  Using industrial standard 0.35{\mu}m CMOS Integrated Circuit process, we
realized a highly pixelated sensor that directly collects charge via metal
nodes placed on the top of each pixel and forms two dimensional images of
charge cloud distribution. The first version, Topmetal-I, features a 64x64
pixel array of 80{\mu}m pitch size. Direct charge calibration reveals an
average capacitance of 210fF per pixel. The charge collection noise is near the
thermal noise limit. With the readout, individual pixel channels exhibit a most
probable equivalent noise charge of 330e-.
