The temporal phase modulation class of interferometers is known to be able to provide high-accuracy measurements of displacement. The resolution of this class of interferometers is studied in relation to its application in atomic force microscopy under the static deflection mode. Interferometric sensing is advantageous if atomic force microscopy is implemented for array cantilevers. The sources of error are assumed to be either additive (due to noise in photodetection and in the electrical circuitry) or multiplicative (due to ambient effects). We reveal that minimum detectable displacements in the 0.1-nm range are possible under very careful design and measuring conditions.