connect it or need some extra device?

That's a barometric sensor ultra sensible. That is used in flight tech variometer...

Any idea?

The data sheet says that the output is 0.2 to 4.8Vdc so you can directly connect to an analog input with the analog reference at 5Vdc. If you need high accuracy you will need a more stable and accurate reference as the 5V reference is dependent on supply voltage.

In general it is wise to google for the datasheet and read it, one quick look at Figure 3 should
reassure you it just connects to an analog pin... http://www.freescale.com/files/sensors/doc/data_sheet/MPXA6115A.pdf

But you'll only get 10 bit precision, its not clear how much precision is needed to get
the most from the device. (some digital pressure sensors provide 19 bit ADC on chip,
for instance).

Given my aggravation at getting I2C to work with Freescale pressure sensors, I can recommend a device with analog output. But the effective resolution isn't all that good.

I've used the SCP1000 before, its SPI and very sensitive (resolution 1.5Pa) but only 3.3V
supply. And yes it takes a little figuring out compared to analog, but the performance is
awesome.