We report on an integrated acousto-optic filter in domain inverted LiNbO3 using a coplanar electrode configuration, which can achieve complete optical switching at electrical powers as low as 50 mW. These values are more than one order of magnitude lower than previously reported results [Opt. Lett. 34, 3205 (2009)]. In order to design the low power consumption devices, we have calculated surface acoustic wave excitation, propagation and acousto-optic interaction in the domain inverted LiNbO3 superlattice using scalar approximation and FEM analysis. Results from both modeling techniques are in good agreement with the experiments, including direct measurement of the acoustic displacement using laser interferometry and acousto-optic performance.