We propose a hierarchical mixed signal design methodology based on the principles of Platform-Based Design (PBD). The methodology is a meet-in-the-middle approach where design components are modeled bottom-up at various abstraction levels and performance constraints are mapped top-down to select among the available components the ones that best meet the constraints. The design methodology can seamlessly operate on both analog and digital designs, thus dealing with mixed signal designs in a consistent way. We demonstrate the effectiveness of the approach optimizing an 80 MS/s 14 bit pipelined Analog-to-Digital Converter (ADC) including digital calibration, yielding 64% power reduction compared to the original hand optimized design. Categories and Subject Descriptors B.7 [Integrated Circuits]: Design Aids General Terms Algorithms