Design Of AC-DC Power Supply Management Based On The Primary-side Feedback

The power supply plays an important role in people's daily life and work. However, the demand for electronic products increases with the rapid development of science and technology. Since people on the low-carbon era is making great efforts to promote the social concept of environmental protection, new energy-saving, high efficiency power supply will meet the pulse of the times. Due to its excellent properties, the switching power supply will replace the traditional linear power supply and become the main stream in the power supply.The economize on energy AC/DC power management chip is designed based on the specific projects in this thesis. The power management chip operates based on the primary side feedback single-ended flyback, isolated, current PWM modulation principle. The power does not need the photoelectric coupler, precision voltage source TL431 and X/Y capacitance. Thus the system cost is reduced. The chip is widely used in battery charger, power adapter and low power, economize on energy occasion. The main circuit chip circuits include a bandgap reference circuit, OSC circuit, PWM Generator and so on. The chip integrated clamp, over-voltage protection, soft-start, leading edge blanking, software drivers and other auxiliary control circuit are adopted to mate the system stable and the work secure. Firstly, the working principle of the system is analyzed, and the main functions circuits are analyzed. The main circuits are simulated and analyzed with cadence software. Then, the function and the typical performance parameters of the overall circuit are simulated. The results show that the chip has a fixed frequency 50KHz, at light load conditions the state can enter the burst mode, and quiescent current is only 20μA, the standby power consumption is about 200μW.The layout design and the layout checking are accomplished based on LITEON1.0μm SPDM40V-40V high-voltage BiCMOS process. Finally, the fabricated chip is tested. The results show that chip function and performance indicators already meet the design requirements.