In this paper, we present an integrated circuit designed for photomultiplier tube (PMT) pulse processing. This circuit was developed for the RICH detector of the AMS experiment. It integrates 16 identical channels and has to deal with space environment constraints (low power consumption, radiation hardness). It processes the 16 analog signals coming from anodes of a multianode PMT and the signal coming from a dynode. It integrates a control logic for the multiplexing of the output data. A test mode can be activated for the calibration of each channel. An offset cancellation system has been designed for the dynode channel. This offset cancellation is important in order to avoid thermal drifts and offset spreads.