Design Of Work In Dcm Mode Flyback Digital Converter XD1599

With the rapid development of the electronics industry, electronic equipment is becoming more and more necessary in people's life and work, which need the power supply for its normal operation. At first, power supply is used for simple electronic equipment, but with the increasing of electronic equipment, the function of electronic devices is becoming more and more complicated.This paper is based on the project “Small power Flyback AC/DC controller with constant current and constant voltage output”, which is from ultra-high-speed circuit design and electromagnetic compatibility ministry of education key laboratory of Xidian university.And according to the basic power supply topology and control theory of swithcing power supply, with high efficiency, high stability and practicality as the goal, combined with the specific application requirements of the chip, this paper has designed a high efficiency flyback AC/DC controller XD1403 with constant current and constant voltage output.This paper first introduces the concept of switching power supply, the digital switching power supply and the traditional analog digital power supply for a simple comparison between the advantages and disadvantages of the two, and a brief introduction of the digital power control technology. Then the topology of the switching power supply is introduced, and the working principle of the flyback converter is analyzed, and the main modules of the chip are designed.Finally, the simulation of the whole system is carried out.The XD1599 is a high performance AC/DC power supply controller which uses digital con trol technology to build peak current mode PWM flyback power supplies. The device toget her with an external active device(depletion mode NFET or NPN BJT) provides a fast star t-up meanwhile achieving ultra-low no-load power consumption. The device directly drive-s a power BJT and operates in quasi-resonant mode to provide high efficiency along with a number of key built-in protection features while minimizing the external component coun t, simplifying EMI design and lowering the total bill of material cost. The XD1599 remove the need for secondary feedback circuitry while achieving excellent line and load regulatin.It also eliminates the need for loop compensation components while maintaining stability over all operating conditions by using digital compensation technology.Pulse-by-pulse waveform analysis allows for a loop respons that is much faster than traditional solutions,resulting in improved dynamic load response, for both one-time and repetitive load transient. The built-in power limit function enables optimized transformer design in universal offline applications and allows for a wide input voltage range.Based on a process of 0.5?m CMOS model, XD1599 is designed with Cadence and simulated by AMS. The simulation results of whole system show that XD1599 can meet the standard requirements.