The measurement of the magnetic field vector is of fundamental importance to space physics missions. The fluxgate magnetometer is a device developed for precise vector measurement of static magnetic fields. The high performance magnetometers are required in such NASA missions as ICON, GOLD, Solar Orbiter, Solar Probe Plus, ONEP, SEPAT, INCA, CISR, DGC, HMag and other planetary explorations. The analog-to-digital converter (ADC) is one of the critical components of the magnetometer. The performance of the magnetometer directly depends on the ADC's characteristics such as the resolution, accuracy, and conversion speed. The general requirements for all ADCs used in space missions are low power consumption, low area, and high radiation tolerance. Pacific Microchip Corp. proposes to develop a rad-hard ADC specifically targeted for application in Fluxgate Magnetometers. Phase I work provided a proof of feasibility, complete definition and validation based on extensive simulation and analysis of the proposed ADC. During Phase II the ADC design will be finished, the ADC will be fabricated, packaged and tested (including radiation hardiness). At the end of Phase II a fieldable product will be produced. In order to facilitate the commercialization efforts in Phase III, the product will be fabricated using a commercial 180nm CMOS technology.