A delta-sigma converter has coarse and fine ADCs, wherein an integrated
error signal is coupled to the coarse ADC whose output drives a DAC to
create feedback that achieves loop balance. The coarse ADC provides the
most significant bits of the result. The integrated error signal is also
applied to a fine ADC whose output bits are not incorporated into the
feedback, but which are combined with those of the coarse ADC and the
combination applied to a filter that averages the hunting that represents
loop balance. A DC feed forward circuit shunts the integrator with a
replica of the applied input signal to apply it to the coarse ADC through
a summer, allowing its output to be just the integrated error signal
without including the applied input. If continuous integration is used,
an AC feed forward circuit provides a compensatory voltage that is
removed from the integrator output (or alternatively, is added to its
input) and that corrects for a frequency dependent error.