Design Of AC/DC Power Management Ic Based On BCD Technology

Within the wide family of Switch Mode Power Supplies (SMPS), the flyback converter, with the advantage of high-efficiency, low-power, topological-simplicy, isolation, low-cost, represents the preferred structure for use in small and medium power applications such as adapters, off-line battery chargers, fax machines, etc. So it is of great theoretical significance and pratical value to do rearch on the flyback AC/DC Power Management Integrated Circuit (PMIC).The design and implementation of a new prime-side flyback AC/DC PMIC is presented in this thesis. Unlike conventional PWM or PFM modulator, it regulates the output voltage in a new method of off-time modulation by controlling the off-time of the switch transistor. The SMPS operate in DCM employing the chip with constant voltage (CV) and the constant current (CC) function. The output voltage of the SMPS using the PMIC is ajusted according the variation of the load sensed by the auxiliary winding. And the optocoupler can be cut off in the small power circuit. So the application of the system is simplifized and the cost is reduced effectively.It studies the design of the chip and the process information of the BCD offered by the foundry at first. Based on the analysis of the main module circuit, the design of the whole circuit is completed in this subject. Finally, the layout of the PMIC is implemented in the 0.5um BCD process.The circuit is analyzed and simulated with Spectre program and model file provided by the foundry. Using the layout edit tool Virtuso, the layout is implemented. And the layout is verified by the layout verification tool Dracula. The chip is successful tapout in MXIC. The simulation result and the test data show that the specification of the design are met, and the chip can be reliable and effective work, and the output power of the application circuit of the chip is up to 5W, and the efficiency achieves 80%, which satisfy the design requirements. That verifies the validity of the theoretical analysis and the practicality of the design.