• <small id="wsvr6"><sup id="wsvr6"><ins id="wsvr6"></ins></sup></small>
  • <nobr id="wsvr6"><small id="wsvr6"></small></nobr>
    參數(shù)資料
    型號(hào): AD6653
    廠商: Analog Devices, Inc.
    英文描述: IF Diversity Receiver
    中文描述: IF分集接收機(jī)
    文件頁數(shù): 27/80頁
    文件大小: 1998K
    代理商: AD6653
    AD6653
    If the internal reference of the AD6653 is used to drive multiple
    converters to improve gain matching, the loading of the reference
    by the other converters must be considered. Figure 54 depicts
    how the internal reference voltage is affected by loading.
    Rev. 0 | Page 27 of 80
    .0
    0
    –1.25
    0
    2
    LOAD CURRENT (mA)
    R
    –0.25
    –0.50
    –0.75
    –1.00
    0.5
    1.0
    1.5
    VREF = 0.5V
    VREF = 1.0V
    0
    Figure 54. VREF Accuracy vs. Load
    External Reference Operation
    The use of an external reference may be necessary to enhance
    the gain accuracy of the ADC or improve thermal drift charac-
    teristics. Figure 55 shows the typical drift characteristics of the
    internal reference in both 1.0 V and 0.5 V modes.
    2.5
    –2.5
    –40
    TEMPERATURE (°C)
    R
    2.0
    1.5
    1.0
    0.5
    0
    –0.5
    –1.0
    –1.5
    –2.0
    –20
    0
    20
    40
    60
    80
    0
    Figure 55. Typical VREF Drift
    When the SENSE pin is tied to AVDD, the internal reference
    is disabled, allowing the use of an external reference. An internal
    reference buffer loads the external reference with an equivalent
    6 kΩ load (see Figure 18). The internal buffer generates the
    positive and negative full-scale references for the ADC core.
    Therefore, the external reference must be limited to a maximum
    of 1.0 V.
    CLOCK INPUT CONSIDERATIONS
    For optimum performance, the AD6653 sample clock inputs,
    CLK+ and CLK, should be clocked with a differential signal.
    The signal is typically ac-coupled into the CLK+ and CLK pins
    via a transformer or capacitors. These pins are biased internally
    (see Figure 56) and require no external bias.
    1.2V
    AVDD
    2pF
    2pF
    CLK–
    CLK+
    0
    Figure 56. Equivalent Clock Input Circuit
    Clock Input Options
    The AD6653 has a very flexible clock input structure. Clock input
    can be a CMOS, LVDS, LVPECL, or sine wave signal. Regardless
    of the type of signal being used, the clock source jitter is of the
    most concern, as described in the Jitter Considerations section.
    Figure 57 and Figure 58 show two preferred methods for clocking
    the AD6653 (at clock rates up to 625 MHz). A low jitter clock
    source is converted from a single-ended signal to a differential
    signal, using an RF transformer. The back-to-back Schottky diodes
    across the transformer secondary limit clock excursions into the
    AD6653 to approximately 0.8 V p-p differential. This helps prevent
    the large voltage swings of the clock from feeding through to other
    portions of the AD6653 while preserving the fast rise and fall
    times of the signal, which are critical to low jitter performance.
    0.1μF
    0.1μF
    0.1μF
    0.1μF
    SCHOTTKY
    DIODES:
    HSMS2822
    CLOCK
    INPUT
    50
    100
    CLK–
    CLK+
    ADC
    AD6653
    Mini-Circuits
    ADT1–1WT, 1:1Z
    XFMR
    0
    Figure 57. Transformer-Coupled Differential Clock (Up to 200 MHz)
    0.1μF
    0.1μF
    1nF
    CLOCK
    INPUT
    1nF
    50
    CLK–
    CLK+
    ADC
    AD6653
    SCHOTTKY
    DIODES:
    HSMS2822
    0
    Figure 58. Balun-Coupled Differential Clock (Up to 625 MHz)
    相關(guān)PDF資料
    PDF描述
    AD6653-125EBZ IF Diversity Receiver
    AD6653BCPZ-125 IF Diversity Receiver
    AD6653BCPZ-150 IF Diversity Receiver
    AD6655BCPZ-1251 IF Diversity Receiver
    AD6655 IF Diversity Receiver
    相關(guān)代理商/技術(shù)參數(shù)
    參數(shù)描述
    AD6653-125EBZ 制造商:Analog Devices 功能描述:Evaluation Board For AD6653 制造商:Analog Devices 功能描述:EVAL BD FOR AD6653 - Bulk 制造商:Analog Devices 功能描述:KIT EVALUATION BOARD AD6653
    AD6653-150EBZ 制造商:Analog Devices 功能描述:EVAL BD FOR AD6653 - Bulk
    AD6653BCPZ-125 制造商:Analog Devices 功能描述:IF DIVERSITY RCVR 64LFCSP EP - Trays 制造商:Rochester Electronics LLC 功能描述: 制造商:Analog Devices 功能描述:IC RECEIVER IF DIVERSITY LFCSP64
    AD6653BCPZ-150 制造商:Analog Devices 功能描述:IF DIVERSITY RCVR 64LFCSP EP - Trays 制造商:Analog Devices 功能描述:IC RECEIVER IF DIVERSITY LFCSP64 制造商:Analog Devices 功能描述:IC, RECEIVER, IF DIVERSITY, LFCSP64
    AD6654 制造商:Analog Devices 功能描述:- Bulk