- 您现在的位置：买卖IC网 > PDF目录17039 > EVAL-AD7622CBZ (Analog Devices Inc)BOARD EVALUATION FOR AD7622 PDF资料下载
参数资料
| 型号： | EVAL-AD7622CBZ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 10/28页 |
| 文件大小： | 0K |
| 描述： | BOARD EVALUATION FOR AD7622 |
| 标准包装： | 1 |
| 系列： | PulSAR® |
| ADC 的数量： | 1 |
| 位数： | 16 |
| 采样率（每秒）： | 2M |
| 数据接口： | 串行，并联 |
| 输入范围： | ±VREF |
| 在以下条件下的电源（标准）： | 70mW @ 2MSPS |
| 工作温度： | -40°C ~ 85°C |
| 已用 IC / 零件： | AD7622 |
| 已供物品： | 板 |
| 相关产品： | AD7622BSTZ-ND - IC ADC 16BIT DIFFERENTIAL 48LQFP AD7622BCPZ-ND - IC ADC 16BIT DIFFERENTL 48-LFCSP AD7622BSTZRL-ND - IC ADC 16BIT DIFFERENTL 48-LQFP AD7622BCPZRL-ND - IC ADC 16BIT DIFFERENTL 48-LFCSP |
第1页第2页第3页第4页第5页第6页第7页第8页第9页当前第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页
AD7622
Rev. 0 | Page 18 of 28
DRIVER AMPLIFIER CHOICE
Although the AD7622 is easy to drive, the driver amplifier
needs to meet the following requirements:
For multichannel, multiplexed applications, the driver
amplifier and the AD7622 analog input circuit must be
able to settle for a full-scale step of the capacitor array at an
16-bit level (0.0015%). In the amplifier’s data sheet, settling
at 0.1% to 0.01% is more commonly specified. This could
differ significantly from the settling time at a 16-bit level
and should be verified prior to driver selection. The
AD8021 op amp, which combines ultralow noise and high
gain bandwidth, meets this settling time requirement even
when used with gains up to 13.
The noise generated by the driver amplifier needs to be
kept as low as possible to preserve the SNR and transition
noise performance of the AD7622. The noise coming from
the driver is filtered by the AD7622 analog input circuit
1-pole, low-pass filter made by RIN and CIN or by the
external filter, if one is used. The SNR degradation due
to the amplifier is
()
()
+
=
+
2
π
2
π
45
20log
N
3dB
N
3dB
LOSS
Ne
f
Ne
f
SNR
where:
f–3dB is the input bandwidth of the AD7622 (50 MHz) or
the cutoff frequency of the input RC filter shown in Figure 24
(3.9 MHz), if one is used.
N is the noise factor of the amplifier (1 in buffer
configuration).
eN+ and eN are the equivalent input voltage noise densities
of the op amps connected to IN+ and IN, in nV/√Hz.
This approximation can be used when the resistances used
around the amplifier are small. If larger resistances are
used, their noise contributions should also be root-sum
squared.
For instance, when using op amps with an equivalent input
noise density of 2.1 nV/√Hz, such as the AD8021, with a
noise gain of 1 when configured as a buffer, degrades the
SNR by only 0.1 dB when using the RC filter in Figure 24,
and by 1.3 dB without it.
The driver needs to have a THD performance suitable to
that of the AD7622. Figure 14 gives the THD vs. frequency
that the driver should exceed.
The AD8021 meets these requirements and is appropriate for
almost all applications. The AD8021 needs a 10 pF external
compensation capacitor that should have good linearity as an
NPO ceramic or mica type. Moreover, the use of a noninverting
1 gain arrangement is recommended and helps to obtain the
best signal-to-noise ratio.
The AD8022 can also be used when a dual version is needed
and a gain of 1 is present. The AD829 is an alternative in
applications where high frequency (above 100 kHz) performance is
not required. In applications with a gain of 1, an 82 pF
compensation capacitor is required. The AD8610 is an option
when low bias current is needed in low frequency applications.
Refer to Table 8 for some recommended op amps.
Table 8. Recommended Driver Amplifiers
Amplifier
Typical Application
Very low noise, low distortion, low power,
low frequency
Very low noise, low frequency
Very low noise, high frequency
Very low noise, high frequency, dual
Low bias current, low frequency, single/dual
Single-to-Differential Driver
For applications using unipolar analog signals, a single-ended-
to-differential driver, as shown in Figure 28, allows for a
differential input into the part. This configuration, when
provided an input signal of 0 to VREF, produces a differential
±VREF with midscale at VREF/2. The 1-pole filter using R = 15 Ω
and C = 2.7nF provides a corner frequency of 3.9 MHz.
If the application can tolerate more noise, the AD8139
differential driver can be used.
AD8021
ANALOG INPUT
(UNIPOLAR 0V TO 2.048V)
AD8021
IN+
IN–
AD7622
REF
10F
15
100nF
2.7nF
U2
U1
10pF
5k
590
0
602
3-
041
Figure 28. Single-Ended-to-Differential Driver Circuit
(Internal Reference Buffer Used)
相关PDF资料 |
PDF描述 |
|---|---|
| RBC08DREN-S93 | CONN EDGECARD 16POS .100 EYELET |
| RSC05DREH-S93 | CONN EDGECARD 10POS .100 EYELET |
| 0210490995 | CABLE JUMPER 1.25MM .127M 29POS |
| RMC05DREH-S93 | CONN EDGECARD 10POS .100 EYELET |
| MLG1005SR20J | INDUCTOR MULTILAYER .20UH 0402 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| EVAL-AD7622EDZ | 功能描述:BOARD EVAL FOR AD7622 RoHS:是 类别:编程器，开发系统 >> 评估板 - 模数转换器 (ADC) 系列:* 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:- ADC 的数量:1 位数:12 采样率（每秒）:94.4k 数据接口:USB 输入范围:±VREF/2 在以下条件下的电源（标准）:- 工作温度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板，软件 |
| EVAL-AD7623CB | 制造商:Analog Devices 功能描述:EVAL KIT FOR 16BIT, 1.33 MSPS PULSAR ADC - Trays |
| EVAL-AD7623CBZ | 功能描述:BOARD EVALUATION FOR AD7623 RoHS:是 类别:编程器，开发系统 >> 评估板 - 模数转换器 (ADC) 系列:PulSAR® 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:- ADC 的数量:1 位数:12 采样率（每秒）:94.4k 数据接口:USB 输入范围:±VREF/2 在以下条件下的电源（标准）:- 工作温度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板，软件 |
| EVAL-AD7623EDZ | 功能描述:BOARD EVAL FOR AD7623 RoHS:是 类别:编程器，开发系统 >> 评估板 - 模数转换器 (ADC) 系列:* 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:- ADC 的数量:1 位数:12 采样率（每秒）:94.4k 数据接口:USB 输入范围:±VREF/2 在以下条件下的电源（标准）:- 工作温度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板，软件 |
| EVAL-AD7625EDZ | 功能描述:数据转换 IC 开发工具 Eval Board 16-BIT 5MSPS ADC I.C RoHS:否 制造商:Texas Instruments 产品:Demonstration Kits 类型:ADC 工具用于评估:ADS130E08 接口类型:SPI 工作电源电压:- 6 V to + 6 V |
发布紧急采购，3分钟左右您将得到回复。