High Frequency Buck Converter Design Using Time-Based Control Techniques
High Frequency Buck Converter Design Using Time-Based Control Techniques
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DOI：
10.1109/jssc.2014.2378216
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发表时间：
2015-04
影响因子：
5.4
通讯作者：
S. Kim;Q. Khan;Mrunmay Talegaonkar;A. Elshazly;A. Rao;Nathanael Griesert;Greg Winter;W. McIntyre;P. Hanumolu
中科院分区：
文献类型：
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作者：
S. Kim;Q. Khan;Mrunmay Talegaonkar;A. Elshazly;A. Rao;Nathanael Griesert;Greg Winter;W. McIntyre;P. Hanumolu
提出了一种用于高开关频率降压变换器设计的时基控制技术。使用时间作为处理变量，所提出的控制器与CMOS电平的数字类信号，但不添加任何量化误差。环形振荡器被用作积分器，代替传统的opamp-RC或G-M-C积分器，而延迟线被用于执行电压到时间的转换和求和时间信号。一个简单的触发器从控制器的时基输出产生脉宽调制信号。因此，基于时间的控制消除了对宽带误差放大器、模拟控制器中的脉宽调制器（PWM）或数字控制器中的高分辨率模数转换器（ADC）和数字PWM的需要。因此，它可以实现在小面积和最小的功率。在180 nm CMOS工艺制造，原型降压转换器占用0.24平方毫米的有效面积，其中控制器仅占0.0375平方毫米。该器件工作在宽开关频率范围（10-25 MHz）内，可在1.8 V输入电压下将输出调节至0.6 V至1.5 V范围内的任何所需电压。负载电流阶跃为500 mA时，建立时间小于3.5 μs，基准跟踪带宽约为1 MHz。峰值效率超过94%，静态电流仅为2 μA/MHz。
Time-based control techniques for the design of high switching frequency buck converters are presented. Using time as the processing variable, the proposed controller operates with CMOS-level digital-like signals but without adding any quantization error. A ring oscillator is used as an integrator in place of conventional opamp-RC or G m-C integrators while a delay line is used to perform voltage to time conversion and to sum time signals. A simple flip-flop generates pulse-width modulated signal from the time-based output of the controller. Hence time-based control eliminates the need for wide bandwidth error amplifier, pulse-width modulator (PWM) in analog controllers or high resolution analog-to-digital converter (ADC) and digital PWM in digital controllers. As a result, it can be implemented in small area and with minimal power. Fabricated in a 180 nm CMOS process, the prototype buck converter occupies an active area of 0.24 mm2, of which the controller occupies only 0.0375 mm2. It operates over a wide range of switching frequencies (10-25 MHz) and regulates output to any desired voltage in the range of 0.6 V to 1.5 V with 1.8 V input voltage. With a 500 mA step in the load current, the settling time is less than 3.5 μs and the measured reference tracking bandwidth is about 1 MHz. Better than 94% peak efficiency is achieved while consuming a quiescent current of only 2 μA/MHz.