参数资料
型号: AD9216-105PCB
厂商: Analog Devices, Inc.
英文描述: 10-Bit, 65/80/105 MSPS Dual A/D Converter
中文描述: 10位,65/80/105 MSPS双通道的A / D转换器
文件页数: 14/20页
文件大小: 298K
代理商: AD9216-105PCB
AD9216
Preliminary Technical Data
help reduce the peak transient current required from the output
stage of the driving source. Also, a small shunt capacitor can be
placed across the inputs to provide dynamic charging currents.
This passive network will create a low-pass filter at the ADC’s
input; therefore, the precise values are dependant on the
application. In IF under sampling applications, any shunt
capacitors should be removed. In combination with the driving
source impedance, they would limit the input bandwidth. For
best dynamic performance, the source impedances driving
VIN+ and VIN- should be matched such that common-mode
settling errors are symmetrical. These errors will be reduced by
the common-mode rejection of the ADC.
Rev. PrD
Page 14 of 20
6/15/2004
Figure 4.
Switched Capacitor Input
An internal differential reference buffer creates positive and
negative reference voltages, REFT and REFB, respectively, that
define the span of the ADC core. The output common-mode of
the reference buffer is set to midsupply, and the REFT and
REFB voltages and span are defined as follows:
(
REF
V
AVDD
2
1
REFT
+
=
)
(
)
REF
)
=
V
AVDD
REFB
=
2
(
REFT
1
REF
V
2
REFB
2
Span
×
×
=
It can be seen from the equations above that the REFT and
REFB voltages are symmetrical about the mid-supply voltage
and, by definition, the input span is twice the value of the V
REF
voltage.
The internal voltage reference can be pin-strapped to fixed
values of 0.5 V or 1.0 V, or adjusted within the same range as
discussed in the Internal Reference Connection section.
Maximum SNR performance will be achieved with the
AD9216 set to the largest input span of
2 V
. The relative SNR degradation will be 3 dB when
changing from 2 V
P-P
mode to 1 V
P-P
mode.
The SHA may be driven from a source that keeps the signal
peaks within the allowable range for the selected reference
voltage. The minimum and maximum common-mode input
levels are defined as follows:
2
V
(
VCM
REF
MIN
=
)
2
V
AVDD
VCM
REF
MAX
+
=
The minimum common-mode input level allows the AD9216 to
accommodate ground-referenced inputs. Although optimum
performance is achieved with a differential input, a single-
ended source may be driven into VIN+ or VIN- . In this
configuration, one input will accept the signal, while the
opposite input should be set to mid-scale by connecting it to an
appropriate reference. For example, a 2 V
P-P
signal may be
applied to VIN+ while a 1 V reference is applied to VIN- . The
AD9216 will then accept an input signal varying between 2 V
and 0 V. In the single-ended configuration, distortion
performance may degrade significantly as compared to the
differential case. However, the effect will be less noticeable at
lower input frequencies and in the lower speed grade models
(AD9216-65 and AD9216-80).
Differential Input Configurations
As previously detailed, optimum performance will be achieved
while driving the AD9216 in a differential input configuration.
For base band applications, the AD8138 differential driver
provides excellent performance and a flexible interface to the
ADC. The output common-mode voltage of the AD8138 is
easily set to AVDD/2, and the driver can be configured in a
Sallen-Key filter topology to provide band limiting of the input
signal.
At input frequencies in the second Nyquist zone and above, the
performance of most amplifiers will not be adequate to achieve
the true performance of the AD9216. This is especially true in
IF under sampling applications where frequencies in the 70
MHz to 200 MHz range are being sampled. For these
applications, differential transformer coupling is the
recommended input configuration, as shown in Figure 5.
Figure 5.
Differential Transformer Coupling
The signal characteristics must be considered when selecting a
transformer. Most RF transformers will saturate at frequencies
below a few MHz, and excessive signal power can also cause
core saturation, which leads to distortion.
Single-Ended Input Configuration
A single-ended input may provide adequate performance in
AD9216
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AD9216-105PCBZ 功能描述:BOARD EVAL FOR AD9216 105MSPS 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
AD9216-40PCB 制造商:AD 制造商全称:Analog Devices 功能描述:10-Bit, 65/80/105 MSPS Dual A/D Converter
AD9216-65 制造商:AD 制造商全称:Analog Devices 功能描述:10-Bit, 65/80/105 MSPS Dual A/D Converter
AD9216-65PCB 制造商:AD 制造商全称:Analog Devices 功能描述:10-Bit, 65/80/105 MSPS Dual A/D Converter
AD9216-80 制造商:AD 制造商全称:Analog Devices 功能描述:10-Bit, 65/80/105 MSPS Dual A/D Converter