Analysis Of A Monolithic Buck DC-DC Converter Chip And Optimal Design Of Its Layout

Monolithic DC-DC converter chip has been widely used, because it has the characteristics of high level of integration, high cost-effective, the least peripheral devices and could form the high-efficiency power and so on.Firstly, research on and analysis the monolithic Buck DC-DC switching power supply chip for the working principle, system structure and PWM control mode; then module is divided according to functional needs and design requirements of the circuit, through the analysis and calculate each module to separate the high-pressure devives from the whole circuit; Moreover, specific analysis the integrated circuit modules including the current biased circuit, bandgap voltage circuit, error amplifier circuit, oscillator circuit, PWM comparator circuit, driver circuit, overheating protection circuit and over current protection. And based on cadence work platform using xiyue3um bipolar process model with spectre and Hspice EDA tools simulation them for system-level, and the simulation results verify the feasibility of the design and the correctness of the theory analysis; Divided the circuit elements of high and low voltage pipes in different regions when design layout, for high voltage parts using3um/40V design rules and low ones using3um/5V design rules. Through this optimal degign, the chip area and the cost are significantly reduced in the case of doesn’t affect the performance. The chip has been taped out after the DRC (Design Rule Check) and LVS (Layout Versus Schematics) verified, the chip performance test results indicate the correctness of the circuit and layout.