C. H. Kao P. Y. Tsai W. P. Lin M. C. Chou A Self-oscillating Switching Power amplifier. 67-79 2009 18 Journal of Circuits, Systems, and Computers 1 http://dx.doi.org/10.1142/S0218126609004934 db/journals/jcsc/jcsc18.html#KaoTLC09