Abstract: The present invention relates voltage conversion device in which a regulated output voltage is supplied by current pulses generated by the voltage conversion device from a voltage source. In particular, the invention relates to an improved control of an pulse frequency modulation (PFM) operation mode in which the frequency of the generated current pulses is modulated to regulated the desired output voltage, namely how PFM pulses can be generated without the need for a high-frequency clock of a time controlled system. By having pulse phases are current mode controlled and providing a mode detector to generate the right kind of current pulse, the high-frequency clock is no longer needed. Further, the presented solution allows for a higher PWM as well as PFM frequency, the external components of the converter can be made smaller. Eliminating the need for a high-frequency clock makes the device simpler, smaller and more energy-efficient.

Abstract: A fully digital DC/DC automatic up/down converter circuit converts an input voltage to an output voltage of a predetermined value based on a switching operation. The switching operation includes switching operation comprise-cycles having at least one switching operation phase. The converter is controlled by a digital controller having a look-up table in which a plurality of data is stored. The digital controller uses certain data from the plurality of data with respect to an actual switched operating mode for continuously adjusting the begin and the end of a switching operation. The switched operating modes are a PWM and a PFM mode.

Abstract: The present invention relates voltage conversion device in which a regulated output voltage is supplied by current pulses generated by the voltage conversion device from a voltage source. In particular, the invention relates to an improved control of an pulse frequency modulation (PFM) operation mode in which the frequency of the generated current pulses is modulated to regulated the desired output voltage, namely how PFM pulses can be generated without the need for a high-frequency clock of a time controlled system. By having pulse phases are current mode controlled and providing a mode detector to generate the right kind of current pulse, the high-frequency clock is no longer needed. Further, the presented solution allows for a higher PWM as well as PFM frequency, the external components of the converter can be made smaller. Eliminating the need for a high-frequency clock makes the device simpler, smaller and more energy-efficient.

Abstract: The present invention relates to a fully digital DC/DC automatic up/down converter circuit (10) for converting an input voltage to an output voltage of a predetermined value based on a switching operation. The switching operation comprises switching operation cycles, which comprise at least one switching operation phase. The converter is controlled by digital controller (20), which comprises a look-up table in which a plurality of data is stored. The digital controller uses certain data from said plurality of data with respect to an actual switched operating mode for continuous adjusting begin and end of a switching operation. The switched operating modes are a PWM and a PFM mode. The converter is optimal for portable electronic equipment, which come with a battery pack for power supply. Advantageously, the converter of the invention provides a stable output voltage over the whole range of the input voltage supplied by such battery pack.