Pseudorandom pulse generator for a uniform amplitude distribution with discrete lines

Abstract

For calibrating and testing pulse height analysing equipment a generator was built supplying a uniform pulse height distribution superposed by one valley and 2 n −2 peaks or one peak and 2 n −2 valleys ( n =1, 2, 3…). The distribution is produced by a 12 bit DAC which is controlled by pseudorandom binary numbers being the sum of a 12 bit linear feedback shift resister and a binary counter, the carry bit being suppressed. In the sequence of these binary numbers special jump heights dominate. When the DAC is followed by a lead network the special jump heights generate shift of 2 blocks of the uniform distribution in such a manner that a gap opens in the middle of the distribution, while the superposition of the other block limits yields peaks. The inherent differential nonlinearity of the DAC is nearly completely blurred by the lead circun. Using a lag network, peaks are changed into valleys and the middle gap becomes a peak.