An approach to robust system level mixed signal design is presented based on analog platforms. The bottom-up characterization phase of platform components provides accurate performance models that export architectural constraints to the system level. From the one side, performance models can be affected by residual errors and usually do not consider process variations and modeling uncertainties. Conversely, behavioral models cannot match accurate circuit level simulations, so that during the mapping (exploration) process circuit configurations difficult to be realized may be obtained. We propose a methodology that extends techniques from optimization and design centering to system level analog design exploiting general, implicit architectural constraints to control the robustness of the solution. The approach allows quantitative extension of robust techniques to hierarchical designs. Its effectiveness is illustrated with the design of a pipeline A/D converter and a UMTS receiver fr...