This paper presents a universal method for modeling the frequency response of comparators in switchmode controllers. As the main non-linearity in most switchmode controllers, understanding the comparator is the key to understanding the system. Based on discrete-time modeling, the proposed method is demonstrated to allow very precise predictions of comparator frequency response in a variety of control schemes. In the presented work, the modeling method is exemplified for the standard PWM and two different self-oscillating (a.k.a. sliding mode) control schemes. The proposed method is believed by the authors to be the first method that is able to handle these fundamentally different control schemes within a single modeling framework. Experimentally measured output impedance and comparator magnitude responses are compared to the model results. Great accuracy is achieved from DC to frequencies far beyond the switching frequency.
|Title of host publication||39th IEEE Annual Power Electronics Specialists Conference|
|Publication status||Published - 2008|
|Event||39th IEEE Annual Power Electronics Specialists Conference - Rhodes, Greece|
Duration: 15 Jun 2008 → 19 Jun 2008
Conference number: 39
|Conference||39th IEEE Annual Power Electronics Specialists Conference|
|Period||15/06/2008 → 19/06/2008|