Fuse circuit designs and the use thereof are disclosed. In one example, a
fuse circuit providing predictable total resistances for multiple rounds
of programming comprises a predetermined number of fuse stages coupled in
series. Each stage comprises a first and a second connecting nodes, a
fuse connected between the first and second connecting nodes, a first
resistor with its first end connected to the first connecting node, and a
second resistor with its first end connected to the second connecting
node, wherein the first and second resistors connect to a third and a
fourth connecting nodes, which are the first and second connecting nodes
of a next fuse stage respectively, through their second ends.