Abstract: The present invention relates to a speaker driver and an operation method thereof and includes an amp part configured to output a pulse voltage, in which an input signal is amplified on the basis of a supply voltage, to drive a capacitive speaker that generates sound by a driving voltage so that the driving voltage formed by filtering the pulse voltage is applied to the capacitive speaker, and a controller configured to adjust a magnitude of an input audio signal in a high frequency range and transmit the input audio signal to the amp part as the input signal to limit an overcurrent applied to the capacitive speaker by the driving voltage having a high frequency.

Abstract: The present invention relates to a speaker driver and an operation method thereof and includes an amp part configured to output a pulse voltage, in which an input signal is amplified on the basis of a supply voltage, to drive a capacitive speaker that generates sound by a driving voltage so that the driving voltage formed by filtering the pulse voltage is applied to the capacitive speaker, and a controller configured to adjust a magnitude of an input audio signal in a high frequency range and transmit the input audio signal to the amp part as the input signal to limit an overcurrent applied to the capacitive speaker by the driving voltage having a high frequency.

Abstract: A method for authenticating an electronic transaction includes: transmitting first authentication data to a first terminal and transmitting second authentication data to a second terminal; receiving first encryption data from the first terminal and receiving second encryption data from the second terminal, the first encryption data corresponding to the first authentication data and the second encryption data corresponding to the second authentication data; storing the first encryption data and the second encryption data; and authenticating the first terminal and the second terminal according to the first authentication data and the second authentication data. The first encryption data is encrypted by a first internal key of the first terminal, and the second encryption data is encrypted by a second internal key of the second terminal.

Abstract: A radio frequency (RF) filter is provided which includes a band pass filter unit and an amplifying unit. If a signal having a frequency in a first band is input, the RF filter performs band pass filtering, and if a signal having a frequency in a second band is input, the RF filter performs an amplifying process. The RF filter can be used for various RF signal processing devices, such as digital broadcast receiving tuners.

Abstract: An adjustable inductor includes a first conductor line to receive an alternating current (AC) signal, a second conductor line configured in a loop arrangement, to generate an inducting current upon receiving the AC signal at the first conductor line, and a switch to adjust an inductance of the first conductor line by switching a loop connection of the second conductor line according to an external control signal.

Abstract: An active balun for improving a phase matching characteristic includes a transistor part which has an input terminal receiving an input signal and first and second output terminals which output signals corresponding to the input signal, and a capacitance matching part provided on the side of one of the first and second output terminals which matches capacitances as seen from the first and second output terminals. The capacitance matching part may be composed of a transistor which bleeds a current from the one output terminal.

Abstract: A radio frequency (RF) filter is provided which includes a band pass filter unit and an amplifying unit. If a signal having a frequency in a first band is input, the RF filter performs band pass filtering, and if a signal having a frequency in a second band is input, the RF filter performs an amplifying process. The RF filter can be used for various RF signal processing devices, such as digital broadcast receiving tuners.

Abstract: A transmitter having a vertical BJT, capable of reducing power consumption, carrier leakage of a local oscillator and an error vector magnitude (EVM), is disclosed. In the transmitter, vertical BJTs implemented by a standard triplex well CMOS process are used in a frequency up-mixer and a baseband analog circuit including a DAC, an LPF, a VGA and a PGA, thereby improving the overall performance of the transmitter.

Abstract: A transmitter having a vertical BJT, capable of reducing power consumption, carrier leakage of a local oscillator and an error vector magnitude (EVM), is disclosed. In the transmitter, vertical BJTs implemented by a standard triplex well CMOS process are used in a frequency up-mixer and a baseband analog circuit including a DAC, an LPF, a VGA and a PGA, thereby improving the overall performance of the transmitter.

Abstract: The present invention is a method for controlling and emitting backlights of a mobile communications terminal in various operation mode according to a type of interrupts by allocating and coupling general purpose input output of a MODEM chip with each backlights of the mobile communications terminal and controlling each backlight individually. The method for controlling backlights of the0 mobile communications terminal, including steps of: a) detecting various interrupt generated by any operation of the mobile communications terminal; and b) controlling and emitting the backlights individually in a preset operation mode according to the interrupt detected at step a).

Abstract: The present invention is a method for controlling and emitting backlights of a mobile communications terminal in various operation mode according to a type of interrupts by allocating and coupling general purpose input output of a MODEM chip with each backlights of the mobile communications terminal and controlling each backlight individually. The method for controlling backlights of the0 mobile communications terminal, including steps of: a) detecting various interrupt generated by any operation of the mobile communications terminal; and b) controlling and emitting the backlights individually in a preset operation mode according to the interrupt detected at step a).