Design Of AC-DC PWM Switching Power Supply Control IC

Along with the rapid development of electronic information industry, the demand of the switching power supply increases rapidly.The core of switching power supply control circuit to achieve integrated is the development direction of switching power supply. The pulse-width modulation mode switching power supply has advantages, such as good frequency characteristic, high linearity, smalle output voltage ripple, and others. Switch mode power supplies integrated PWM control chip are widely used in the communications, computer, and other fields.Based on the Bipolar technology, using Cadence EDA design tools, in the study of principle of switching power supply, this paper designs a kind of AC-DC PWM switching power supply controller chip. The paper analyzed detailedly the working principle and the classification of the switching power supply controller chip. According to functional needs, the paper designs the whole circuit of switching power supply controller chip and refines its internal various functional modules. The main modules of PWM controller chip include voltage references, oscillator, the protection circuits, slope compensation circuits, and other functional modules. In this paper, the design of switching power supply controller chip uses a simple circuit structure detect the output voltage, effectively getting rid of impact of performance on the PWM controller chip because of the error amplifier's low accuracy, reducing the area and cost of the chip.The whole circuits of chip are designed using the CSWC 1.8μm Bipolar process library. The circuits which are simulated and verified by Cadence Spectre reach the set targets. Finally, according to circuit design draw the layout and complete the design through DRC and LVS verification.In this paper, the design AC-DC PWM switching power supply controller chip, the working temperature range from 0℃-130℃, the working frequency is 60KHz, the maximum time proportion of its high level is 78 percent.