Design Technology About AC/DC Controller Controlled By Primary Side Feedback Signal To Supply Constant Output

The paper is based on the project in Xi’an Innuovo Microelectronics co., LTD,which is AC/DC IC controller chip design. It is controlled by the primary sidefeedback signal and it can supply the constant output. The paper makes it studythoroughly.With the current development and future development trends of switching modepower supply, we design the chip. First, studying some theoretical knowledge, we indepth understand the switching power supply system how to work, modulate, controland work. According to energy saving, high efficiency, overall performance indicators,we design the chip block diagram. Then, we design, simulate and design each moduleto optimization. Finally, we do systematic simulation, knowing the chip performanceindicators meet the requirements. The chip is suit to low-power AC/DC power adapterand battery charger. What’s more, it has high integration and high-performance. Thesystem applications eliminate the need for TL431and optocoupler, reducing costs.When output loads work in heavy-duty, the chip can work in the CC mode by PFM,and in light-duty it can work in the CV mode by PWM. The chip provides a soft startfunction and a variety of fully restore protection modes, including: by-cycle currentlimit protection (OCP), VCC over-voltage, clamping voltage and low voltage shutdown (UVLO). In order to better protect the high-voltage power MOSFET, the gatedrive output voltage is clamped at16V. Because the chip in the totem pole gate driveoutput uses a frequency jitter, switching mode power supply can improve EMIperformance. The chip can be used as the best alternative of linear power supply orRCC-mode power supply to improve the overall performance and effectively reducethe system cost.The chip is based on the1us40V BiCMOS process library to complete thedesign, simulation and verification. The test results show that the performanceindicators have been designed to meet the requirements.