參數(shù)資料
型號(hào): AD7357BRUZ-500RL7
廠商: Analog Devices Inc
文件頁(yè)數(shù): 6/21頁(yè)
文件大小: 0K
描述: IC ADC DUAL14BIT 4.2MSPS 16TSSOP
設(shè)計(jì)資源: DC-Coupled, Single-Ended-to-Differential Conversion Using AD8138 and AD7357 (CN0061)
標(biāo)準(zhǔn)包裝: 500
位數(shù): 14
采樣率(每秒): 4.2M
數(shù)據(jù)接口: DSP,MICROWIRE?,QSPI?,串行,SPI?
轉(zhuǎn)換器數(shù)目: 2
功率耗散(最大): 59mW
電壓電源: 單電源
工作溫度: -40°C ~ 85°C
安裝類(lèi)型: 表面貼裝
封裝/外殼: 16-TSSOP(0.173",4.40mm 寬)
供應(yīng)商設(shè)備封裝: 16-TSSOP
包裝: 帶卷 (TR)
輸入數(shù)目和類(lèi)型: 2 個(gè)差分,雙極
AD7357
Rev. B | Page 13 of 20
For ac applications, it is recommended to remove high frequency
components from the analog input signal by the use of an RC
low-pass filter on the analog input pins. In applications where
harmonic distortion and signal-to-noise ratio are critical, the
analog input should be driven from a low impedance source. Large
source impedances significantly affect the ac performance of the
ADC and may necessitate the use of an input buffer amplifier.
The choice of the op amp is a function of the particular
application.
When no amplifier is used to drive the analog input, the source
impedance should be limited to low values. The maximum source
impedance depends on the amount of THD that can be tole-
rated. The THD increases as the source impedance increases
and performance degrades. Figure 17 shows a graph of the
THD vs. the analog input signal frequency for various source
impedances.
–89
–87
–85
–83
–81
–79
–77
–75
–73
–71
–69
–67
–65
100
200
1000
1500
2000
2500
FREQUENCY (kHz)
T
HD
(
d
B)
10
33
50
100
07
75
7-
01
7
Figure 17. THD vs. Analog Input Frequency for Various Source Impedances
Figure 18 shows a graph of the THD vs. the analog input
frequency while sampling at 4.2 MSPS. In this case, the
source impedance is 33 Ω.
–90.0
–86.0
–82.0
–78.0
–74.0
–70.0
–66.0
0
1000
2000
3000
4000
5000
ANALOG INPUT FREQUENCY (kHz)
T
HD
(
d
B)
07
75
7–
11
8
Figure 18. THD vs. Analog Input Frequency
ANALOG INPUTS
Differential signals have some benefits over single-ended
signals, including noise immunity based on the device’s
common-mode rejection and improvements in distortion
performance. Figure 19 defines the fully differential input
of the AD7357.
VIN+
AD7357*
VIN–
VREF p-p
*ADDITIONAL PINS OMITTED FOR CLARITY.
COMMON
MODE
VOLTAGE
0
775
7-
03
4
Figure 19. Differential Input Definition
The amplitude of the differential signal is the difference
between the signals applied to the VIN+ and VIN pins in
each differential pair (VIN+ VIN). VIN+ and VIN should be
simultaneously driven by two signals each of amplitude VREF
that are 180° out of phase. This amplitude of the differential
signal is, therefore, –VREF to +VREF peak-to-peak regardless of
the common mode (CM).
CM is the average of the two signals and is, therefore, the
voltage on which the two inputs are centered.
CM = (VIN+ + VIN)/2
This results in the span of each input being CM ± VREF/2. This
voltage has to be set up externally. When setting up the CM,
ensure that that VIN+ and VIN remain within GND/VDD. When
a conversion takes place, CM is rejected, resulting in a virtually
noise free signal of amplitude –VREF to +VREF corresponding to
the digital codes of 0 to 16,383.
DRIVING DIFFERENTIAL INPUTS
Differential operation requires VIN+ and VIN to be driven simulta-
neously with two equal signals that are 180° out of phase. Because
not all applications have a signal preconditioned for differential
operation, there is often a need to perform a single-ended-to-
differential conversion.
Differential Amplifier
An ideal method of applying differential drive to the AD7357
is to use a differential amplifier such as the AD8138. This part
can be used as a single-ended-to-differential amplifier or as a
differential-to-differential amplifier. The AD8138 also provides
common-mode level shifting. Figure 20 shows how the AD8138
can be used as a single-ended-to-differential amplifier. The
positive and negative outputs of the AD8138 are connected to
the respective inputs on the ADC via a pair of series resistors
to minimize the effects of switched capacitance on the front
end of the ADC. The architecture of the AD8138 results in
outputs that are very highly balanced over a wide frequency
range without requiring tightly matched external components.
相關(guān)PDF資料
PDF描述
VI-2NW-CU-F4 CONVERTER MOD DC/DC 5.5V 200W
B250W48A106E1G IC DSP AUDIO 16BIT 48WLCSP
LTC2289CUP#PBF IC ADC DUAL 10BIT 80MSPS 64QFN
B250W48A106XXG IC PROCESSOR AUDIO 16BIT 48WLCSP
VI-2NW-CU-F2 CONVERTER MOD DC/DC 5.5V 200W
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7357BRUZ-RL 功能描述:IC ADC 14BITDUAL 4.MSPS 16TSSOP RoHS:是 類(lèi)別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 位數(shù):12 采樣率(每秒):300k 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):75mW 電壓電源:單電源 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:24-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數(shù)目和類(lèi)型:1 個(gè)單端,單極;1 個(gè)單端,雙極
AD7357WYRUZ 制造商:Analog Devices 功能描述:ADC Dual SAR 4.2Msps 14-bit Serial 16-Pin TSSOP 制造商:Analog Devices 功能描述:14-BIT DUAL DIFF SIMULT 5 MSPS ADC I.C. - Rail/Tube 制造商:Rochester Electronics LLC 功能描述: 制造商:Analog Devices 功能描述:IC ADC 14BIT SRL 5MSPS 16TSSOP 制造商:Analog Devices 功能描述:Analog to Digital Converters - ADC 14-Bit Dual Diff Simult 5 MSPS 制造商:Analog Devices 功能描述:14-Bit Dual Diff Simult 5 MSPS ADC I.C.
AD7357WYRUZ-RL 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 14-Bit Dual Diff Simult 5 MSPS RoHS:否 制造商:Analog Devices 通道數(shù)量: 結(jié)構(gòu): 轉(zhuǎn)換速率: 分辨率: 輸入類(lèi)型: 信噪比: 接口類(lèi)型: 工作電源電壓: 最大工作溫度: 安裝風(fēng)格: 封裝 / 箱體:
AD7357YRUZ 功能描述:IC ADC DUAL14BIT 4.2MSPS 16TSSOP RoHS:是 類(lèi)別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 位數(shù):14 采樣率(每秒):83k 數(shù)據(jù)接口:串行,并聯(lián) 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):95mW 電壓電源:雙 ± 工作溫度:0°C ~ 70°C 安裝類(lèi)型:通孔 封裝/外殼:28-DIP(0.600",15.24mm) 供應(yīng)商設(shè)備封裝:28-PDIP 包裝:管件 輸入數(shù)目和類(lèi)型:1 個(gè)單端,雙極
AD7357YRUZ-500RL7 功能描述:IC ADC DUAL14BIT 4.2MSPS 16TSSOP RoHS:是 類(lèi)別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 位數(shù):12 采樣率(每秒):300k 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):75mW 電壓電源:單電源 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:24-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數(shù)目和類(lèi)型:1 個(gè)單端,單極;1 個(gè)單端,雙極