This work presents a power efficient one-shot rectangular pulse circuit made up of a delayed step pulse generator (MDSPG) followed by a variable rectangle pulse width generator (VRPWG) with auto termination. The MDSPG generates a delayed feedback signal and the VRPWG generates variable rectangular pulse with four different pulse width options. At 90-nm CMOS technology, the design occupies 0.0058 mm2and limits the power consumption between$5.78 \mu \mathrm{W}$to$5.81 \mu \mathrm{W}$at modes M0 and M3, respectively. Additionally, the proposed architecture ensures a large span of rectangular pulse width ranging from$155.66 \mu \mathrm{s}$to$1247.96 \mu \mathrm{s}$at M0 and M3, respectively. The proposed design is a suitable choice for a multi-mode resolution and multi conversion time-domain temperature sensor. A subthreshold time-to-digital converter is accommodated to realize the sensor in a 90-nm CMOS and the area is limited to 0.011 mm2. Lastly, the resolution varies between 0.29° C and 0.036° C at modes M0 and M3, respectively.