Abstract:
PURPOSE: A gradient-based approach to sample-time mismatch error calibration in a two-channel time-interleaved analog-to-digital converter is provided to correct a phase error at a 2-channel TIADC(time interleaved analog to digital converter) system which is independent from a Nyquist zone. CONSTITUTION: An input signal is converted into first and second digital signals in order to provide two sets of ADC outputs. A sample time error is estimated from the first and second digital signals. A correction signal is determined from a sample time error regardless of a Nyquist zone which is occupied by an input signal. The correction signal is applied to the converting step. The step of determining the correction signal includes a step of estimating a gradient of the sample time error. [Reference numerals] (AA) Size(db); (BB) Input signal spectrum in a first Nyquist zone
Abstract:
PURPOSE: A method for correcting errors at digital outputs and a folding-interpolation analog to digital converter using the same are provided to eliminate detected errors by detecting errors at a digital output. CONSTITUTION: An error correction unit is composed of a lower code estimating unit(210) and an error estimating unit(220). The lower code estimating unit estimates which one of a maximum value or a minimum value of a lower binary code corrects the lower binary code of an analog signal by referring to a first bit of the lower binary code. The lower code estimating unit estimates the minimum value of the lower binary code using the lower binary code of the analog signal according to the first bit of the lower binary code.
Abstract:
A differential current switch driving circuit of a digital to analog converter is provided to suppress timing skew between first and second differential signals by equalizing conversion timing of the first and second differential signals. A first differential signal generation unit(120) generates a first differential signal by inverting and delaying a digital signal received through a data input terminal by using a first inverter and a transmission gate. A second differential signal generation unit(130) generates a second differential signal by inverting and delaying the digital signal received through the data input terminal by using second and third inverters. A data latch unit(140) latches the first and second differential signals and outputs the latched signals to a differential current switch.
Abstract:
본 발명은 미드-트레드 방식에 비해 전체 동작 속도가 떨어지지 않으면서 종래의 미드-트레드 방식으로 출력하지 못했던 디지털 코드 영역을 출력할 수 있는, 개선된 코딩 방식의 파이프라인 아날로그-디지털 변환기를 제공하기 위한 것으로, 이를 위해 본 발명은 제1 내지 제N(N은 2 이상의 정수) 아날로그-디지털 변환 스테이지들이 직렬로 연결된 파이프라인 아날로그-디지털 변환기에 있어서, 상기 제1 내지 제N-1 아날로그-디지털 변환 스테이지들에서는 미드-트레드 방식에 따라 코딩을 수행하고, 상기 제N 아날로그-디지털 변환 스테이지에서는 미드-라이즈 방식에 따라 코딩을 수행하도록 구성된다.
Abstract:
PURPOSE: A sigma-delta analog-digital converter is provided to increase overall resolution. CONSTITUTION: An operational amplifier(10) connects an input terminal to a fourth node(D) and connects an output terminal to an output end. A sampling capacitor(20) connects one end to a second node, connects the other end to a third node and samples. An integral capacitor(30) connects one end to the fourth node, connects the other end to an output terminal of the operational amplifier and feedbacks. A first switching circuit(40) switches sampling operation of a switched-capacitor integrator according to a sampling clock. A second switching circuit(50) switches integration operation of the switched-capacitor integrator according to an integration clock. A third switching circuit(70) switches reset operation of the switched-capacitor integrator according to a reset clock.
Abstract:
PURPOSE: A radio transmission device and method using a digital-analog converter are provided to minimize the use of an analog device while maximizing the signal to noise ratio or the spurious-free dynamic range of an output signal. CONSTITUTION: A digital signal generator(110) creates a base band digital signal having bandwidth less than half of digital-analog conversion sampling frequency about data which is transmitted. A digital-to-analog conversion part(130) changes the base band digital signal into an analog signal. A frequency band determining part(150) determines the frequency band of an image signal which is fitted to predetermined signal-noise ratio in a output spectrum of the analog signal. A band pass filter(170) changeably passes through the analog signal which belongs to the frequency band. An analog transmission part(190) transmits the analog signal which is passed through a transmission antenna.
Abstract:
본 발명은 시스템이 원래 가지고 있는 오프셋을 허용 가능한 오프셋으로 자동 조정할 수 있도록 하는 오프셋 자동 보상 장치 및 방법에 관한 것이다. 이를 위해, 본 발명은 시스템이 인에이블되면, 스위칭부를 턴온시켜 시스템이 가지고 있는 자체 오프셋 전류를 오프셋 센싱 및 비교부로 우회시킴과 동시에 오프셋 생성부에서 시스템으로 포지티브 오프셋 발생을 위한 포지티브 오프셋 전류를 인가하고, 오프셋 센싱 및 비교부는 스위칭부를 통해 우회되는 오프셋 전류를 센싱하여, 센싱된 오프셋 전류를 허용 가능한 범위의 오프셋 전류와 비교한 후, 비교결과에 따라 로우 또는 하이 레벨의 출력 신호를 생성하여 오프셋 생성부로 인가하며, 오프셋 생성부는 오프셋 센싱 및 비교부로부터 인가되는 출력 신호에 따라 시스템으로 네거티브 오프셋 전류를 인가하여 오프셋 전류를 보상하되, 오프셋 전류가 허용 가능한 범위로 조정되어 오프셋 센싱 및 비교부로부터 인가되는 출력 신호가 없게 되면, 오프셋 생성부는 그 순간의 포지티브 오프셋 전류량과 네거티브 오프셋 전류량을 유지시키도록 구성되는 것이 바람직하다. 이에 따라, 본 발명은 시스템이 원래 가지고 있는 오프셋을 허용 가능한 오프셋으로 자동 조정할 수 있게 된다.
Abstract:
PURPOSE: A delta-sigma analog digital converter is provided to obtain a wide operation region by converting a dynamic range through the control of the current which is fed back. CONSTITUTION: A modulator(110) generates an over-sampled PDM(Pulse Density Modulated) signal by converting an analog input current. A post process unit generates digital data corresponding to the analog input current by decreasing a sampling ratio of the generated PDM signal. The post process unit generates a selection signal to control the dynamic range of the modulator. The modulator includes a plurality of current source which generates the current with different sizes. The modulator includes a current supply unit(510) which adds the current generated from the selected current source to the analog input current.
Abstract:
전압제어발진기 기반의 N차 아날로그 디지털 변환기는 N 개의 컨버팅부, 멀티플렉서를 포함한다. N 개의 컨버팅부는 기준 클럭 신호가 N(N은 2이상의 자연수) 분주된 제1 내지 제N 클럭 신호에 따라 각각의 샘플링 레이트로 아날로그 입력 신호가 샘플링된 제1 내지 제N 개 샘플신호의 전압 레벨에 기초한 N 개의 디지털 신호를 각각 출력한다. 멀티플렉서는 제어 클럭 신호에 응답하여 상기 N 개의 디지털 신호들 중 하나를 선택하여 출력한다. 따라서 여러 주파수 대역에서 높은 신호 대 잡음비를 갖는다.
Abstract:
An analog to digital converter having a fast conversion function is provided to synchronize each operation signals of an analog to digital converter to perform a fast conversion operation. An analog to digital converter(100) having a fast conversion function includes an integrating unit(110) storing an analog signal and a feedback analog signal according to a plurality of switching signals. The integrating unit integrates the stored analog signal. A quantizing unit(120) quantizes an analog signal integrated in the integrating unit to a digital signal with a plurality of bits. A data weighted averaging unit(130) averages the digital signal applied from the quantizing unit through a multi-step bit shifting process according to a predetermined reference signal. A first register(140) converts a current level of the digital signal applied from the data weighted averaging unit to a predetermined current level according to the predetermined reference signal. A digital to analog converter(150) converts the digital signal applied from the first register to the feedback analog signal according to the switching signal.