数据搜索系统,热门电子元器件搜索
Selected language     Chinese  ▼
部分名称
         详细搜索


AD8319 Datasheet(数据表) 10 Page - Analog Devices

部件型号  AD8319
说明  1 MHz to 10 GHz, 40 dB Log Detector/Controller
下载  20 Pages
Scroll/Zoom Zoom In 100% Zoom Out
制造商  AD [Analog Devices]
网页  http://www.analog.com
标志 

 10 page
background image
AD8319
Rev. A | Page 10 of 20
THEORY OF OPERATION
The AD8319 is a 5-stage demodulating logarithmic amplifier,
specifically designed for use in RF measurement and power
control applications at frequencies up to 10 GHz. A block
diagram is shown in Figure 21. Sharing much of its design with
the AD8318 logarithmic detector/controller, the AD8319
maintains tight intercept variability vs. temperature over a
40 dB range. Additional enhancements over the AD8318, such
as reduced RF burst response time of 8 ns to 10 ns, 22 mA
supply current, and board space requirements of only 2 mm ×
3 mm add to the low cost and high performance benefits found
in the AD8319.
GAIN
BIAS
SLOPE
DET
DET
DET
DET
INHI
INLO
IV
VOUT
VSET
CLPF
TADJ
VPSO
COMM
IV
Figure 21. Block Diagram
A fully differential design, using a proprietary, high speed
SiGe process, extends high frequency performance. Input INHI
receives the signal with a low frequency impedance of nominally
500 Ω in parallel with 0.7 pF. The maximum input with ±1 dB
log conformance error is typically 0 dBm (re: 50 Ω). The noise
spectral density referred to the input is 1.15 nV/√Hz, which is
equivalent to a voltage of 118 μV rms in a 10.5 GHz bandwidth
or a noise power of −66 dBm (re: 50 Ω). This noise spectral
density sets the lower limit of the dynamic range. However, the
low end accuracy of the AD8319 is enhanced by specially
shaping the demodulating transfer characteristic to partially
compensate for errors due to internal noise. The common pin,
COMM, provides a quality low impedance connection to the
printed circuit board (PCB) ground. The package paddle, which
is internally connected to the COMM pin, should also be
grounded to the PCB to reduce thermal impedance from the
die to the PCB.
The logarithmic function is approximated in a piecewise
fashion by five cascaded gain stages. (For a more comprehensive
explanation of the logarithm approximation, refer to the AD8307
data sheet.) The cells have a nominal voltage gain of 9 dB each
and a 3 dB bandwidth of 10.5 GHz. Using precision biasing, the
gain is stabilized over temperature and supply variations. The
overall dc gain is high due to the cascaded nature of the gain
stages. An offset compensation loop is included to correct for
offsets within the cascaded cells. At the output of each of the
gain stages, a square-law detector cell is used to rectify the signal.
The RF signal voltages are converted to a fluctuating differential
current having an average value that increases with signal level.
Along with the five gain stages and detector cells, an additional
detector is included at the input of the AD8319, providing a
40 dB dynamic range in total. After the detector currents are
summed and filtered, the following function is formed at the
summing node
ID × log10(VIN/VINTERCEPT)
(1)
where:
ID is the internally set detector current.
VIN is the input signal voltage.
VINTERCEPT is the intercept voltage (that is, when VIN = VINTERCEPT,
the output voltage would be 0 V, if it were capable of going to 0 V).




HTML 页

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20 


数据表 下载



相关电子零件

部件型号部件说明Html View制造商
ADL55191 MHz to 10 GHz 50 dB Dual Log Detector/Controller 1 2 3 4 5 MoreAnalog Devices
AD83171 MHz to 10 GHz 50 dB Log Detector/Controller 1 2 3 4 5 MoreAnalog Devices
AD83191 MHz to 10 GHz 40 dB Log Detector/Controller 1 2 3 4 5 MoreAnalog Devices
AD8314_06100 MHz to 2.7 GHz 45 dB RF Detector/Controller 1 2 3 4 5 MoreAnalog Devices
AD8318_061 MHz to 8 GHz 60 dB Logarithmic Detector/Controller 1 2 3 4 5 MoreAnalog Devices
AD8312_0550 MHz to 3.5 GHz 45 dB RF Detector 1 2 3 4 5 MoreAnalog Devices
AD8313_040.1 GHz to 2.5 GHz 70 dB Logarithmic Detector/Controller 1 2 3 4 5 MoreAnalog Devices
AD8354_051 MHz to 2.7 GHz RF Gain Block 1 2 3 4 5 MoreAnalog Devices
ADL5330_0510 MHz to 3 GHz VGA with 60 dB Gain Control Range 1 2 3 4 5 MoreAnalog Devices

链接网址

ALLDATASHEET是否为您带来帮助?  [ DONATE ]  

关于 Alldatasheet    |   广告服务   |   联系我们   |   隐私政策   |   书签   |   链接交换   |   制造商名单
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  , Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp  |   Russian : Alldatasheetru.com
Korean : Alldatasheet.co.kr   |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com  |   Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl