參數資料
| 型號： | AD9752ARZ |
| 廠商： | Analog Devices Inc |
| 文件頁數： | 8/23頁 |
| 文件大小： | 0K |
| 描述： | IC DAC 12BIT 125MSPS 28-SOIC |
| 產品培訓模塊： | Data Converter Fundamentals DAC Architectures |
| 標準包裝： | 27 |
| 系列： | TxDAC® |
| 設置時間： | 35ns |
| 位數： | 12 |
| 數據接口： | 并聯(lián) |
| 轉換器數目： | 1 |
| 電壓電源： | 模擬和數字 |
| 功率耗散（最大）： | 220mW |
| 工作溫度： | -40°C ~ 85°C |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 28-SOIC（0.295"，7.50mm 寬） |
| 供應商設備封裝： | 28-SOIC W |
| 包裝： | 管件 |
| 輸出數目和類型： | 2 電流，單極；2 電流，雙極 |
| 采樣率（每秒）： | 125M |
| 產品目錄頁面： | 785 (CN2011-ZH PDF) |
REV. 0
AD9752
–16–
maintain optimum performance. Care should be taken to ensure
that the ground plane is uninterrupted over crucial signal paths.
On the digital side, this includes the digital input lines running
to the DAC as well as any clock signals. On the analog side, this
includes the DAC output signal, reference signal and the supply
feeders.
The use of wide runs or planes in the routing of power lines is
also recommended. This serves the dual role of providing a low
series impedance power supply to the part, as well as providing
some “free” capacitive decoupling to the appropriate ground
plane. It is essential that care be taken in the layout of signal and
power ground interconnects to avoid inducing extraneous volt-
age drops in the signal ground paths. It is recommended that all
connections be short, direct and as physically close to the pack-
age as possible in order to minimize the sharing of conduction
paths between different currents. When runs exceed an inch in
length, strip line techniques with proper termination resistor
should be considered. The necessity and value of this resistor
will be dependent upon the logic family used.
For a more detailed discussion of the implementation and
construction of high speed, mixed signal printed circuit boards,
refer to Analog Devices’ application notes AN-280 and
AN-333.
FREQUENCY – Hz
–30
–40
–100
1M
600k
AMPLITUDE
–
dBm
800k
–50
–60
–70
–80
–90
Figure 35a. Notch in Missing Bin at 750 kHz is Down
>60 dB. (Peak Amplitude + 0 dBm).
FREQUENCY – MHz
–30
–40
–100
5.15
4.85
AMPLITUDE
–
dBm
5
–50
–60
–70
–80
–90
–110
Figure 35b. Notch in Missing Bin at 5 MHz is Down
>60 dB. (Peak Amplitude + 0 dBm).
APPLICATIONS
VDSL Applications Using the AD9752
Very High Frequency Digital Subscriber Line (VDSL) technol-
ogy is growing rapidly in applications requiring data transfer
over relatively short distances. By using QAM modulation and
transmitting the data in multiple discrete tones, high data rates
can be achieved.
As with other multitone applications, each VDSL tone is ca-
pable of transmitting a given number of bits, depending on the
signal-to-noise ratio (SNR) in a narrow band around that tone.
The tones are evenly spaced over the range of several kHz to
10 MHz. At the high frequency end of this range, performance
is generally limited by cable characteristics and environmental
factors, such as external interferers. Performance at the lower
frequencies is much more dependent on the performance of the
components in the signal chain. In addition to in-band noise,
intermodulation from other tones can also potentially interfere
with the recovery of data for a given tone. The two graphs in
Figure 35 represent a 500 tone missing bin test vector, with
frequencies evenly spaced from 400 Hz to 10 MHz. This test is
very commonly done to determine if distortion will limit the
number of bits which can be transmitted in a tone. The test
vector has a series of missing tones around 750 kHz, which is
represented in Figure 35a and a series of missing tones around
5 MHz which is represented in Figure 35b. In both cases, the
spurious free range between the transmitted tones and the empty
bins is greater than 60 dB.
Using the AD9752 for Quadrature Amplitude Modulation
(QAM)
QAM is one of the most widely used digital modulation
schemes in digital communication systems. This modulation
technique can be found in FDM as well as spreadspectrum (i.e.,
CDMA) based systems. A QAM signal is a carrier frequency
that is modulated in both amplitude (i.e., AM modulation) and
phase (i.e., PM modulation). It can be generated by indepen-
dently modulating two carriers of identical frequency but with a
90
° phase difference. This results in an in-phase (I) carrier com-
ponent and a quadrature (Q) carrier component at a 90
° phase
shift with respect to the I component. The I and Q components
are then summed to provide a QAM signal at the specified car-
rier frequency.
A common and traditional implementation of a QAM modu-
lator is shown in Figure 36. The modulation is performed in the
analog domain in which two DACs are used to generate the
baseband I and Q components, respectively. Each component is
then typically applied to a Nyquist filter before being applied to
a quadrature mixer. The matching Nyquist filters shape and
limit each component’s spectral envelope while minimizing
intersymbol interference. The DAC is typically updated at the
QAM symbol rate or possibly a multiple of it if an interpolating
filter precedes the DAC. The use of an interpolating filter typi-
cally eases the implementation and complexity of the analog
filter, which can be a significant contributor to mismatches in
gain and phase between the two baseband channels. A quadra-
ture mixer modulates the I and Q components with in-phase
and quadrature phase carrier frequency and then sums the two
outputs to provide the QAM signal.
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| AD9752ARZRL | 功能描述:IC DAC 12BIT 125MSPS 28SOIC RoHS:是 類別:集成電路 (IC) >> 數據采集 - 數模轉換器 系列:TxDAC® 標準包裝:47 系列:- 設置時間:2µs 位數:14 數據接口:并聯(lián) 轉換器數目:1 電壓電源:單電源 功率耗散（最大）:55µW 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:28-SSOP（0.209"，5.30mm 寬） 供應商設備封裝:28-SSOP 包裝:管件 輸出數目和類型:1 電流，單極；1 電流，雙極 采樣率（每秒）:* |
| AD9752-EB | 制造商:Analog Devices 功能描述:Evaluation Board For AD9752 制造商:Analog Devices 功能描述:DEV TOOLS, EVAL BD FOR AD9752 - Bulk |
| AD9752-EBZ | 功能描述:BOARD EVAL FOR AD9752 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - 數模轉換器 (DAC) 系列:TxDAC® 產品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:1 系列:- DAC 的數量:4 位數:12 采樣率（每秒）:- 數據接口:串行，SPI? 設置時間:3µs DAC 型:電流/電壓 工作溫度:-40°C ~ 85°C 已供物品:板 已用 IC / 零件:MAX5581 |
| AD9753 | 制造商:AD 制造商全稱:Analog Devices 功能描述:Analog Devices: Data Converters: DAC 12-Bit, 10 ns to 100 ns Converters Selection Table |
| AD9753AST | 制造商:Analog Devices 功能描述:DAC 1-CH Segment 12-bit 48-Pin LQFP 制造商:Rochester Electronics LLC 功能描述:12-BIT, 300 MSPS TXDAC+ D/A CONVERTER - Tape and Reel 制造商:Analog Devices 功能描述:IC 12-BIT DAC |
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