Patent ID: 6839253

Claim:
A multi-period cycle-alternate switching mode power supply control device, having a variable multi-period control cycle to effectively control certain power transfer elements of specific nature and assure such element and the loading at its rear end can operate more efficiently in a reliable range of specific nature, said device comprising: a power transfer control, having an input terminal, and said input terminal inputting an error signal, and using the error signal to adjust a duty width and obtain an adjusted signal at an output terminal; a dimming bias control, having one input terminal coupled to an output terminal of said power transfer control, and using a timing signal generated by said power transfer control as a reference source, while using another input of said dimming bias control to input an electric potential of an error signal and change the timing relation of the timing signal, and obtaining a set of control timing; a burst timing control, having an input terminal, and said input terminal having a dimming control input signal for comparing with a waveform signal generated by said burst timing control, and obtain a high/low control timing; and a steering logic control, sending an adjusted signal outputted from said power transfer control, a control timing outputted from said dimming bias control, and a timing outputted by said burst timing control in sequence to an ON/OFF signal at an output terminal of said burst timing control and being separated in different timing according to the sequence, and thus controlling an external component and then sending to a loading terminal after being processed trough said external component to control the action of the element at the loading terminal.