The most striking feature of BTeV, a dedicated b physics experiment which is expected to begin running in 2008 in the new CZero interaction region of the Fermilab Tevatron, is that the experiment will use data from a pixel vertex detector to recon- struct tracks and vertices for every beam crossing. The lowest level trigger will be an impact parameter trigger designed to identify events containing reconstructable decays of charm and bottom particles. An R&D program to develop a pixel readout chip optimized for the Tevatron was started at Fermilab in 1997, and is now nearing completion. The architecture of the BTeV pixel readout chip is described in this paper.