US 6,472,854 B2 · Battery operated power circuit and driving method thereof

Abstract

An FET 21 is connected in parallel to a series circuit of a switching device 13 and an inductor 12 between an input terminal 11a and an output terminal 11b, wherein an output voltage Vout is dropped only by an operation of the switching device 13; the FET 21 is turned on by a driving circuit 22 when the switching device 13 sustains an on duty factor of 100% so that a series resistance of the switching device 13 and the inductor 12 is connected in parallel to an on resistance of the FET 21, thereby increasing a supply current and extending a period during which an output voltage provided to the output terminal 11b is sustained at a predetermined level. Therefore, a power circuit capable of extending an operating time of a battery-operated power supply, a method for driving same, and further an electronic module implementing same can be obtained.

Claims17

Dependent claims

A power circuit, having a switching device and an inductor connected in series between an input terminal and an output terminal, for generating an output voltage on the output terminal by lowering an input voltage provided through the input terminal by a switching operation of the switching device and monitoring the output voltage to maintain the output voltage at a substantially constant level, the power circuit comprising:

a current control device for adjusting an amount of an electric current provided from the input terminal to the output terminal in response to a control signal , wherein the current control device is connected between the input terminal and the output terminal in parallel to the switching device and an inductor;
and
a driving means for generating the control signal for controlling the current control device to maintain the output voltage at the constant level.

An electronic component for use in a power circuit, comprising:

a package;
an input terminal provided on the package;
a first output terminal provided on the package;
a second output terminal provided on the package;
an inductor for performing the smoothing operation, wherein the inductor is connected between the first output terminal and the second output terminal;
a switching device for performing a switching operation, wherein the switching device is installed within the package and connected between the input terminal and the first output terminal;
a current control device for changing an amount of an electric current provided from the input terminal to the second output terminal based on a control signal, wherein the current control device is installed within the package and connected between the input terminal and the second output terminal;
and
a driving circuit for operating the current control device after the switching device is set to sustain an on duty factor of 100%, wherein the driving circuit is installed within the package and connected to a control terminal of the current control device, wherein the power circuit generates an output voltage on the second output terminal by lowering an input voltage provided through the input terminal by the switching operation of the switching device and monitoring the output voltage to maintain the output voltage at a substantially constant level.

6 more elements

Dependencies are inferred from the claim text.

Battery operated power circuit and driving method thereof

Life of this patent

Battery operated power circuit and driving method thereof

Life of this patent

Abstract

Claims17