Catalyzes specifically the NADPH-dependent reduction of coenzyme A disulfide. 2 CoA + NADP(+) = CoA-disulfide + H(+) + NADPH Binds 1 FAD per subunit. Homodimer. Contains 2 FAD binding domains and a single NADPH binding domain. Reduction of disulfides occurs by a thiol-disulfide exchange reaction, but involves only a single catalytic cysteine residue that forms a stable mixed disulfide with CoA during catalysis. Belongs to the class-III pyridine nucleotide-disulfide oxidoreductase family.