参数资料
型号: EVAL-AD7946CBZ
厂商: Analog Devices Inc
文件页数: 7/24页
文件大小: 0K
描述: BOARD EVALUATION FOR AD7946
标准包装: 1
系列: PulSAR®
ADC 的数量: 1
位数: 14
采样率(每秒): 500k
数据接口: 串行
输入范围: 0 ~ 5.5 V
在以下条件下的电源(标准): 19mW @ 500kSPS,5 V
工作温度: -40°C ~ 85°C
已用 IC / 零件: AD7946
已供物品: 板,CD
相关产品: AD7946BCPZRL7TR-ND - IC ADC 14BIT 500KSPS 10-LFCSP
AD7946BCPZRL-ND - IC ADC 14BIT 500KSPS 10-LFCSP
AD7946BRMZRL7-ND - IC ADC 14BIT 500KSPS 10-MSOP
AD7946BRMZ-ND - IC ADC 14BIT 500KSPS SAR 10-MSOP
AD7946
Rev. A | Page 15 of 24
POWER SUPPLY
The AD7946 is specified at 4.5 V to 5.5 V. It uses two power
supply pins: a core supply VDD and a digital input/output
interface supply VIO. VIO allows direct interface with any
logic between 1.8 V and VDD. To reduce the supplies needed,
the VIO and VDD can be tied together. The AD7946 is
independent of power supply sequencing between VIO and
VDD. Additionally, it is very insensitive to power supply
variations over a wide frequency range, as shown in Figure 29,
which represents PSRR over frequency.
FREQUENCY (kHz)
P
S
RR
(dB)
04656-029
50
40
30
60
90
80
70
10
1
100
1k
10k
VDD = 5V
Figure 29. PSRR vs. Frequency
The AD7946 powers down automatically at the end of each
conversion phase and, therefore, the power scales linearly with
the sampling rate, as shown in Figure 30. This makes the part
ideal for low sampling rate (even a few Hz) and low battery-
powered applications.
04
65
6
-05
1
0.001
0.1
1
0.01
10
100
1000
10
100
1k
10k
100k
1M
SAMPLING RATE (SPS)
OP
E
R
A
T
ING
CUR
RE
NT
(
A
)
VIO
VDD = 5V
Figure 30. Operating Currents vs. Sampling Rate
SUPPLYING THE ADC FROM THE REFERENCE
For simplified applications, the AD7946, with its low operating
current, can be supplied directly using the reference circuit
shown in Figure 31. The reference line can be driven by one of
the following:
The system power supply directly.
A reference voltage with enough current output capability,
such as the ADR43x.
A reference buffer, such as the AD8031 or AD8603,
which can also filter the system power supply, as shown
AD8603
AD7946
VIO
REF
(NOTE 1)
VDD
10F
1F
10k
1k
47k
5V
1F
04
65
6
-03
1
NOTES
1. OPTIONAL REFERENCE BUFFER AND FILTER
Figure 31. Example of Application Circuit
SINGLE-SUPPLY APPLICATION
Figure 32 shows a typical 14-bit single-supply application. There
are different challenges to doing a single-supply, high resolution
design, and the ADA4841 addresses these nicely. The combina-
tion of low noise, low power, wide input range, rail-to-rail output,
and high speed make the ADA4841 a perfect driver solution for
low power, single-supply 14-bit ADCs, such as the AD7946. In a
single-supply system, one of the main challenges is to use the
amplifier in buffer mode to have the lowest output noise and
still preserve linearity compatible with the ADC. Rail-to-rail
input amplifiers usually have higher noise than the ADA4841
and cannot be used on their entire input range in buffer mode
because of the nonlinear region around the crossover point of
their input stage. The ADA4841, which has no crossover region
but has a wide linear input range from ground to 1 V below
positive rail, solves this issue, as shown in Figure 32, where it
can accept the 0 V to 4.096 V input range with a supply as low
as 5.2 V. This supply allows using a small, low dropout, low
temperature drift ADR364 reference voltage. Note that, like any
rail-to-rail output amplifier at the low end of its output range
close to ground, the ADA4841 can exhibit some nonlinearity on
a small region of approximately 25 mV from ground. The
ADA4841 drives a 1-pole, low-pass filter. This filter limits the
already very low noise contribution from the amplifier to the
AD7946.
相关PDF资料
PDF描述
MIC2015-0.8YML TR IC DISTRIBUTION SW 0.8A 6-MLF
RBA10DTKT-S288 CONN EDGECARD 20POS .125 EXTEND
HCC10DRYS CONN EDGECARD 20POS DIP .100 SLD
HBC08DRAS CONN EDGECARD 16POS R/A .100 SLD
GEC50DRXS CONN EDGECARD 100PS DIP .100 SLD
相关代理商/技术参数
参数描述
EVAL-AD7946SDZ 功能描述:BOARD EVAL FOR AD7946 RoHS:否 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-AD7949CBZ 制造商:Analog Devices 功能描述:EVAL BOARD 8 CH 250KSPS 14BIT ADC IC. - Bulk
EVAL-AD7949EDZ 功能描述:BOARD EVAL AD7949 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-AD7951EDZ 功能描述:BOARD EVAL FOR AD7951 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-AD7960FMCZ 制造商:Analog Devices 功能描述:AD7960 18BIT PULSAR DIFF ADC 制造商:Analog Devices 功能描述:EVAL BOARD, AD7960 ADC, Silicon Manufacturer:Analog Devices, Silicon Core Number:AD7960, Kit Application Type:Data Converter, Application Sub Type:ADC, Kit Contents:Eval Board AD7960,, Features:(Not Applicable)