- 您現在的位置：買賣IC網 > PDF目錄373914 > AD7714* (Analog Devices, Inc.) 3 V/5 V. CMOS. 500 uA Signal Conditioning ADC PDF資料下載
參數資料
| 型號： | AD7714* |
| 廠商： | Analog Devices, Inc. |
| 英文描述： | 3 V/5 V. CMOS. 500 uA Signal Conditioning ADC |
| 中文描述： | 3 V / 5號五的CMOS。 500微安ADC的信號調理 |
| 文件頁數： | 19/40頁 |
| 文件大小： | 306K |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁當前第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁
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
μ
A of power supply
current and features a standby mode which requires only 10
μ
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 +5V analog supply
(AV
DD
), and the AD7714-3, which is specified for operation
from a nominal +3.3V analog supply. Both versions can be
operated with a digital supply (DV
DD
) voltage of either +3.3V
or +5V. AD7714Y grade parts operate with a nominal AV
DD
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 +20mV and 0 V to +2.5V. 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
+2.5V. With a reference voltage of +1.25V, the input ranges
are from 0 mV to +10 mV to 0 V to +1.25V 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 –3dB frequency and its out-
put rate can be programmed via the filter high and filter low
registers. With a master clock frequency of 2.4576MHz, the
programmable range for this first notch frequency and output
rate is from 4.8Hz to 1.01 kHz giving a programmable range
for the –3dB frequency of 1.26 Hz to 265Hz.
The basic connection diagram for the part is shown in Figure 2.
This shows both the AV
DD
and DV
DD
pins of the AD7714 being
driven from the analog +3V or +5V supply. Some applications
will have AV
DD
and DV
DD
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
DV
DD
SYNC
RESET
DRDY
CS
MCLK OUT
POL
DIN
DOUT
AIN1
AIN2
AGND
AIN6
AIN3
AIN4
AIN5
REF IN(+)
STANDBY
REF IN(–)
AV
DD
BUFFER
AD7714
0.1
m
F
0.1
m
F
10
m
F
ANALOG
GROUND
DIFFERENTIAL
ANALOG INPUT 3
DIFFERENTIAL
ANALOG INPUT 2
DIFFERENTIAL
ANALOG INPUT 1
DIGITAL
GROUND
0.1
m
F
10
m
F
V
OUT
V
IN
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
相關PDF資料 |
PDF描述 |
|---|---|
| AD7714ARS-3 | 3 V/5 V, CMOS, 500 uA Signal Conditioning ADC |
| AD7714ARS-5 | 3 V/5 V, CMOS, 500 uA Signal Conditioning ADC |
| AD7714ACHIPS-3 | 3 V/5 V, CMOS, 500 uA Signal Conditioning ADC |
| AD7714ACHIPS-5 | 3 V/5 V, CMOS, 500 uA Signal Conditioning ADC |
| AD7714YN | 3 V/5 V, CMOS, 500 uA Signal Conditioning ADC |
相關代理商/技術參數 |
參數描述 |
|---|---|
| AD7714ACHIPS-3 | 制造商:AD 制造商全稱:Analog Devices 功能描述:3 V/5 V, CMOS, 500 uA Signal Conditioning ADC |
| AD7714ACHIPS-5 | 制造商:AD 制造商全稱:Analog Devices 功能描述:3 V/5 V, CMOS, 500 uA Signal Conditioning ADC |
| AD7714AN-3 | 制造商:Rochester Electronics LLC 功能描述:24-BIT SIGMA DELTA A/D IC - Bulk 制造商:Analog Devices 功能描述: |
| AD7714AN5 | 制造商:ANA 功能描述:24 BIT, 1KSPS, DIP 24 |
發布緊急采購，3分鐘左右您將得到回復。