DataSheet.es    


PDF AD7794 Data sheet ( Hoja de datos )

Número de pieza AD7794
Descripción Low Power 24-Bit Sigma-Delta ADC
Fabricantes Analog Devices 
Logotipo Analog Devices Logotipo



Hay una vista previa y un enlace de descarga de AD7794 (archivo pdf) en la parte inferior de esta página.


Total 21 Páginas

No Preview Available ! AD7794 Hoja de datos, Descripción, Manual

Preliminary Technical Data
Low Power, 24-Bit Sigma-Delta ADC with In-
www.DataSheet4U.com
Amp and Embedded Reference (6 Channel)
AD7794
FEATURES
Six Differential Analog Inputs
Low Noise Programmable Gain Instrumentation-Amp
RMS noise: 80 nV (Gain = 64)
Bandgap Reference with 5 ppm/ C Drift typ
Power
Supply: 2.7 V to 5.25 V operation
Normal: 400 µA typ
Power-down: 1 µA max
Update Rate: 4 Hz to 500 Hz
Simultaneous 50 Hz/60 Hz Rejection
Internal Clock Oscillator
Reference Detect
Programmable Current Sources (10 µA/200 µA/1 mA)
On-Chip Bias Voltage Generator
100 nA Burnout Currents
Low Side Power Switch
Independent Interface Power Supply
24-Lead TSSOP Package
INTERFACE
3-wire serial
SPI®, QSPI™, MICROWIRE™, and DSP compatible
Schmitt trigger on SCLK
APPLICATIONS
Temperature measurement
Pressure measurement
Weigh scales
GENERAL DESCRIPTION
The AD7794 is a low power, complete analog front end for
low frequency measurement applications. It contains a low
noise 24-bit ∑-∆ ADC with six differential inputs. The on-chip
low noise instrumentation amplifier means that signals of small
amplitude can be interfaced directly to the ADC.
The device contains a precision low noise, low drift internal
reference for absolute measurements. An external reference can
also be used if ratiometric measurements are required. Other
on-chip features include programmable excitation current
sources and a bias voltage generator for temperature applica-
tions along with 100 nA burnout currents. For pressure and
weighscale applications, a low-side power switch is available to
power down the bridge between conversions to minimize the
power consumption of the system. The device can be operated
with the internal clock or, alternatively, an external clock can be
used if synchronizing several devices. The output data rate
from the part is software programmable and can be varied from
4 Hz to 500 Hz.
The part operates with a power supply from 2.7 V to 5.25 V. It
consumes a current of 450 uA maximum and is housed in a 24-
lead TSSOP package.
FUNCTIONAL BLOCK DIAGRAM
VBIAS
AIN1(+)
AIN1(-)
AIN2(+)
AIN2(-)
AIN3(+)
AIN3(-)
AIN5(+)/IOUT2
AIN5(-)/IOUT1
AIN6(+)/P1
AIN6(-)/P2
PSW
GND
GND AVDD
VDD
MUX
GND
VDD
AIN4(+)/REFIN2(+) REFIN1(+) AIN4(-)/REFIN2(-) REFIN1(-)
BANDGAP
REFERENCE
GND
IN-AMP
SIGMA DELTA
ADC
REFERENCE
DETECT
SERIAL
INTERFACE
AND
CONTROL
LOGIC
DOUT/RDY
DIN
SCLK
CS
TEMP
SENSOR
INTERNAL
CLOCK
AD7794
DVDD
CLK
REV.PrE
6/04.
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved.

1 page




AD7794 pdf
Preliminary Technical Data
AD7794www.DataSheet4U.com
Parameter
AD7794 (CHOP DISABLED)
Output Update Rate
No Missing Codes2
Resolution
Output Noise and Update Rates
Integral Nonlinearity
Offset Error3
Offset Error Drift vs. Temperature4
Full-Scale Error3, 5
Gain Drift vs. Temperature4
Power Supply Rejection
ANALOG INPUTS
Differential Input Voltage Ranges
Absolute AIN Voltage Limits2
Unbuffered Mode
Buffered Mode
In-Amp Enabled
Common Mode Voltage
Analog Input Current
Buffered Mode or In-Amp Enabled
Average Input Current2
Average Input Current Drift
Unbuffered Mode
Average Input Current
Average Input Current Drift
Normal Mode Rejection2
Internal Clock
@ 50 Hz, 60 Hz
@ 50 Hz
@ 60 Hz
External Clock
@ 50 Hz, 60 Hz
@ 50 Hz
@ 60 Hz
Common Mode Rejection
@DC
@ 50 Hz, 60 Hz2
@ 50 Hz, 60 Hz2
REFERENCE INPUT
Internal Reference Initial Accuracy
Internal Reference Drift
AD7794B
4
500
24
15.5
18.5
See Tables in ADC
Description
±15
±25
±200/Gain
±200/Gain
±10
±0.5
±3
80
±REFIN/Gain
GND – 30 mV
AVDD + 30 mV
GND + 100 mV
AVDD – 100 mV
GND + 100 mV
AVDD – 1.1
0.5
±200
±2
±400
±50
1
60
80
90
60
94
90
80
80
80
1.17 ±0.01%
5
15
Unit
Hz min nom
Hz max nom
Bits min
Bits p-p
Bits p-p
Test Conditions/Comments
Settling Time = 1/Output Update Rate
fADC ≤125 Hz
Gain = 128, 16.6 Hz Update Rate, VREF = 2.5 V
Gain = 1, 16.6 Hz Update Rate, VREF = 2.5 V
ppm of FSR max
ppm of FSR max
µV typ
nV/°C typ
µV typ
ppm/°C typ
ppm/°C typ
dB min
3.5 ppm of FSR typ. Gain = 1 to 32
5 ppm of FSR typ, Gain = 64 or 128
Without Calibration
Gain = 1 or 2
Gain = 4 to 128
100 dB typ, AIN = FS/2
V nom
REFIN = REFIN(+) – REFIN(–) or Internal Reference,
Gain = 1 to 128
V min
V max
V min
V max
V min
V max
V min
Gain = 1 or 2
Gain = 1 or 2
Gain = 4 to 128
Gain = 4 to 128
pA max
pA/°C typ
nA/V typ
pA/V/°C typ
nA max
Gain = 1 or 2
Input current varies with input voltage.
AIN6(+) / AIN6(-)
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
V min/max
ppm/°C typ
ppm/°C max
70 dB typ, 50 ± 1 Hz, 60 ± 1 Hz, FS[3:0] = 10106
90 dB typ, 50 ± 1 Hz, FS[3:0] = 10016
100 dB typ, 60 ± 1 Hz, FS[3:0] = 10006
70 dB typ, 50 ± 1 Hz, 60 ± 1 Hz, FS[3:0] = 10106
100 dB typ, 50 ± 1 Hz, FS[3:0] = 10016
100 dB typ, 60 ± 1 Hz, FS[3:0] = 10006
AIN = +FS/2
FS[3:0] = 10106
50 ± 1 Hz, 60 ± 1 Hz, FS[3:0] = 10106
50 ± 1 Hz (FS[3:0] = 10016), 60 ± 1 Hz (FS[3:0] =
10006)
REV.PrE 6/04 | Page 5

5 Page





AD7794 arduino
Preliminary Technical Data
ABSOLUTE MAXIMUM RATINGS
Table 3. (TA= 25°C, unless otherwise noted.)
Parameter
Rating
AVDD to GND
–0.3 V to +7 V
DVDD to GND
–0.3 V to +7 V
Analog Input Voltage to GND
–0.3 V to AVDD + 0.3 V
Reference Input Voltage to GND
–0.3 V to AVDD + 0.3 V
Digital Input Voltage to GND
–0.3 V to AVDD + 0.3 V
Digital Output Voltage to GND
–0.3 V toA VDD + 0.3 V
AIN/Digital Input Current
10 mA
Operating Temperature Range
–40°C to +105°C
Storage Temperature Range
–65°C to +150°C
Maximum Junction Temperature
150°C
TSSOP
θJA Thermal Impedance
97.9°C/W
θJC Thermal Impedance
14°C/W
Lead Temperature, Soldering
Vapor Phase (60 sec)
215°C
Infrared (15 sec)
220°C
AD7794www.DataSheet4U.com
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those listed in the operational sections
of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
REV.PrE 6/04 | Page 11

11 Page







PáginasTotal 21 Páginas
PDF Descargar[ Datasheet AD7794.PDF ]




Hoja de datos destacado

Número de piezaDescripciónFabricantes
AD77914-Bit 128 kSPS Complete Sampling ADCAnalog Devices
Analog Devices
AD779016-Bit Buffered Sigma-Delta ADCAnalog Devices
Analog Devices
AD7791Buffered 24-Bit Sigma-Delta ADCAnalog Devices
Analog Devices
AD7792(AD7792 / AD7793) 16/24-Bit Sigma-Delta ADCAnalog Devices
Analog Devices

Número de piezaDescripciónFabricantes
SLA6805M

High Voltage 3 phase Motor Driver IC.

Sanken
Sanken
SDC1742

12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.

Analog Devices
Analog Devices


DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares,
permitiéndote verlos en linea o descargarlos en PDF.


DataSheet.es    |   2020   |  Privacy Policy  |  Contacto  |  Buscar