参数资料
| 型号： | AD679BJ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 3/16页 |
| 文件大小： | 0K |
| 描述： | IC ADC 14BIT SAMPLING 44-JLCC |
| 标准包装： | 1 |
| 位数： | 14 |
| 采样率（每秒）： | 128k |
| 数据接口： | 并联 |
| 转换器数目： | 2 |
| 功率耗散（最大）： | 745mW |
| 电压电源： | 模拟和数字，双 ± |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 44-LCC（J 形引线） |
| 供应商设备封装： | 44-JLCC（16.39x16.39） |
| 包装： | 管件 |
| 输入数目和类型： | 1 个单端，单极；1 个单端，双极 |
AD679
REV. D
–11–
and digital ground planes are also desirable, with a single inter-
connection point to minimize ground loops. Analog signals
should be routed as far as possible from digital signals and
should cross them at right angles.
The AD679 incorporates several features to help the user’s lay-
out. Analog pins (VEE, AIN, AGND, REFOUT, REFIN, BIPOFF,
VCC) are adjacent to help isolate analog from digital signals. In
addition, the 10 M
input impedance of AIN minimizes input
trace impedance errors. Finally, ground currents have been
minimized by careful circuit architecture. Current through
AGND is 200
A, with no code dependent variation. The cur-
rent through DGND is dominated by the return current for
DB7–DB0 and EOC.
SUPPLY DECOUPLING
The AD679 power supplies should be well filtered, well regu-
lated, and free from high frequency noise. Switching power sup-
plies are not recommended due to their tendency to generate
spikes that can induce noise in the analog system.
Decoupling capacitors should be used in very close layout prox-
imity between all power supply pins and analog ground. A 10
F
tantalum capacitor in parallel with a 0.1
F ceramic capacitor
provides adequate decoupling.
An effort should be made to minimize the trace length between
the capacitor leads and the respective converter power supply
and common pins. The circuit layout should attempt to locate
the AD679, associated analog input circuitry, and interconnec-
tions as far as possible from logic circuitry. A solid analog
ground plane around the AD679 isolates large switching ground
currents. For these reasons, the use of wire wrap circuit con-
struction is not recommended; careful printed circuit construc-
tion is preferred.
GROUNDING
If a single AD679 is used with separate analog and digital
ground planes, connect the analog ground plane to AGND and
the digital ground plane to DGND, keeping lead lengths as
short as possible. Then connect AGND and DGND together at
the AD679. If multiple AD679s are used or if the AD679 shares
analog supplies with other components, connect the analog and
digital returns together once at the power supplies rather than at
each chip. This prevents large ground loops, which inductively
couple noise and allow digital currents to flow through the ana-
log system.
USE OF EXTERNAL VOLTAGE REFERENCE
The AD679 features an on-chip voltage reference. For improved
gain accuracy over temperature, a high performance external
voltage reference may be used in place of the on-chip reference.
The AD586 and AD588 are popular references appropriate for
use with high resolution converters. The AD586 is a low cost
reference that utilizes a buried Zener architecture to provide low
noise and drift. The AD588 is a higher performance reference
that uses a proprietary implanted buried Zener diode in con-
junction with laser-trimmed thin-film resistors for low offset and
low drift.
Figure 7 shows the use of the AD586 with the AD679 in a bipolar
input mode. Over the 0
°C to 70°C range, the AD586 L-grade
exhibits less than a 2.25 mV output change from its initial value
at 25
°C. REF
IN (Pin 9) scales its input by a factor of two; thus,
this change becomes effectively 4.5 mV. When applied to the
AD679, this results in a total gain drift of 0.09% FSR, which is
an improvement over the on-chip reference performance of
0.11% FSR. A noise-reduction capacitor, CN, has been shown.
This capacitor reduces the broadband noise of the AD586 out-
put, thereby optimizing the overall ac and dc performance of the
AD679.
Figure 7. Bipolar Input with Gain and Offset Trims
Figure 8 shows the AD679 in unipolar input mode with the
AD588 reference. The AD588 output is accurate to 0.65 mV
from its value at 25
°C over the 0°C to 70°C range. This results
in a 0.06% FSR total gain drift for the AD679, a substantial im-
provement over the on-chip reference performance of 0.11%
FSR. A noise-reduction network on Pins 4, 6, and 7 has been
shown. The 1
F capacitors form low-pass filters with the inter-
nal resistance of the AD588 Zener and amplifier cells and exter-
nal resistance. This reduces the high frequency (to 1 MHz)
noise of the AD588, providing optimum ac and dc performance
of the AD679.
REFIN
Figure 8. Unipolar Input with Gain and Offset Trims
相关PDF资料 |
PDF描述 |
|---|---|
| AD7111BQ | IC DAC LOGARITHMIC 16-CDIP |
| AD7170BCPZ-REEL7 | IC ADC 12BIT SIGMA-DELTA 10LFCSP |
| AD7171BCPZ-REEL7 | IC ADC 16BIT SER 125HZ 10LFCSP |
| AD7190BRUZ-REEL | IC ADC 2CH 24BIT W/PGA 24TSSOP |
| AD7191BRUZ | IC ADC 2CH 24B SD 24TSSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AD679JD | 功能描述:IC ADC 14BIT SAMPLING 28-CDIP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:250 系列:- 位数:12 采样率（每秒）:1.8M 数据接口:并联 转换器数目:1 功率耗散（最大）:1.82W 电压电源:模拟和数字 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-LQFP 供应商设备封装:48-LQFP（7x7） 包装:管件 输入数目和类型:2 个单端，单极 |
| AD679JN | 功能描述:IC ADC 14BIT 128KSPS 28-DIP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1 系列:- 位数:14 采样率（每秒）:83k 数据接口:串行，并联 转换器数目:1 功率耗散（最大）:95mW 电压电源:双 ± 工作温度:0°C ~ 70°C 安装类型:通孔 封装/外壳:28-DIP（0.600"，15.24mm） 供应商设备封装:28-PDIP 包装:管件 输入数目和类型:1 个单端，双极 |
| AD679JNZ | 功能描述:IC ADC 14BIT 128KSPS 28-DIP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 其它有关文件:TSA1204 View All Specifications 标准包装:1 系列:- 位数:12 采样率（每秒）:20M 数据接口:并联 转换器数目:2 功率耗散（最大）:155mW 电压电源:模拟和数字 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-TQFP 供应商设备封装:48-TQFP（7x7） 包装:Digi-Reel® 输入数目和类型:4 个单端，单极；2 个差分，单极 产品目录页面:1156 (CN2011-ZH PDF) 其它名称:497-5435-6 |
| AD679KD | 功能描述:IC ADC 14BIT SAMPLING 28-CDIP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:250 系列:- 位数:12 采样率（每秒）:1.8M 数据接口:并联 转换器数目:1 功率耗散（最大）:1.82W 电压电源:模拟和数字 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-LQFP 供应商设备封装:48-LQFP（7x7） 包装:管件 输入数目和类型:2 个单端，单极 |
| AD679KN | 制造商:Analog Devices 功能描述:ADC Single Flash 128ksps 14-bit Parallel 28-Pin PDIP W |
发布紧急采购，3分钟左右您将得到回复。