參數(shù)資料
型號(hào): AD9648BCPZRL7-125
廠(chǎng)商: Analog Devices Inc
文件頁(yè)數(shù): 19/44頁(yè)
文件大小: 0K
描述: IC ADC 14BIT 125MSPS 64LFCSP
標(biāo)準(zhǔn)包裝: 750
位數(shù): 14
采樣率(每秒): 125M
數(shù)據(jù)接口: LVDS,并聯(lián),串行,SPI
轉(zhuǎn)換器數(shù)目: 2
電壓電源: 模擬和數(shù)字
工作溫度: -40°C ~ 85°C
安裝類(lèi)型: 表面貼裝
封裝/外殼: 64-VFQFN 裸露焊盤(pán),CSP
供應(yīng)商設(shè)備封裝: 64-LFCSP-VQ(9x9)
包裝: 帶卷 (TR)
輸入數(shù)目和類(lèi)型: 4 個(gè)單端,2 個(gè)差分
AD9648
Rev. 0 | Page 26 of 44
Input Common Mode
The analog inputs of the AD9648 are not internally dc-biased.
Therefore, in ac-coupled applications, the user must provide a
dc bias externally. Setting the device so that VCM = AVDD/2 is
recommended for optimum performance, but the device can
function over a wider range with reasonable performance, as
An on-board, common-mode voltage reference is included in
the design and is available from the VCM pin. The VCM pin
must be decoupled to ground by a 0.1 F capacitor, as described
0
10
20
30
40
50
60
70
80
90
100
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
S
NR/
S
F
DR
(
d
BF
S
/d
Bc)
INPUT COMMON-MODE VOLTAGE (V)
SFDR (dBc)
SNR (dBFS)
09975-
072
Figure 43. SNR/SFDR vs. Input Common-Mode Voltage,
fIN = 70 MHz, fS = 125 MSPS
Differential Input Configurations
Optimum performance is achieved while driving the AD9648 in a
differential input configuration. For baseband applications, the
AD8138, ADA4937-2, and ADA4938-2 differential drivers provide
excellent performance and a flexible interface to the ADC.
The output common-mode voltage of the ADA4938-2 is easily
set with the VCM pin of the AD9648 (see Figure 44), and the
driver can be configured in a Sallen-Key filter topology to
provide band limiting of the input signal.
AVDD
VIN
76.8
120
0.1F
33
33
10pF
200
200
90
ADA4938
ADC
VIN–x
VIN+x
VCM
09975-
050
Figure 44. Differential Input Configuration Using the ADA4938-2
For baseband applications below ~10 MHz where SNR is a key
parameter, differential transformer-coupling is the recommended
input configuration. An example is shown in Figure 45. To bias
the analog input, the VCM voltage can be connected to the
center tap of the secondary winding of the transformer.
2V p-p
49.9
0.1F
R
C
ADC
VCM
VIN+x
VIN–x
09975-
051
Figure 45. Differential Transformer-Coupled Configuration
The signal characteristics must be considered when selecting
a transformer. Most RF transformers saturate at frequencies
below a few megahertz (MHz). Excessive signal power can also
cause core saturation, which leads to distortion.
At input frequencies in the second Nyquist zone and above, the
noise performance of most amplifiers is not adequate to achieve
the true SNR performance of the AD9648. For applications above
~10 MHz where SNR is a key parameter, differential double balun
coupling is the recommended input configuration (see Figure 46).
An alternative to using a transformer-coupled input at frequencies
in the second Nyquist zone is to use the AD8352 differential driver.
An example is shown in Figure 47. See the AD8352 data sheet
for more information.
ADC
R
0.1F
2V p-p
VCM
C
R
0.1F
S
0.1F
25
25
S
PA
P
VIN+x
VIN–x
09975-
053
Figure 46. Differential Double Balun Input Configuration
AD8352
0
0
CD
RD
RG
0.1F
16
1
2
3
4
5
11
0.1F
10
14
0.1F
8, 13
VCC
200
200
ANALOG INPUT
R
C
ADC
VCM
VIN+x
VIN–x
09975-
054
Figure 47. Differential Input Configuration Using the AD8352
相關(guān)PDF資料
PDF描述
AD9649BCPZRL7-80 IC ADC 14BIT 80MSPS 32LFCSP
AD9653BCPZRL7-125 IC ADC 16BIT 125MSPS SRL 48LFCSP
AD9707BCPZRL7 IC DAC TX 14BIT 175MSPS 32-LFCSP
AD9709ASTZRL IC DAC 8BIT DUAL 125MSPS 48LQFP
AD9715BCPZ IC DAC DUAL 10BIT LO PWR 40LFCSP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD9649 制造商:AD 制造商全稱(chēng):Analog Devices 功能描述:14-Bit, 20/40/65/80 MSPS, 1.8 V Analog-to-Digital Converter
AD9649-20EBZ 功能描述:數(shù)據(jù)轉(zhuǎn)換 IC 開(kāi)發(fā)工具 14 Bit 20 Msps ADC RoHS:否 制造商:Texas Instruments 產(chǎn)品:Demonstration Kits 類(lèi)型:ADC 工具用于評(píng)估:ADS130E08 接口類(lèi)型:SPI 工作電源電壓:- 6 V to + 6 V
AD9649-20EBZ1 制造商:AD 制造商全稱(chēng):Analog Devices 功能描述:14-Bit, 20/40/65/80 MSPS 1.8 V Analog-to-Digital Converter
AD9649-40EBZ 功能描述:數(shù)據(jù)轉(zhuǎn)換 IC 開(kāi)發(fā)工具 14 Bit 40 Msps ADC RoHS:否 制造商:Texas Instruments 產(chǎn)品:Demonstration Kits 類(lèi)型:ADC 工具用于評(píng)估:ADS130E08 接口類(lèi)型:SPI 工作電源電壓:- 6 V to + 6 V
AD9649-40EBZ1 制造商:AD 制造商全稱(chēng):Analog Devices 功能描述:14-Bit, 20/40/65/80 MSPS 1.8 V Analog-to-Digital Converter