Research And Design Of A Constant Current And Voltage Controlled Power Supply Management Chip

With the rapid development of the technology in the electronic world, therequirements for higher function stability, efficiency and smaller volume have been putforward, which will lead to the replacement of conventional power supply. The Switchpower supply has been the guide of the future development of the modern power supply.According to the company project, the constant current and voltage controlled powersupply management chip with high precision has been designed, The chip is a highperformance offline PFM modulation controller and applied in low power adapter andAC/DC charger. The chip can operates in primary-side sensing and regulation.Consequently, opto coupler and TL431can be eliminated. Constant current and voltagemodes are respectively designed in the chip. In CC control, the largest output power andcurrent can be set with the current-limited resistor Rs of CS pin. In CV control, PFMoperations are utiliaed to achieve high performance and high efficiency. In addition, goodload regulation is achieved by the built-in cable drop compensation. The CC/CV controlledpower supply management chip circuit, includes overvoltage protection circuit, thebandgap reference circuit, soft-start circuit, leading edge blanking, over-current protection,under-voltage lockout circuit and so on. The the simulation and analysis of the variousindicators of the modules in the chip are conducted with Cadence software. Simulationresults indicate that relatively low operating current consumption and high operatingefficiency.Basis on LITE-ON40V1.0μmBiCMOS technology, the circuit layout design ofconstant current and voltage controlled power supply management chip is accomplished.DRC and LVS verification are accomplished. The resulst show that the function andperformance of the chip has met the design requirement. The loop dynamic response andstandby power dissipation are0.7ms and0.2W respectively.