Orise Technology Co., Ltd.

Ming-Chien Li

Yen-Lin Huang

Lin-Chien Chen

Kuei-Kai Chang

A DC-DC converter with auto-switching between pulse width modulation (PWM) and pulse frequency modulation (PFM) is used in an organic light emitting diode (OLED) display and judges power consumption of an OLED array of the display according to display data of the display and thus determines a switching time between PWM and PFM. The converter comprises a content statistic unit, an auto-switching control unit, a PWM controller, a PFM controller and a power generator. The content statistic unit receives and accumulates the display data of the OLED display and then outputs a statistic value. The auto-switching control unit outputs a control signal according to the statistic value to control the PWM controller and the PFM controller and to switch to a PWM mode or a PFM mode.

DC-DC converter with auto-switching between PWM and PFM and OLED display using the same

A method for stabling a voltage, a pulse frequency modulating circuit and a power supply using the same are provided. The method includes the following steps. First, a comparing signal is provided. Then, set the comparing signal to be a first logic state when the voltage to be stabilized is lower than a preset voltage. Next provide a pulse signal when the comparing signal is set in the first logic state. Afterwards, adjust the enable time of the pulse signal based on the number of times of logic state changing of the comparing signal within a preset period and, adjust the voltage according to the enable time of the pulse signal.

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Yunlin County, Taiwan

Ming-Chien Li