An example a semiconductor device includes a first circuit and a second circuit formed in a semiconductor substrate. The semiconductor device further includes a first guard structure formed in the semiconductor substrate and disposed between the first circuit and the second circuit, the first guard structure including first discontinuous pairs of n+ and p+ diffusions disposed along a first axis. The semiconductor device further includes a second guard structure formed in the semiconductor substrate and disposed between the first circuit and the second circuit, the second guard structure including second discontinuous pairs of n+ and p+ diffusions disposed along the first axis, the second discontinuous pairs of n+ and p+ diffusions being staggered with respect to the first discontinuous pairs of n+ and p+ diffusions.