Abstract: A battery load detecting device includes: a battery check pulse generator generating a check pulse in response to a check enable signal; a constant voltage regulator generating a battery status signal in response to a first battery check signal; and a battery detection determining unit comparing a predetermined reference signal with the battery status signal to generate a comparison result signal, using the comparison result signal and the check pulse to generate a second battery check signal, and using the second battery check signal to generate a battery detection signal indicating whether a chargeable battery is electrically connected to the constant voltage regulator.

Abstract: A portable apparatus includes a system configured to receive a system current and perform a function, a charging battery configured to be charged with a charging battery current and supply power to the system, and a power management circuit configured to receive an externally supplied power, supply the system current to the system, and supply the charging battery current to the charging battery based on a sensed level of the system current, wherein the charging battery current decreases in proportion to the system current.

Abstract: A charging circuit includes a current mirror block configured to charge a load in response to a control voltage applied thereto, and a charge controller configured to generate the control voltage in response to comparison result values obtained by comparing a current sensing value and a voltage sensing value of the current mirror block with respective reference values. The comparison result value are applied to the gates of MOS transistors connected in series. The charge controller is configured to switch a charge mode from a constant current charge mode to a constant voltage charge mode when the charge state of the load reaches a predetermined state.

Abstract: A programmable variable gain amplifier includes at least three amplifiers. A first amplifier is configured to amplify an input signal. A second amplifier, which includes a programmable output load stage, is configured to receive an output signal from the first amplifier and to output a first differential output signal. The output load stage includes multiple first switches and multiple first diode-connected transistors that are open-circuited or short-circuited by the first switches. A third amplifier, which includes a programmable current mirror input stage, is configured to receive the first differential output signal from the second amplifier through the current mirror input stage and to output a second differential output signal. The current mirror input stage includes multiple second switches and multiple second transistors that are open-circuited or short-circuited by the plurality of second switches.

Abstract: A portable apparatus includes a system configured to receive a system current and perform a function, a charging battery configured to be charged with a charging battery current and supply power to the system, and a power management circuit configured to receive an externally supplied power, supply the system current to the system, and supply the charging battery current to the charging battery based on a sensed level of the system current, wherein the charging battery current decreases in proportion to the system current.

Abstract: A battery load detecting device includes: a battery check pulse generator generating a check pulse in response to a check enable signal; a constant voltage regulator generating a battery status signal in response to a first battery check signal; and a battery detection determining unit comparing a predetermined reference signal with the battery status signal to generate a comparison result signal, using the comparison result signal and the check pulse to generate a second battery check signal, and using the second battery check signal to generate a battery detection signal indicating whether a chargeable battery is electrically connected to the constant voltage regulator.

Abstract: A charging circuit includes a current mirror block configured to charge a load in response to a control voltage applied thereto, and a charge controller configured to generate the control voltage in response to comparison result values obtained by comparing a current sensing value and a voltage sensing value of the current mirror block with respective reference values. The comparison result value are applied to the gates of MOS transistors connected in series. The charge controller is configured to switch a charge mode from a constant current charge mode to a constant voltage charge mode when the charge state of the load reaches a predetermined state.

Abstract: A transconductor for substantially canceling or reducing a direct current (DC) output offset and a method thereof are provided. The transconductor includes a differential amplifier, a sensing circuit, and a feedback current generation circuit. The differential amplifier outputs output signals having a DC output offset therebetween due to a difference between input signals or a mismatch between input terminals. The sensing circuit senses the DC output offset and outputs a sensing signal. The feedback current generation circuit provides a feedback current for adjusting a level of the output signals to the input stage of the differential amplifier in response to the sensing signal. Accordingly, the transconductor substantially cancels or reduces the DC output offset between the output signals in response to the feedback current.

Abstract: A programmable variable gain amplifier includes at least three amplifiers. A first amplifier is configured to amplify an input signal. A second amplifier, which includes a programmable output load stage, is configured to receive an output signal from the first amplifier and to output a first differential output signal. The output load stage includes multiple first switches and multiple first diode-connected transistors that are open-circuited or short-circuited by the first switches. A third amplifier, which includes a programmable current mirror input stage, is configured to receive the first differential output signal from the second amplifier through the current mirror input stage and to output a second differential output signal. The current mirror input stage includes multiple second switches and multiple second transistors that are open-circuited or short-circuited by the plurality of second switches.

Abstract: A transconductor for substantially canceling or reducing a direct current (DC) output offset and a method thereof are provided. The transconductor includes a differential amplifier, a sensing circuit, and a feedback current generation circuit. The differential amplifier outputs output signals having a DC output offset therebetween due to a difference between input signals or a mismatch between input terminals. The sensing circuit senses the DC output offset and outputs a sensing signal. The feedback current generation circuit provides a feedback current for adjusting a level of the output signals to the input stage of the differential amplifier in response to the sensing signal. Accordingly, the transconductor substantially cancels or reduces the DC output offset between the output signals in response to the feedback current.