Hall Effect Sensor Help

[bhorobec]

Hi,

I'm working on a project where I must sense the rotational position of a magnet which is placed around a PCB. The magnet is polarized diametrically and the PCB is placed so its plane is parallel with the magnet's plane of rotation (see photo).

My original idea was to use 2 sot-23 hall sensors, positioned 90 degrees apart which could sense the x and y components of the field from the magnet. These signals would be fed into a microcontroller, to calculate the angular position of the magnet.

I've run into a bit of a snag, where all the hall effect sensors I've been able to find only sense the component of the magnetic field which is perpendicular to their top surface, not parallel, which means they won't sense the magnet's position at all.

Is anyone aware of a hall sensor (preferrably in a sot-23 or similar SMD package) which could do what I need? I am aware that there are many sensors in TO-92 like packages which would work, but I would much prefer SMD.

Also, I've seen some single chip solutions such as this:
http://ca.mouser.com/ProductDetail/ams/AS5601-ASOM/?qs=sGAEpiMZZMu5vlrqIFXt5R6ZCNFfpMv6e%252bGA%2fic6dhn4cek6HjdixA%3d%3d
The problem here is that it must run off of an unregulated rechargable li-ion cell (2.8 - 4.2V) and none of the chips I've found can fit that bill.

Thanks in advance for your help.

[jt]

Maybe this?  (link downloads .pdf data sheet)
http://www.melexis.com/Asset/Datasheet-MLX90360-DownloadLink-5989.aspx

I've worked with it (or something very similar) in the past and it is a pretty neat device.