摘要
设计了一款内置功率MOSFET的电流模式降压型DC—DC转换器。该DC／DC转换器采用PWM控制，在传统的PWM结构上加入电流反馈环路，改善了传统电压模式DC／DC的缺点，能够取代国际上流行的三端可调线性稳压器。该转换器具有瞬态响应快，启动过冲小，输出纹波小，输出电压可调等特点。正常工作情况，输入电压5～25V，输出电流2A，工作频率400KHz。采用0．8μm BiCMOS工艺模型进行了Spectre模拟，并且制作了该芯片。经过验证，各项指标符合设计要求。
A buck DC -DC converter with power MOSFET inside is analyzed and designed. It is controlled by Pulse -Width -Modulation （PWM）. The circuit has a current-mode feedback loop compared to the conventional structure, thus it wipes out the disadvantages of voltage - mode DC/DC converter. Fast transient response speed, tiny overcharge voltage, programmable output voltage and small ripple voltage are the characteristics of the circuit. In a typical use, the input voltage is 5 - 25V, output voltage is 5V, output current is 2A, the operation frequency is 400 KHz. At the end, the design, based on the 0.8 μm BiCMOS model with Spectre, is verified.
出处
《微处理机》
2006年第3期7-10,共4页
Microprocessors
