Patent ID: 8514119

Claim:
A voltage-level converter in a digital-to-analog converter, comprising: a switch turned on or off by an input signal changing in a first voltage range, the switch configured to generate an intermediate signal changing in a second voltage range, the switch comprising a plurality of thin-oxide metal-oxide-semiconductor field-effect transistors (MOSFET) connected in series between a voltage source of a first voltage level and another voltage source of a second voltage level lower than the first voltage level; a capacitor having a first conductor connected to the switch to receive the intermediate signal and a second conductor connected to an output of the voltage-level converter, the capacitor configured to store electric charge and generate a converted signal at the second conductor responsive to receiving the intermediate signal, the converted signal changing in a third voltage range having a highest voltage level and a lowest voltage level lower than the highest voltage level by a voltage difference between the first voltage level and the second voltage level; and a refreshing transistor coupled to the capacitor and configured to periodically refresh electric charge stored in the capacitor.