Mu3e is an upcoming experiment searching for charged lepton flavor violation in the rare decay mu->eee. A silicon pixel tracker based on 50um thin high voltage monolithic active pixel sensors (HV-MAPS) in a 1T magnetic field will deliver precise vertex and momentum information as well as a time resolution of below 20ns. The HV-MAPS chip developed for Mu3e, the MuPix, combines pixel sensor cells with integrated analog electronics and a complete digital readout. The full integration of pixel sensor, analog and digital electronics into a 50um thick chip allows for detector designs with a tracking layer thickness of just 0.1% of a radiation length X0. In the recent years a series of MuPix chip prototypes have been developed and tested both in the laboratory and at test beams successfully.
Results from the characterization of the first large scale MuPix prototype will be presented.