The modeling methodology of power distribution system (PDS) in three different levels, chip, package, and PCB for Input/Output (I/O) interface of DDR3 high-speed memory is established. The simulation results are verified with measurement results in frequency domain. Good agreement between them is clearly seen. The co-simulation with three kinds of PDS at the I/O interface and off-chip driver (OCD) circuits is constructed for time-domain simulation. The input impedance of three different PDSs is shown, and the simulation results for voltage variation and eye-patterns are compared with the corresponding input impedance. It is found lower input impedance have better power and signal integrity for the high-speed memory interface circuits. The PDS co-simulation of chip-package-PCB is important for the DDR3 circuit design.
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