关键词: Boost开关变换器, 超宽电源电压范围, 恒定关断时间

Abstract: Aiming at the application scenarios of portable electronic devices and wearable devices, this article introduces a Boost converter that operates under a very wide power supply voltage range. The Boost converter uses a constant off-time (CFT, Constant off time) control mode, which avoids the slope compensation circuit required by the conventional fixed-frequency control method. The constant off-time is 400 ns. Micro-inductors and capacitors can be used for peripheral devices, which can greatly reduce the area occupied by the entire power module. The chip integrates 40 V LDMOS, the output voltage can reach up to 40 V, and the current limit is 100 mA. The Boost converter proposed in this paper is designed based on 0.35 μm BCD process. The simulation results show that the boost converter designed in this paper can work normally under the input voltage of 1 ~ 15 V.

Key words: Boost converter, ultra-wide supply, constant off-time