Design Of A Green Mode PWM Swithcing Power Supply Control IC

With the rapid development of electronic technology, gradually a wide variety of electronic products are popular in every corner of life. Accompanied by the enhancement of environmental awareness, people set off the world gradually leading by the Europe Union energy revolution that a wide variety of electronic products are using power supply in the small size, light weight, high-energy conversion rate and small standby power with high performance but very low price.Based on the CMOS technology and the design EDA tool Cadence, the paper makes a full analysis of design on the basis of switching power supply technology principle. The article designs a high-performance, low power consumption PWM switching power supply chip. The chip abandoned a kind of error amplifier structure design of PWM control chip which is now used in current market. It uses a simple circuit structure of the output voltage detection and effective addition to eliminate the effect which caused by the error amplifier PWM control is not very high performance of chips, and to reduce the area of the chip and costs. In order to reduce the standby power, the chip designs a kind of green mode control circuit. When in the light-load or no load, the converters off-time can be increased through to reduce switching frequency. In order to better protect the external power MOSFET, the gate driver input voltage can be clamped by the chip. At the same time, the chip also has over-current protection, over-temperature protection, over-load protection, over-voltage protection and under-voltage protection. So when the chip in a abnormal state, the circuit cuts off immediately. The whole circuit and every sub-circuit are simulated by using the tools of H-spice. Finally, the simulation results show that the stability of integrated circuits and it can achieve all the indicators that the design requires.This paper designs the layout for the whole chip circuit, by using the Cadence tools Virtuoso and Dracula. Also, the paper makes a layout versus schematic (LVS) for the comparison between design and layout. In the end, the results and analysis are given after testing the chips which have been taped out.The temperature range of this power chip is -20℃～140℃. The chip can normally operate on the frequency of 65 kHz, and in green model it can work on the frequency of 22 kHz. The conversion efficiency is 75%. The chip can be used in battery chargers, power adaptor, set-top boxes power supply, open power supply, and other electronic equipment witha wide range of applications.