Very high dynamic range and high-sampling rate VME digitizing boards for physics experiments

The trend in data acquisition systems for modern physics experiments is to digitize analog signals closer and closer to the detector. The digitization systems have followed the progress of commercial analog to digital converters. The state of the art for these devices is currently limited to 200 MHz, for a 10 to 12 bits range. Faster ADCs, originally dedicated to military applications are also available, but their resolution is lower and they are much more expensive. The new board, described in this paper, has been designed to improve these performances by an order of magnitude. In its simplest version, this board includes mainly 4 channels of 12-bit resolution digitizers sampling analog data up to 2 GSample/s with an analog bandwidth of 300 MHz. It is based on the custom-designed MATACQ chip. Its innovative design allows to reach these performances with a power consumption smaller than 1 W. The boards are triggerable either by internal or external signals and several boards are easily synchronizable. The board integrates both a GPIB and a VME interface that permits a maximum readout speed of 500 event/s with all the memory cells of the 4 channels read. Several other read-out modes allowing to read only a set of limited set of cells or of channels are available for faster operation.