Critical block analysis for the transfer, gain and phase functions in multiple-loop feedback networks

Measures for determining the most and least critical blocks in multiple-loop feedback networks are defined for the transfer, gain and phase functions. Simple and systematic procedures for computing their values, thus determining the ordered hierarchy of critical blocks, are provided. The knowledge of the most and least critical blocks is shown to provide useful guidance for modifying component tolerances to produce higher yield or lower component costs. The tolerance assignment procedure described differs from those described elsewhere in that multiple component tolerances are assigned simultaneously on a block-by-block basis.