Characterization of the AGIPD1.1 readout chip and improvements with respect to AGIPD1.0

AGIPD, the Adaptive Gain Integrating Pixel Detector, is a hybrid detector with a frame rate of 4.5 $MHz$, a dynamic range up to $10^4\cdot$ 12.4 $keV$ photons, as well as single photon resolution, developed for the European XFEL (Eu.XFEL). The final 1 Mpixel detector system consists of 16 tiled modules each one with 16 readout chips. The single ASIC is 64 x 64 pixels, each with a size of 200 x 200 $\mu m^2$. Each pixel can store up to 352 images. This work is focused on the characterization of AGIPD1.1, the second version of the full scale ASIC, and the improvements with respect to AGIPD1.0. From the measurements presented in this paper we show that the flaws observed in AGIPD1.0 (i.e. ghosting, crosstalk, slow readout speed) have been fixed in AGIPD1.1. In addition the main performance parameters such as noise, dynamic range and so on were measured for the new version of the ASIC and will be summarized.