This study demonstrates a current-mode analog-to-time converter (CMATC) enabling short-pulse output capability by using the newly-proposed local intra-cell activation technique, which contributes to the development of high-speed time-domain biosensor array. In the conventional CMATC, the activation pulse is generated globally at the periphery. This limits the output pulse width because of the considerable parasitic word-line capacitance. In this study, a shorter pulse output was achieved by generating the activation pulse locally by using intra-cell configuration without being affected by word-line capacitances. In 1024 × 1024 configuration, 77% pulse width reduction was confirmed using SPICE simulation. A test chip was fabricated using a 0.6 µm standard CMOS process. The measurement results obtained using a sensor chip demonstrate the expected input–output characteristic and 3.36 ns pulse output. Finally, we measure the change in potential with respect to the ratio of the ion concentration, by using Fe(CN) 63− and Fe(CN) 64− as the oxidant and reductant, respectively.