Digitally driven analog test signal generator
    1.
    发明授权
    Digitally driven analog test signal generator 失效
    数字驱动模拟测试信号发生器

    公开(公告)号:US6163286A

    公开(公告)日:2000-12-19

    申请号:US89496

    申请日:1998-06-02

    IPC分类号: G01R31/28 H03M3/04 H03M1/66

    CPC分类号: G01R31/2841

    摘要: A high performance test signal generator uses a digital to analog converter which converts an N-bit digital signal, such as provided by a computer waveform generator or by a CDROM into an M-bit upsampled digital signal. The M-bit digital signal is applied to an M-bit digital to analog converter to produce an analog output signal. The analog output signal is sampled and fed back across, the discrete time/continuous time interface to the input of the conversion circuit. The test signal generator has very low power consumption yet meets very strict noise and linearity requirements. The test signal generator can be used for testing seismic sensors such as geophones or hydrophones.

    摘要翻译: 高性能测试信号发生器使用数模转换器,其将诸如由计算机波形发生器或CDROM提供的N位数字信号转换为M位上采样的数字信号。 M位数字信号被施加到M位数模转换器以产生模拟输出信号。 模拟输出信号被采样并反馈到离散的时间/连续时间接口到转换电路的输入端。 测试信号发生器具有非常低的功耗,但满足非常严格的噪声和线性要求。 测试信号发生器可用于测试地震检波器,如地震检波器或水听器。

    Multibit digital to analog converter with feedback across the discrete
time/continuous time interface
    2.
    发明授权
    Multibit digital to analog converter with feedback across the discrete time/continuous time interface 失效
    具有跨越离散时间/连续时间接口的反馈的多位数模转换器

    公开(公告)号:US6130633A

    公开(公告)日:2000-10-10

    申请号:US89489

    申请日:1998-06-02

    IPC分类号: H03M3/04 H03M1/66

    CPC分类号: H03M3/50

    摘要: A multi-bit digital to analog converter uses both discrete time and continuous time processing to produce an analog output signal. The analog output signal is sampled and fed back across the discrete time/continuous time interface to the input of the conversion circuit. In one implementation, the discrete time processing uses an integrator chain of switched capacitor integrators and a switched capacitor low pass filter. The continuous time processor is a 2 pole low pass filter. A finite impulse response filter can precede the discrete time processing. A plurality of analog output sampling arrangements can be selectively applied accommodate a variety of operational conditions.

    摘要翻译: 多位数模转换器使用离散时间和连续时间处理来产生模拟输出信号。 模拟输出信号被采样并通过离散时间/连续时间接口反馈到转换电路的输入端。 在一个实现中,离散时间处理使用开关电容器积分器的积分器链和开关电容器低通滤波器。 连续时间处理器是2极低通滤波器。 有限脉冲响应滤波器可以在离散时间处理之前。 可以选择性地应用多个模拟输出采样装置来适应各种操作条件。

    One bit digital to analog converter with relaxed filtering requirements
    3.
    发明授权
    One bit digital to analog converter with relaxed filtering requirements 失效
    一个位数字模拟转换器,具有放松的滤波要求

    公开(公告)号:US6124816A

    公开(公告)日:2000-09-26

    申请号:US89497

    申请日:1998-06-02

    IPC分类号: H03M3/04 H03M1/66

    CPC分类号: H03M3/508

    摘要: A digital to analog converter utilizes two discrete time processing stages, such as switched capacitor integrator circuits, operating at different sampling rates when converting the digital input signal to an analog signal. Use of two different sampling rates relaxes the requirements on antialias filters used in the continuous time processing.

    摘要翻译: 数模转换器利用两个离散的时间处理级,例如开关电容积分电路,在将数字输入信号转换为模拟信号时,以不同的采样率工作。 使用两种不同的采样率可以放松对连续时间处理中使用的抗混叠滤波器的要求。

    Digital to analog converter for correcting for non-linearities in analog
devices
    4.
    发明授权
    Digital to analog converter for correcting for non-linearities in analog devices 失效
    用于校正模拟设备中非线性的数模转换器

    公开(公告)号:US6124815A

    公开(公告)日:2000-09-26

    申请号:US89495

    申请日:1998-06-02

    IPC分类号: H03M3/04 H03M1/66

    CPC分类号: H03M3/352 H03M3/50

    摘要: A integrated circuit digital to analog converter converts an M-bit digital signal to an analog output signal. The analog output signal can be used to drive external devices such as an off-chip driver. The output of the external device is sampled and fed back across the discrete time/continuous time interface on the chip to the input of the analog to digital converter. Taking the feedback point after the external device ensures relatively high performance for noise and linearity using relatively low performance components, both on and off the chip.

    摘要翻译: 集成电路数模转换器将M位数字信号转换为模拟输出信号。 模拟输出信号可用于驱动外部设备,如片外驱动器。 对外部器件的输出进行采样,并将芯片上的离散时间/连续时间接口反馈到模数转换器的输入端。 在外部器件之后采取反馈点,使用相对较低性能的器件(芯片上和芯片上),确保噪声和线性度的相对较高的性能。

    Digital to analog converter having improved noise and linearity
performance
    5.
    发明授权
    Digital to analog converter having improved noise and linearity performance 失效
    具有改善的噪声和线性性能的数模转换器

    公开(公告)号:US6124814A

    公开(公告)日:2000-09-26

    申请号:US89490

    申请日:1998-06-02

    IPC分类号: H03M3/04 H03M1/66

    CPC分类号: H03M3/368 H03M3/50

    摘要: A digital to analog converter converts an N-bit digital signal into an M-bit digital signal and provides the M-bit digital signal to a conversion circuit which converts the M-bit signal to an analog output signal. The analog output signal is sampled and fed back across the discrete time/continuous time interface to the input of the conversion circuit. An interpolation filter is used to increase the apparent sampling rate of the incoming N-bit signal.

    摘要翻译: 数模转换器将N位数字信号转换为M位数字信号,并将M位数字信号提供给将M位信号转换为模拟输出信号的转换电路。 模拟输出信号被采样并通过离散时间/连续时间接口反馈到转换电路的输入端。 内插滤波器用于增加输入N位信号的表观采样率。

    One bit digital to analog converter with feedback across the discrete
time/continuous time interface
    6.
    发明授权
    One bit digital to analog converter with feedback across the discrete time/continuous time interface 失效
    一个位数字到模拟转换器,具有跨越离散时间/连续时间接口的反馈

    公开(公告)号:US6121909A

    公开(公告)日:2000-09-19

    申请号:US89488

    申请日:1998-06-02

    IPC分类号: H03M3/02 H03M1/66

    CPC分类号: H03M3/50

    摘要: A 1-bit digital to analog converter uses both discrete time and continuous time processing to produce an analog output signal. The analog output signal is sampled and fed back across the discrete time/continuous time interface to the input of the conversion circuit. In one implementation, the discrete time processing uses an integrator chain of switched capacitor integrators and a switched capacitor low pass filter. The continuous time processor is a 2 pole low pass filter. A finite impulse response filter can precede the discrete time processing. A plurality of analog output sampling arrangements can be selectively applied accommodate a variety of operational conditions.

    摘要翻译: 1位数模转换器使用离散时间和连续时间处理来产生模拟输出信号。 模拟输出信号被采样并通过离散时间/连续时间接口反馈到转换电路的输入端。 在一个实现中,离散时间处理使用开关电容器积分器的积分器链和开关电容器低通滤波器。 连续时间处理器是2极低通滤波器。 有限脉冲响应滤波器可以在离散时间处理之前。 可以选择性地应用多个模拟输出采样装置来适应各种操作条件。

    Linear phase FIR sinc filter with multiplexing
    7.
    发明授权
    Linear phase FIR sinc filter with multiplexing 有权
    线性相位FIR sinc滤波器与多路复用

    公开(公告)号:US06321246B1

    公开(公告)日:2001-11-20

    申请号:US09153866

    申请日:1998-09-16

    IPC分类号: G06F1710

    摘要: A phase shifter is implemented using a polyphase filter. The filter is preferably a linear phase Finite Impulse Response (FIR) filter. The amount of delay imparted by the phase shifter is determined by a particular set of coefficients selected from a plurality of such coefficients. Storage requirements are reduced by taking advantage of symmetries in the coefficients for the filters. Memory requirements are further reduced by partitioning the polyphase filter into two polyphase filters and using one to set a rough delay amount and the other to set a fine delay amount between rough delay amount settings. The particular amount of delay may be set by an external synchronization signal.

    摘要翻译: 使用多相滤波器实现移相器。 滤波器优选为线性相位有限脉冲响应(FIR)滤波器。 由移相器给出的延迟量由从多个这样的系数中选择的一组特定系数确定。 通过利用滤波器​​的系数中的对称性来减少存储要求。 通过将多相滤波器分成两个多相滤波器并使用一个设置粗略延迟量,另一个设置粗略延迟量设置之间的精细延迟量,进一步减少存储器要求。 延迟的特定量可以由外部同步信号来设定。

    Sinc filter with selective decimation ratios
    9.
    发明授权
    Sinc filter with selective decimation ratios 有权
    具有选择性抽取比例的Sinc滤波器

    公开(公告)号:US06317765B1

    公开(公告)日:2001-11-13

    申请号:US09153862

    申请日:1998-09-16

    IPC分类号: G06F1717

    摘要: A decimation filter implements selective decimation ratios by arranging a plurality of sinc filters in different pipeline arrangements to produce the desired ratio. Power savings area achieved by implementing the sinc filters as FIR sinc filters and by implementing multiplications using look up tables. One approach uses a fixed first stage filter and one or more second stage sinc filters selected from the group comprising two 4th order, 5 tap sinc filters, a 4th order, 9 tap sinc filter; a 5th order, 6 tap sinc filter and a 6th order 7 tap sinc filter. The sinc filter is particularly useful applications in the field of data acquisition and particularly in the area of seismic sensing.

    摘要翻译: 抽取滤波器通过在不同的流水线布置中布置多个正弦滤波器来实现选择性抽取比,以产生期望的比率。 通过将sinc滤波器实现为FIR sinc滤波器并通过使用查找表来实现乘法而实现的省电区域。 一种方法使用固定的第一级滤波器和一个或多个第二级sinc滤波器,其选自包括两个4阶,5抽头sinc滤波器,第4级,9抽头sinc滤波器的组; 5号,6抽头sinc过滤器和6阶7抽头sinc过滤器。 sinc滤波器在数据采集领域尤其是在地震检测领域尤其有用。

    Correct carry bit generation
    10.
    发明授权
    Correct carry bit generation 失效
    正确的进位位产生

    公开(公告)号:US06243733B1

    公开(公告)日:2001-06-05

    申请号:US09153868

    申请日:1998-09-16

    IPC分类号: G06F738

    CPC分类号: G06F7/5443 G06F7/49947

    摘要: A multiply add carry (MAC) circuit correctly determines the value of a carry bit when an operation X*Y+Z is undertaken, where X, Y and Z are real numbers and where an accumulator and rounding are utilized. The circuit (1) determines if the product X*Y is negative, (2) determines if the value in the accumulator is negative, (3) determines if a round bit propagates all the way to the most significant bit (MSB) position, (4) determines if the result X*Y+Accumulator+round is negative; and (5) determines a correct carry bit based on the other determinations.

    摘要翻译: 当进行X * Y + Z操作时,乘法加法(MAC)电路正确地确定进位位的值,其中X,Y和Z是实数,并且使用累加器和舍入。 电路(1)确定乘积X * Y是否为负,(2)确定累加器中的值是否为负,(3)确定一个圆比特是否一直传播到最高有效位(MSB)位置, (4)确定结果X * Y +累加器+圆是否为负; 和(5)基于其他确定来确定正确的进位位。