Small signal modeling for the smart power IC

This paper presents a modeling method for the small-signal frequency response analysis of a monolithic power integrated circuit (IC). In this method, the switching duty cycle output of the power IC is converted into a discrete-time signal by a high-speed counter during every switching period, and the power IC´s control input signal is simultaneously sampled and converted into digital data using an analog-to-digital converter. Not only the transient response but also the frequency response of the power IC can be obtained. The smart power IC´s transfer function and dynamic model are finally synthesized from the measurement data. This modeling method, referred to as ldquosampling the transient and frequency responses of power ICs,rdquo can efficiently provide reliable and accurate models even if the switching frequency of a power IC is jittered or frequency modulated. The effectiveness and practicality of the methode were verified through experiments.