参数资料
型号: EVAL-AD7641CBZ
厂商: Analog Devices Inc
文件页数: 7/28页
文件大小: 0K
描述: BOARD EVALUATION FOR AD7641
产品培训模块: ADC Applications
ADC Architectures
ADC DC/AC Performance
标准包装: 1
系列: PulSAR®
ADC 的数量: 1
位数: 18
采样率(每秒): 2M
数据接口: 串行
输入范围: ±2.5 V
在以下条件下的电源(标准): 2MSPS 带内部基准时为 75mW
工作温度: -40°C ~ 85°C
已用 IC / 零件: AD7641
已供物品:
相关产品: AD7641BSTZRL-ND - IC ADC 18BIT 2MSPS SAR 48-LQFP
AD7641BCPZRL-ND - IC ADC 18BIT 2MSPS SAR 48-LFCSP
AD7641BSTZ-ND - IC ADC 18BIT 2MSPS SAR 48-LQFP
AD7641BCPZ-ND - IC ADC 18BIT 2MSPS SAR 48-LFCSP
AD7641
Rev. 0 | Page 15 of 28
APPPLICATIONS INFORMATION
SW+
COMP
SW–
IN+
REF
REFGND
LSB
MSB
131,072C
65,536C
4C
2C
C
CONTROL
LOGIC
SWITCHES
CONTROL
BUSY
OUTPUT
CODE
CNVST
IN–
4C
2C
C
LSB
MSB
AGND
131,072C 65,536C
04
761
-02
1
Figure 21. ADC Simplified Schematic
CIRCUIT INFORMATION
The AD7641 is a very fast, low power, single-supply, precise
18-bit ADC using successive approximation architecture. The
AD7641 features different modes to optimize performances
according to the applications. In warp mode, the AD7641 is
capable of converting 2,000,000 samples per second (2 MSPS).
The AD7641 provides the user with an on-chip track-and-hold,
successive approximation ADC that does not exhibit any
pipeline or latency, making it ideal for multiple multiplexed
channel applications.
The AD7641 can operate from a single 2.5 V supply and
interface to either 5 V, 3.3 V, or 2.5 V digital logic. It is housed
in a 48-lead LQFP package or a tiny 48-lead LFCSP package,
which combines space savings with flexibility and allows the
AD7641 to be configured as either a serial or a parallel
interface. The AD7641 is pin-to-pin-compatible and is a
speed upgrade of the AD7674, AD7678, and AD7679.
CONVERTER OPERATION
The AD7641 is a successive approximation ADC based on a
charge redistribution DAC. Figure 21 shows the simplified
schematic of the ADC. The capacitive DAC consists of two
identical arrays of 16 binary weighted capacitors that are
connected to the two comparator inputs.
During the acquisition phase, terminals of the array tied to the
comparator’s input are connected to AGND via SW+ and SW.
All independent switches are connected to the analog inputs.
Therefore, the capacitor arrays are used as sampling capacitors
and acquire the analog signal on the IN+ and IN inputs. A
conversion phase is initiated once the acquisition phase is complete
and the CNVST input goes low. When the conversion phase
begins, SW+ and SW are opened first. The two capacitor
arrays are then disconnected from the inputs and connected to
the REFGND input. Therefore, the differential voltage between
the inputs (IN+ and IN) captured at the end of the acquisition
phase is applied to the comparator inputs, causing the
comparator to become unbalanced. By switching each element
of the capacitor array between REFGND and REF, the comparator
input varies by binary weighted voltage steps (VREF/2, VREF/4
throughVREF/131072). The control logic toggles these switches,
starting with the MSB first, to bring the comparator back into a
balanced condition. After the completion of this process, the
control logic generates the ADC output code and brings BUSY
output low.
MODES OF OPERATION
The AD7641 features three modes of operations: wideband
warp, warp, and normal. Each of these modes is more suitable
for specific applications.
The wideband warp (WARP = high, NORMAL = high) and
warp (WARP = high, NORMAL = low) modes allow the fastest
conversion rate of up to 2 MSPS. However, in these modes, the
full specified accuracy is guaranteed only when the time between
conversions does not exceed 1 ms. If the time between two
consecutive conversions is longer than 1 ms (for instance after
power-up), the first conversion result should be ignored. These
modes make the AD7641 ideal for applications where both high
accuracy and fast sample rates are required. Wideband warp
mode offers slightly improved linearity and THD over warp mode.
Normal mode (NORMAL = low, WARP = low) is the fastest
mode (1.5 MSPS) without any limitation on time between
conversions. This mode makes the AD7641 ideal for
asynchronous applications, such as data acquisition systems,
where both high accuracy and fast sample rates are required.
相关PDF资料
PDF描述
DC1571A-B BOARD SAR ADC LTC2382-16
DC1571A-A BOARD SAR ADC LTC2383-16
STD17W-5 WIRE & CABLE MARKERS
STD17W-T WIRE & CABLE MARKERS
EVAL-AD7612CBZ BOARD EVALUATION FOR AD7612
相关代理商/技术参数
参数描述
EVAL-AD7641EDZ 功能描述:BOARD EVAL FOR AD7641 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-AD7643CB 制造商:Analog Devices 功能描述:EVAL BD FOR AD7643 - Bulk
EVAL-AD7643CBZ 功能描述:BOARD EVALUATION FOR AD7643 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-AD7643EDZ 功能描述:BOARD EVAL FOR AD7643 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-AD7650CB 制造商:Analog Devices 功能描述:EVAL BD EVAL BD AD765X/AD766X/AD767X - Bulk