The commonly used average model is not applicable to predict the stability performances of constant on -time (COT) controlled buck converters. It has been reported that the issues of stability can be addressed by using the control signal to output voltage transfer function of the converters, named G _VC , for such class of converters. G _VC can be mathematically derived using describing-function approach to include the effects of side-band harmonics of the pulsewidth modulation (PWM) modulator. This is essential for modeling the control behavior of the COT converter class. However, the actual G _VC can deviate significantly from the derived ideal model. Therefore, a measured G _VC transfer function is important for real-world stability predictions. G _VC measurement, however, is often not feasible because the points of measurements are physically inaccessible due to integrated control circuit implementation. In this article, a realistic G _VC extraction method is proposed for each of the four commonly used COT schemes. Based on the measured G _VC , a procedure to predict the stability boundary is proposed and verified.

中文翻译：

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基于集成电路的恒定导通时间控制降压转换器的稳定性预测

常用的平均模型不适用于预测常数的稳定性能 上 时（COT）控制的降压转换器。据报道，可以通过使用控制信号输出转换器的电压传递函数来解决稳定性问题，该转换器名为G _VC ，用于此类转换器。G _VC可以使用描述函数方法来数学推导，以包括脉宽调制（PWM）调制器的边带谐波的影响。这对于建模COT转换器类的控制行为至关重要。但是，实际G _VC可能会大大偏离导出的理想模型。因此，G _VC传递函数对于真实世界的稳定性预测很重要。G 然而，由于集成控制电路的实现，_VC测量通常不可行，因为在物理上无法访问测量点。在本文中，一个现实的G 针对四种常用的COT方案中的每一种，提出了_VC提取方法。根据实测G _VC ，预测稳定边界的过程，提出并验证。