Abstract: Disclosed are a novel organic acid salt of amlodipine, its preparation method, and a pharmaceutical composition containing the same as a therapeutically active ingredient.

Abstract: Disclosed are a novel organic acid salt of amlodipine with superb physicochemical properties, its preparation method, and a pharmaceutical composition containing the same as a therapeutically active ingredient.

Abstract: An amplifier including an amplifier transistor that operates in an active region has main current flowing therethrough according to input voltage, and a linear transistor that is driven by offset positive-polarity input voltage to operate in a linear region and has auxiliary current flowing therethrough. The main current and auxiliary current are added to become output current. The offset positive-polarity voltage corresponds to the sum of AC component of the input voltage and an offset DC voltage. Here, a transistor stacked on the linear transistor is coupled to the amplifier transistor to secure the linear region operation of the linear transistor. The stacked transistor is driven by a voltage having polarity opposite to that of the input voltage.

Abstract: A novel crystalline organic acid salt of amlodipine having improved physiochemical properties, a preparation method thereof and a pharmaceutical composition comprising the same are provided.

Abstract: Disclosed are a novel organic acid salt of amlodipine, its preparation method, and a pharmaceutical composition containing as a therapeutically active ingredient the same.

Abstract: Disclosed are a novel organic acid salt of amlodipine with superb physicochemical properties, its preparation method, and a pharmaceutical composition containing the same as a therapeutically active ingredient.

Abstract: Disclosed are a novel organic acid salt of amlodipine, its preparation method, and a pharmaceutical composition containing the same as a therapeutically active ingredient.

Abstract: The present invention relates to a ROM division method for reducing the size of a ROM in a direct digital frequency synthesizer (DDFS), which is used to synthesize a frequency in a communication system requiring fast frequency conversion. A ROM consuming most energy in the system, a modified Nicholas architecture is brought forth to reduce the size of ROM. In this modified Nicholas architecture, a ROM is divided into coarse ROM and fine ROM to convert phase to sine value. The present invention divides the coarse ROM and the fine ROM into quantized ROM and error ROM respectively. Then, value stored in each ROM is segmented in certain intervals and the minimum quantized value in each of the section is stored in the quantized ROM, while the difference between the original ROM value and the quantized ROM value is stored in the error ROM. This way, the size of a ROM can be reduced. Phase value inputted in a DDFS, a sine value is calculated by adding the four ROM values, i.e.

Abstract: The present invention provides novel cathecol hydrazone derivatives of formula (I) or pharmaceutically acceptable salts thereof, wherein R1 is C1-7 alkyl or C3-7 cycloalkyl; R2 is hydrogen, hydroxy, C1-5 alkyl or —CH2CH2C(═O)NH2; R3 and R4 are independently hydrogen, C1-7 alkyl, —C(═X)—R5, or 2-, 3- or 4-pyridyl, prymidyl or phenyl substituted with one or two selected from a group consisting of halogen, C1-6 alkoxy, nitro, trifluoromethyl, C1-6 alkyl and carboxyl, or R3 and R4 are directly bonded by C3-4 containing oxygen, sulfur or nitrogen to form a heterocyclic ring, X is oxygen, sulfur or NH and R5 is C1-7 alkyl, —NHR6, CONH2 or 2-, 3- or 4-pyridyl, prymidyl or phenyl substituted with one selected from a group consisting of halogen, C1-6 alkoxy, nitrile, trifluoromethyl, C1-6 alkyl and carboxyl, and R6 is hydrogen, hydroxy, NH2, C1-5 alkoxy, C1-5 alkyl, pyridyl or phenyl.

Abstract: An automatically gain controllable linear differential amplifier using a variable degeneration resistor is disclosed. The linear differential amplifier includes an input end, a bias current source, a load unit, a first MOS transistor and a second MOS transistor. The linear differential amplifiers of the present invention can control an amplifying gain according to an input signal and improve linearity IIP3 without needing additional power consumption caused by improving the linearity. The automatically gain controllable linear differential amplifier uses NMOS/PMOS transistor so an integration process of the amplifier can be implemented more conveniently and efficiently.

Abstract: A variable gain amplifier (VGA) circuitry for implementing gain as a pseudo exponential function by using the linear area of metal oxide semiconductor field effect transistors (MOSFETs) is provided. The VGA circuitry includes a fixed resistor and a variable resistor, which is connected in serial to the fixed resistor and implemented by combining one or more MOSFETs operating in a linear area with different control voltages to each MOSFET. Although the MOSFET has no exponential characteristics, the VGA circuitry can easily implement a pseudo exponential function with a simple structure. Further, since a complex circuit for generating an exponential function is not necessary, power consumption thereof can be eliminated.

Abstract: An automatically gain controllable linear differential amplifier using a variable degeneration resistor is disclosed. The linear differential amplifier includes an input end, a bias current source, a load unit, a first MOS transistor and a second MOS transistor. The linear differential amplifiers of the present invention can control an amplifying gain according to an input signal and improve linearity IIP3 without needing additional power consumption caused by improving the linearity The automatically gain controllable linear differential amplifier uses NMOS/PMOS transistor so an integration process of the amplifier can be implemented more conveniently and efficiently.

Abstract: The present invention relates to an integrated filter circuit for digitally controlling characteristics of inductor and capacitor to thereby produce a controlled resonant frequency. The integrated circuit includes a number of inductors being connected in series between a high frequency input node and a high frequency output node, a plurality of capacitors each connected to a connection node of said each inductors, a plurality of switches, each connected between each capacitor and a ground and a feedback control unit for controlling the switches by sensing an output signal from the high frequency output node to thereby selectively couple each capacitor to the ground through a selected switches based on the sensed output signal.

Abstract: The present invention relates to a frequency mixer utilized in a transceiver of radio frequency band. The frequency mixer for a radio frequency transceiver, includes two NMOS transistors, which are commonly connected, for generating a mixed signal combined with even harmonics, wherein a first end of the NMOS transistors is input a radio frequency signal, a second end of the NMOS transistors outputs the mixed signal, and gates of the NMOS transistors receive differential signals of local oscillator. The frequency mixer needs only half local oscillation frequency and a fundamental frequency of local oscillator is not presented. Therefore, the present invention can prevent generation of DC Voltage offset and also reduce frequency of local oscillator by half when it is utilized in a heterodyne transceiver.

Abstract: The present invention relates to a ROM division method for reducing the size of a ROM in a direct digital frequency synthesizer (DDFS), which is used to synthesize a frequency in a communication system requiring fast frequency conversion. A ROM consuming most energy in the system, a modified Nicholas architecture is brought forth to reduce the size of ROM. In this modified Nicholas architecture, a ROM is divided into coarse ROM and fine ROM to convert phase to sine value. The present invention divides the coarse ROM and the fine ROM into quantized ROM and error ROM respectively. Then, value stored in each ROM is segmented in certain intervals and the minimum quantized value in each of the section is stored in the quantized ROM, while the difference between the original ROM value and the quantized ROM value is stored in the error ROM. This way, the size of a ROM can be reduced. Phase value inputted in a DDFS, a sine value is calculated by adding the four ROM values, i.e.

Abstract: Pyridone carboxylic acid compounds and pharmaceutically acceptable salts and physiologically hydrolyzable esters thereof are provided which are represented by the formula: ##STR1## wherein R.sub.1 is a lower alkyl, a halogen-substituted lower alkyl, a lower alkenyl, a cycloalkyl, or a substituted- or unsubstituted-phenyl group; R.sub.2 is a hydrogen atom, or a lower alkyl or an amino group; A is a nitrogen atom or the group C--X wherein X is a hydrogen or a halogen atom, or an alkoxy group; and Z is a group having the formula: ##STR2## wherein n is 1 or 2; R.sub.3 and R.sub.4 each represent a hydrogen atom or a lower alkyl group, with proviso that, if n is 2, one of R.sub.3 and R.sub.4 is a hydrogen atom; R.sub.5 and R.sub.6 each represent a hydrogen atom, or a hydroxy, a lower alkoxy or an amino group which is unsubstituted or substituted by a lower alkyl group, with proviso that one of R.sub.5 and R.sub.6 is a hydrogen atom; and R.sub.7 is a hydrogen atom or a lower alkyl group.