- 您现在的位置：买卖IC网 > PDF目录10667 > AD7719BRUZ (Analog Devices Inc)IC ADC 16BIT 24BIT DUAL 28-TSSOP PDF资料下载
参数资料
| 型号： | AD7719BRUZ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 30/40页 |
| 文件大小： | 0K |
| 描述： | IC ADC 16BIT 24BIT DUAL 28-TSSOP |
| 标准包装： | 50 |
| 位数： | 16/24 |
| 采样率（每秒）： | 105 |
| 数据接口： | DSP，MICROWIRE?，QSPI?，串行，SPI? |
| 转换器数目： | 2 |
| 功率耗散（最大）： | 4.5mW |
| 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： | 28-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 28-TSSOP |
| 包装： | 管件 |
| 输入数目和类型： | 3 个差分，单极；3 个差分，双极 |
| 产品目录页面： | 778 (CN2011-ZH PDF) |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页当前第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页
REV. A
AD7719
–36–
Pressure Measurement
One typical application of the AD7719 is pressure measure-
ment. Figure 19 shows the AD7719 used with a pressure
transducer, the BP01 from Sensym.
The pressure transducer is arranged in a bridge network and
gives a differential output voltage between its OUT(+) and
OUT(–) terminals. With rated full-scale pressure (in this case
300 mmHg) on the transducer, the differential output voltage is
3 mV/V of the input voltage (i.e., the voltage between its IN(+)
and IN(–) terminals).
Assuming a 5 V excitation voltage, the full-scale output range
from the transducer is 15 mV. The excitation voltage for the
bridge can be used to directly provide the reference for the ADC
as the reference input range includes the supplies. Alternatively,
a suitable resistor divider can be implemented that allows the
full dynamic range of the input to be utilized in these applica-
tion. This implementation is fully ratiometric, so variations in
the excitation voltage do not introduce errors in the system.
Choosing resistor values of 20 k
and 12 k as per Figure 19
give a 1.875 V reference voltage for the AD7719 when the exci-
tation voltage is 5 V.
AD7719
IN+
OUT+
OUT–
IN–
20k
12k
EXCITATION VOLTAGE = 5V
AVDD
DVDD
AIN1
AIN2
REFIN1(+)
P1
PWRGND
DGND
AGND
REFIN2(–)
Figure 19. Pressure Measurement Using AD7719
Using the part with a programmed gain of 128 results in the
full-scale input span of the AD7719 being 15 mV, which corre-
sponds with the output span from the transducer.
A second key advantage to using the AD7719 in transducer
based applications is that the on-chip low-side power switch can
be fully utilized in low power applications. The low-side power
switch is connected in series with the cold side of the bridge. In
normal operation, the switch is closed and measurements can be
taken from the bridge. In applications where power is of con-
cern, the AD7719 can be put in low power mode, substantially
reducing the power burned in the application. In addition to
this, the power switch can be opened while in low power mode
thus avoiding the unnecessary burning of power in the front end
transducer. When the AD7719 is taken back out of power-down
and the power switch is closed, the user should ensure that the
front end circuitry is fully settled before attempting a read from
the AD7719.
The circuit in Figure 20 shows a method that utilizes all three
pseudodifferential input channels on the AD7719 main channel
to temperature-compensate a pressure transducer.
5V
OUT(+)
OUT(–)
IN(–)
IN(+)
I1
I2
PRESSURE
BRIDGE
XTAL1
XTAL2
IOUT1
6.25k
AVDD
REFIN(+)
REFIN(–)
AIN2
AIN1
AIN3
AIN4
AGND
AD7719
250
Figure 20. Temperature-Compensating a Pressure
Transducer
In this application, pseudodifferential input channel AIN1/AIN4
is used to measure the bridge output while pseudodifferential
channels AIN2/AIN4 and AIN3/AIN4 measure the voltage
across the bridge. The voltage measured across the bridge will
vary proportionally with temperature, and the delta in this volt-
age can be used to temperature-compensate the output of the
pressure bridge.
Temperature Measurement
The AD7719 is also useful in temperature measurement applica-
tions; Figure 21 shows an RTD temperature measurement
application. In this application, the transducer is an RTD (resistive
temperature device), a PT100. The arrangement is a 4-lead RTD
configuration. There are voltage drops across the lead resistances
RL1 and RL4, but these simply shift the common-mode voltage.
There is no voltage drop across lead resistances RL2 and RL3 as
the input current to the AD7719 is very low, looking into a high
input impedance buffer. RCM is included to shift the analog input
voltage to ensure that it lies within the common-mode range
(AGND + 100 mV to AVDD – 100 mV) of the ADC. In the
application shown, the on-chip 200 A current source provides the
excitation current for the PT100 and also generates the reference
voltage for the AD7719 via the 12.5 k
resistor. Variations in
the excitation current do not affect the circuit as both the input
voltage and the reference voltage vary ratiometrically with the
excitation current. However, the 12.5 k
resistor must have a low
temperature coefficient to avoid errors in the reference voltage
over temperature.
相关PDF资料 |
PDF描述 |
|---|---|
| HA1-4902-2 | IC COMPARATOR QUAD PREC 16-DIP |
| LTC1417IGN#PBF | IC A/D CONV 14BIT SAMPLNG 16SSOP |
| AD7732BRUZ | IC ADC 24BIT 2-CH 28-TSSOP |
| LTC1418CG#PBF | IC A/D CONV 14BIT SRL&PAR 28SSOP |
| AD7574JNZ | IC ADC 8BIT CMOS 5V 18-DIP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AD7719BRUZ-REEL | 功能描述:IC ADC 16BIT 24BIT DUAL 28TSSOP 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 |
| AD7719BRUZ-REEL7 | 功能描述:IC ADC 16BIT 24BIT DUAL 28TSSOP 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 |
| AD7719BRZ | 功能描述:IC ADC 16BIT 24BIT DUAL 28SOIC 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 |
| AD7720 | 制造商:AD 制造商全称:Analog Devices 功能描述:CMOS Sigma-Delta Modulator |
| AD7720BRU | 功能描述:IC MODULATOR SIGMA-DELTA 28TSSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 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 |
发布紧急采购，3分钟左右您将得到回复。