Abstract:HDY-402 tri-frequency airborne electromagnetic instrument which is independently reasearched and developed by institute of geophysical and geochemical exploration,CAGS,is the airborne electromagnetic measurement system with China-only intellectual property rights,is mainly used for mineral exploration,water resources survey,seawater intrusion investigation and other fields. In this article I will detail the features and functionality of LTC1605 which is a 16-bit A/D converter made by Linear Technology corporation,and its application in HDY-402 System.