DA conversion device and electron beam exposure system using the same

摘要

A DA conversion device includes a current output type DA converter, a high-speed operational amplifier operating at a low voltage and configured to generate a voltage corresponding to an output current from the DA converter, and a buffer amplifier connected to an output terminal of the high-speed operational amplifier and operating at a high voltage. The device also includes positive and negative floating power supplies separated from a power supply system and provided as power supplies for driving the DA converter and the high-speed operational amplifier. A midpoint between potentials at the floating power supplies is connected to an output terminal of the buffer amplifier to cause the DA converter and the high-speed operational amplifier to operate mainly based on an output voltage from the buffer amplifier.