This document is a model and instructions for DTEX. This work focuses on the design of a CMOS DC-DC buck converter targeting input voltages higher than the limited gate-source voltage common in thin oxide technology. This is enabled by driving the power device gates using fully integrated circuitry which allows floating voltages in the high -side device using bootstrapping. The gate driver has been fully characterized in simulation, showing low to high an high to low times below 12ns. The bootstrapped level shifter has been integrated together with a dual-NMOS half bridge using the Skywater 130nm Opensource CMOS technology. Simulations show a peak efficiency of 91 % at 38.2mA current load for a 10V to 3.3V DC-DC conversion, extending the input voltage range previously reported in this technology by 2X.