参数资料
型号: AD7714YRZ
厂商: Analog Devices Inc
文件页数: 11/40页
文件大小: 0K
描述: IC ADC 24BIT SIGMA-DELTA 24SOIC
标准包装: 31
位数: 24
采样率(每秒): 1k
数据接口: DSP,MICROWIRE?,QSPI?,串行,SPI?
转换器数目: 1
功率耗散(最大): 7mW
电压电源: 模拟和数字
工作温度: -40°C ~ 105°C
安装类型: 表面贴装
封装/外壳: 24-SOIC(0.295",7.50mm 宽)
供应商设备封装: 24-SOIC W
包装: 管件
输入数目和类型: 3 个差分,单极;3 个差分,双极;5 个伪差分,单极;5 个伪差分,双极
配用: EVAL-AD7714-3EBZ-ND - BOARD EVAL FOR AD7714
2
AD7714
REV. C
–19–
CIRCUIT DESCRIPTION
The AD7714 is a sigma-delta A/D converter with on-chip digi-
tal filtering, intended for the measurement of wide dynamic
range, low frequency signals such as those in weigh-scale, pres-
sure transducer, industrial control or process control applica-
tions. It contains a sigma-delta (or charge-balancing) ADC, a
calibration microcontroller with on-chip static RAM, a clock
oscillator, a digital filter and a bidirectional serial communica-
tions port. The part consumes only 500
A of power supply
current and features a standby mode which requires only 10
A,
making it ideal for battery-powered or loop-powered instru-
ments. The part comes in two versions, the AD7714-5, which is
specified for operation from a nominal +5 V analog supply
(AVDD), and the AD7714-3, which is specified for operation
from a nominal +3.3 V analog supply. Both versions can be
operated with a digital supply (DVDD) voltage of either +3.3 V
or +5 V. AD7714Y grade parts operate with a nominal AVDD
of 3 V or 5 V and can be operated with a digital supply voltage
of either 3 V or 5 V.
The part contains three programmable-gain fully differential
analog input channels that can be reconfigured as five pseudo-
differential inputs. The gain range on all channels is from 1 to
128, allowing the part to accept unipolar signals of between
0 mV to +20 mV and 0 V to +2.5 V. In bipolar mode, the part
handles genuine bipolar signals of
±20 mV and quasi-bipolar
signals up to
±2.5 V when the reference input voltage equals
+2.5 V. With a reference voltage of +1.25 V, the input ranges
are from 0 mV to +10 mV to 0 V to +1.25 V in unipolar mode,
while in bipolar mode, the part handles genuine bipolar signals
of
±10 mV and quasi-bipolar signals up to ±1.25 V.
The part employs a sigma-delta conversion technique to realize
up to 24 bits of no missing codes performance. The sigma-delta
modulator converts the sampled input signal into a digital pulse
train whose duty cycle contains the digital information. The
programmable gain function on the analog input is also
incorporated in this sigma-delta modulator with the input sam-
pling frequency of the modulator being modified to give the
higher gains. A sinc
3 digital low-pass filter processes the output
of the sigma-delta modulator and updates the output register at
a rate determined by the first notch frequency of this filter. The
output data can be read from the serial port randomly or peri-
odically at any rate up to the output register update rate. The
first notch of this digital filter, its –3 dB frequency and its out-
put rate can be programmed via the filter high and filter low
registers. With a master clock frequency of 2.4576 MHz, the
programmable range for this first notch frequency and output
rate is from 4.8 Hz to 1.01 kHz giving a programmable range
for the –3 dB frequency of 1.26 Hz to 265 Hz.
The basic connection diagram for the part is shown in Figure 2.
This shows both the AVDD and DVDD pins of the AD7714 being
driven from the analog +3 V or +5 V supply. Some applications
will have AVDD and DVDD driven from separate supplies. In the
connection diagram shown, the AD7714’s analog inputs are
configured as three fully differential inputs. The part is set up
for unbuffered mode on the these analog inputs. An AD780,
precision +2.5 V reference, provides the reference source for the
part. On the digital side, the part is configured for three-wire
operation with
CS tied to DGND. A quartz crystal or ceramic
resonator provides the master clock source for the part. It may
be necessary to connect capacitors on the crystal or resonator to
ensure that it does not oscillate at overtones of its fundamental
operating frequency. The values of capacitors will vary depend-
ing on the manufacturer’s specifications.
SCLK
MCLK IN
DGND
DVDD
SYNC
RESET
DRDY
CS
MCLK OUT
POL
DIN
DOUT
AIN1
AGND
AIN2
AIN6
AIN3
AIN5
AIN4
REF IN(+)
STANDBY
REF IN(–)
AVDD
BUFFER
AD7714
0.1 F
10 F
ANALOG
GROUND
DIFFERENTIAL
ANALOG INPUT 3
DIFFERENTIAL
ANALOG INPUT 2
DIFFERENTIAL
ANALOG INPUT 1
DIGITAL
GROUND
0.1 F
10 F
VOUT
VIN
GND
AD780
ANALOG
+5V SUPPLY
ANALOG
+5V SUPPLY
DATA
READY
RECEIVE
(READ)
SERIAL
DATA
SERIAL
CLOCK
CRYSTAL OR
CERAMIC
RESONATOR
+5V
Figure 2. Basic Connection Diagram
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相关代理商/技术参数
参数描述
AD7714YRZ 制造商:Analog Devices 功能描述:IC ADC 24-BIT SIGMA DELTA
AD7714YRZ-REEL 功能描述:IC ADC 24BIT SIGMA-DELTA 24SOIC RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 系列:- 位数:12 采样率(每秒):300k 数据接口:并联 转换器数目:1 功率耗散(最大):75mW 电压电源:单电源 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC(0.295",7.50mm 宽) 供应商设备封装:24-SOIC 包装:带卷 (TR) 输入数目和类型:1 个单端,单极;1 个单端,双极
AD7714YRZ-REEL7 功能描述:IC ADC 24BIT SIGMA-DELTA 24SOIC RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 系列:- 位数:12 采样率(每秒):300k 数据接口:并联 转换器数目:1 功率耗散(最大):75mW 电压电源:单电源 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC(0.295",7.50mm 宽) 供应商设备封装:24-SOIC 包装:带卷 (TR) 输入数目和类型:1 个单端,单极;1 个单端,双极
AD7715 制造商:AD 制造商全称:Analog Devices 功能描述:3 V/5 V, 450 uA 16-Bit, Sigma-Delta ADC