Patent ID: 7683675
Filing Date: 2010-03-23
Classification: H03D

Abstract:
1. A radiation hardened phase frequency detector (PFD) for implementing enhanced radiation immunity performance comprising: a plurality of functional blocks; each said functional block including duplicated components providing duplicated inputs, and duplicated outputs; said plurality of functional blocks including a plurality of radiation hardened latches, each radiation hardened latch including said duplicated components providing said duplicated inputs, and said duplicated outputs; said plurality of functional blocks including a plurality of logic gates, each logic gate including duplicated inputs, and duplicated outputs; said plurality of radiation hardened latches including a first pair of said radiation hardened latches coupled to respective logic gates and a second pair of said radiation hardened latches, each said first pair of radiation hardened latches receiving identical PFD input signals and providing duplicated output signals; each said second pair of said radiation hardened latches receiving duplicated output signals of a respective one of said first pair of radiation hardened latches, and respectively providing duplicated PFD increment output signals and duplicated PFD decrement output signals; said duplicated components being arranged for a single event upset (SEU) hit to one node, a duplicated node supporting the functionalities of the phase frequency detector (PFD).