Abstract:
PURPOSE: A transconductance amplifier having high linearity and high gain is provided to maintain the linearity without increasing the current by forming an input terminal with NMOS transistors and PMOS transistors. CONSTITUTION: A transconductance amplifier having high linearity and high gain includes the first and the second input terminals and the first and the second output terminals. Input signals are inputted into a plurality of NMOS transistors(mn1-mn6) and a plurality of PMOS transistors(mp1-mp6) of the first and the second input terminals. The input signals received from the first and the second input terminals are amplified as much as the gain proportional to the conductance of the NMOS transistors(mn1-mn6) and the PMOS transistors(mp1-mp6). The amplified input signals are outputted to the first and the second output terminals.
Abstract:
PURPOSE: A variable gain amplification circuit of an automatic gain control is provided, which achieves a pseudo exponential function with a simple configuration, and prevents power consumption. CONSTITUTION: A fixed resistor part(R) receives an electric signal, and a variable resistor part(r) is connected to the fixed resistor part serially and has a plurality of NMOS transistors connected in parallel each other by applying different control voltage. The fixed resistor part has the plurality of NMOS transistors operating in a saturated area. The variable resistor part acts as one variable resistor by connecting the plurality of NMOS transistors in parallel operating in a linear area.
Abstract:
PURPOSE: A gain control device capable of dB-linear gain control at an analog circuit and an amplifier according to that are provided to independently control the dB-linear gain by controlling gain as dB-linearly according to linear change of resistance value of variable resistance. CONSTITUTION: A gain control unit(400) is comprised of a first input resistive unit(410) and a second input resistive unit(420). The first input resistive unit is comprised of a first variable register and the linearly changeable first fix resistance. The first variable register is connected between the input signal and virtual ground node of amount. The first fix resistance is connected to the input signal and virtual ground node of the negative principle in nature. The second input resistive unit is comprised of the second variable resistance and the linearly changeable second fixed resistance. The second variable resistance is connected between the input signal and virtual ground node of said the negative principle in nature. The second fixed resistance is connected to the input signal and virtual ground node of amount.
Abstract:
Provided are a dynamic element-matching method, a multi-bit Digital-to-Analog Converter (DAC), and a delta-sigma modulator with the multi-bit DAC and delta-sigma DAC with the multi-bit DAC. The dynamic element-matching method relates to preventing periodic signal components (in-band tones) from being generated from a delta-sigma modulator of a delta-sigma Analog-to-Digital Converter (ADC) and a multi-bit DAC used in a delta-sigma DAC. Unit elements are selected in a new sequence according to a simple algorithm every time that each of unit elements is selected once, and thus the unit elements are not periodically used. Consequently, it is possible to prevent in-band tones caused by a conventional Data Weighted Averaging (DWA) algorithm.
Abstract:
본 발명의 목적은 두 개의 피드백 루프를 적용한 회로를 구현하여, 낮은 전압에서도 동작이 가능한 구조를 가지며, 전원 노이즈를 억제하기 위하여 높은 PSRR(Power Supply Rejection Ratio) 특성을 가지도록 하였으며, 더불어 기존의 일반적인 기준 전압 발생기에서 나타나는 전압-전류 변환기가 필요하지 않은 구조를 갖는 낮은 기준 전류발생기를 제공하는 것이다. 본 발명은 소정의 전류를 전달받아 제 1 전압을 발생하되 상기 제 1 전압은 온도에 대응하여 전압레벨이 감소하는 제 1 전압발생부, 제 2 전압을 발생하되 상기 제 2 전압은 온도에 대응하여 전압레벨이 높아지는 제 2 전압발생부, 상기 제 1 전압에 대응한 제 1 전류를 발생하는 제 1 전류 발생부, 상기 제 2 전압에 대응한 제 2 전류를 발생하는 제 2 전류 발생부 및 상기 제 1 및 제 2 전류를 전달받아 상기 제 1 및 제 2 전류가 합산된 기준전류를 생성하는 기준전류 발생부를 포함하는 기준전류 발생기를 제공하는 것이다.
Abstract:
본 발명은 전류셀 구동 방식의 디지털-아날로그 변환기에서 전류셀 소자간 부정합에 무관하게 1 비트의 해상도를 확장시킨 전류셀 구동 방식의 디지털-아날로그 변환기에 관한 것이다. 본 발명에 따른 전류셀 구동 방식의 디지털-아날로그 변환기는, N비트의 디지털 입력신호(D IN )를 수신하여 2개의 N-1 비트 디지털 신호(D IN1 , D IN2 )로 변환하는 디코더; 상기 디지털 신호(D IN1 , D IN2 )에 기초한 전류량을 제공하는 M(= 2 N-1 )개의 전류셀; 상기 2개의 N-1 비트의 디지털 입력신호(D IN1 , D IN2 )에 기초한 전류량에 대응하는 제1 및 제2 아날로그 전압을 제1 및 제2 클럭신호(Q 1 , Q 2 )에 따라 각각 출력하는 전류셀 구동부; 및 상기 제1 및 제2 클럭신호를 기준으로 상기 제1 및 제2 아날로그 전압을 샘플링 및 홀딩하여 글리치가 제거된 신호를 출력하는 샘플링/홀딩 증폭 회로를 포함한다. 본 발명에 따르면, 최종 출력신호의 해상도 확장이 가능하고, 부가적인 회로에 의하여 기존의 전류셀 구동 방식의 변환기 출력단에 발생하는 글리치의 영향을 최소화함으로써 소모 전류를 줄일 수 있다. 디지털-아날로그 변환기, 전류셀 구동, 해상도, 확장
Abstract:
PURPOSE: A quadrature modulation transmitter is provided to reduce the power consumption and to overcome the mismatch problem in comparison with a heterodyne type transmitter or a digital IF type transmitter. CONSTITUTION: A quadrature modulation transmitter includes a digital processing block(410) and an analog processing block(420). The digital processing block(410) receives an I channel data, a Q channel data and a clock signal, modulates the I channel data or the inverse data of the I channel data into a first analog signal through the I channel DAC in response to the I clock signal and modulates the Q channel data or the inverse data of the Q channel data into a second analog signal through the Q channel DAC in response to the switching of the Q clock signal. And, the analog processing block(420) receives the first and the second analog signals from the digital processing block(410), adds the first analog signal to the second analog signal, transfers the added signal to the RF signal region through the combining process and transmits the transferred signal with amplifying the transferred signal.