Hein and Zakhor analyzed the limit-cycle behavior of the low-pass double-lo
op converter. This brief demonstrates that the limit cycles in a bandpass S
igma-Delta double-loop converter are identical to the low-pass case. It is
shown that the double-loop converter can have two independent limit cycles
occurring simultaneously. Simulations confirm that the bandpass converter s
tate variables can be designed to stay within designed bounds, as in the lo
w-pass (baseband) case. Hence, stability is improved as the likelihood of s
tages saturating and clipping is significantly reduced.