Research And Design Of A Monolithic BUCK Type DC/DC Control IC Based On The Sample Of Metal Resistance

Now in the world, miniaturized, intelligent and high-efficiency of the switching power supply is increasingly becoming an ideal portable electronic products. With increasing wide range of applications, its position is in the growing importance of electronic products. The researchers for the pursuit of high-performance switching power supply, especially for high frequency, high efficiency are never stopped. Recently, digital switching power supply has become a new research direction, and researchers have made many breakthroughs. In highly sophisticated analog switching power supply, Buck-type DC / DC converter is the most widely used, this is due to its relatively simple circuit structure design which can meet most of our electronic products requirements for power supply, inability to the function, the volume as well as the conversion efficiency with high cost performance characteristics.It is a fixed frequency of 500 KHz, BUCK-type DC / DC switching converter in this paper, which has a high input range, low output voltage ripple, the load current is large and many other advantages. By using the output of the bias circuit and the use of a booster circuit design, the power switch is working in the deep saturation region while it is turned on. On-resistance can be reduced to 0.07 ?, the output current can maintain high efficiency over a wide range. On the chip integrates a maximum output of 4.5A power switch and the desired oscillator, control and logic circuitry. The high switching frequency allows appropriate to reduce the size of external components, the use of peak current control mode, which has a good transient response and loop stability. Sampling resistor metal is alloy resistance. The use of nickel-chromium or similar technology as alloy vacuum plating, after the film on the surface of white porcelain rods and cutting debugging resistance,it is with high precision resistance, impact strength and thermal stability current characteristicsFirstly, a concise description of switching power supply from the origin, development status and future direction in the first chapter, etc. Then in the next chapter, elaborate switching power supply from the principle of common topology and control mode, in order for the next DC/ DC converter overall concept and design for bedding. Drawing on plenty of theoretical knowledge relevant the paper design, the main circuit of the inverter modules were designed and make simulation examples, and contrast to the principles of the circuit described in some important circuit module design, such as the bandgap reference circuit module.In the actual design, we use the segmented current slope compensation circuit, compared to the traditional single-slope compensation, it can adapt to a more liberal inductor values and the output input voltage ratio, with better transient response and loop stability. Finally, for functional simulation, conversion efficiency can reach more than 86% when the load current is light, compared to traditional design it improves more than 10%. This is because the use of a special circuit design, at higher voltage input, make the most of the internal circuitry to draw current from the output port instead draw from the input power supply terminal. Other indicators are to meet the design requirements.