中文摘要：

针对降低多模式开关电源控制芯片在轻载与待机工作模式下功耗，提高其全负载条件下工作效率的需要，提出一种开关电源控制芯片供电系统的设计方案，实现了其在启动、关断、重载、轻载以及待机等各种工作情况下的高效率低功耗工作。该供电系统主要包括欠压锁定电路、数字模块电源单元和两种不同的模拟模块电源单元，以及状态检测模块和模式控制逻辑单元，能够实现电源的上电、掉电控制，同时能够根据电源的负载条件控制各模块的开通关断以实现低功耗工作。该系统已应用于绿色多模式反激式开关控制器的设计中，取得了提高电源效率、降低待机功耗的作用。芯片采用1．5μm BiCMOS工艺设计制成。测试表明，所设计电源的各项指标均已达到设计要求。

英文摘要：

To reduce the power consumption of multi-mode switching power supply controller chip in light load and standby conditions and enhance its efficiency over the entire load range, a novel supply system was proposed in this paper. Supplied by it, the chip could realize high efficiency, low power operation in different conditions including start-up, shut-down, heavy load, light load and standby. The system consists of a under voltage lockout （UVLO） module, a power source for digital modules, two voltage regulators for analogue modules, a voltage detection module and a control logic module. By controlling switching on/off some inner blocks according to the load conditions, the chip could keep low power operation. This power system was successfully applied to a multi-mode controller for flyback converter featuring high efficiency and low power consumption at standby. It was designed and fabricated in 1.5 μm BiCMOS technology. Test results showed that all expected performances were successfully achieved.