tailieunhanh - Model-Based Design for Embedded Systems- P65

Model-Based Design for Embedded Systems- P65: This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. | 626 Model-Based Design for Embedded Systems TABLE Optical Device Parameters Source Parameter Min. Value Max. Value Units Total efficiency mW mA Area 10 x 10 100 x 100 . . 2 m Threshold current A Bandwidth 10 GHz Detector Responsivity mA mW Area 10 x 10 100 x 100 2 m2 Capacitance 1e-15 1e-13 F Dark current 1e-18 A Noise current 1e-15 A Bandwidth 20 GHz Waveguide SOI SÍ3N4 Guide index Cladding index Height im Width l m Pitch 4e-6 m Loss dB cm Delay ps mm Excess bend loss dB 90 Bend radius 2 10 im transmitter and receiver circuits modulate laser current and transform detector current respectively through a via stack as represented by Rvia in Figure . Light emitted by an InP laser is transported through a passive Si SiO2 structure at wavelengths around gm to an InP or SiGe detector. In this design approach no architectural variants are considered . the CMOS topologies used at the transistor level are fixed in terms of their structure the variables for the design problem consist essentially of bias currents and transistor sizes . The synthesis approach implemented consists of creating scenarios allowing the specification of each model via a generic class containing all structures to be optimized as well as necessary evaluation and design methods Figure . Communication between the different blocks is ensured using the synthesizable AMS MT IP blocks and the actual synthesis and evaluation scenario relies upon the instantiation of the generic top-level object in a testbench structure. A device library containing the synthesizable models of each device in the optical link based on the UML language was developed to allow the modeling of this hierarchical synthesis problem as was already shown in Figure . The procedure used to automatically synthesize an optical point-to-point link and implemented as a synthesis scenario is shown in Figure . The