Average Inductor Current Sensor for Digitally Controlled Switched-Mode Power Supplies

作者：Rodriguez Miguel^*; Manuel Lopez Victor; Azcondo Francisco J; Sebastian Javier; Maksimovic Dragan

来源：IEEE Transactions on Power Electronics, 2012, 27(8): 3795-3806.

DOI：10.1109/TPEL.2012.2183893

• Analog-digital conversion
• current control
• digital control
• switched-mode power supplies

Current-mode control in digitally controlled switched-mode power supplies typically requires analog-to-digital (A/D) conversion of at least two signals, voltage, and current. The complexity of voltage A/D converters can be reduced using window A/D techniques. In conventional current A/D conversion, however, relatively high resolution is required over a wide range of signals, which results in increased complexity, power consumption, and cost of the controller. This paper proposes a very simple feedback sensor capable of high-resolution average inductor current sensing using two analog comparators and an analog low-pass filter. The approach requires very few external components and employs minimal digital hardware resources. A dynamic model and performance of the average inductor current sensor are experimentally verified on a 12-V input, 19-V output, 50-W boost converter prototype. The applicability of the proposed sensor is demonstrated in a digitally controlled 400-W, 400-V output Boost power factor preregulator.

• 出版日期2012-8