Power circuit and method for controlling same circuit

Abstract

A power circuit is provided which has a small peak value of a current from a power source even in the case of a load in which a load current repeats periodically and alternately a burst flow in a burst period and a non-burst flow in a non-burst period. The above power circuit is provided with a power source section, a power controlling section, and an energy storing section having a storage capacitor being connected to an output terminal, a current controlling circuit to control values of detecting resistors according to a result of detection of a voltage input from a power source section and a control switching device having a field effect transistor switch being connected between input and output terminals and a circuit made up of a capacitor in which a flowing period of an output current is controlled by exerting the field effect transistor switch according to a control signal being produced by detecting a change in an input power voltage using a voltage occurring at another terminal of the detecting resistor.

Description

technical field [0001] The present invention relates to a power supply circuit capable of generating a peak power supply current suitable for supplying loads with cyclically varying power consumption and capable of allowing the amount of current consumed to exceed the upper limit for a set period of time and a method of controlling the power supply circuit. limit. [0002] This application claims priority from Japanese Patent Application No. 2002-045219 filed on February 21, 2002, which is incorporated herein by reference. Background technique [0003] In recent years, as terminals of portable devices have become multifunctional to connect to or access the Internet, distribute moving pictures, and the like, transmission speeds and data communication volumes tend to increase. Moreover, in essence, the terminals of these portable devices are not only made multifunctional, but also made smaller and lighter from the viewpoint of ease of use. [0004] On the other hand, as term...

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Problems solved by technology

[0007] However, in the case of such portable devices whose load varies with time, such devices specifically refer to digital devices popular in recent years as devices operating according to the TDMA (Time Division Multiple Access) method, such as digital data transmission systems, because their batteries The voltage varies with time, and matching between the minimum driving voltage and the end-of-discharge voltage becomes difficult, so the problem with conventional power supply circuits is that they cannot operate the battery fully efficiently

[0008] Also, in the case of a device powered by power from a personal computer serving as a host according to USB (Universal Serial Bus) which is an Internet specification, since there is an upper limit to the current used in USB, a device that consumes more current than the upper limit cannot be used. current device

[0009] Therefore, the problem of the conventional power supply circuit is that it is impossible to effectively use the battery serving as the power supply, and the current exceeding the limit value cannot be used

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