ADC. AD7191 Datasheet

AD7191 Datasheet PDF


Part

AD7191

Description

Sigma-Delta ADC

Manufacture

Analog Devices

Page 20 Pages
Datasheet
Download AD7191 Datasheet


AD7191 Datasheet
Pin-Programmable, Ultralow Noise, 24-Bit,
Sigma-Delta ADC for Bridge Sensors
AD7191
FEATURES
GENERAL DESCRIPTION
Pin-programmable output rate
Output data rate: 10 Hz, 50 Hz, 60 Hz, 120 Hz
Pin-programmable PGA
Gain: 1, 8, 64, 128
Pin-programmable power-down and reset
RMS noise: 15 nV @ 10 Hz (gain = 128)
Up to 21.5 noise free bits (gain = 1)
Internal or external clock
Bridge power-down switch
Offset drift: 5 nV/°C
Gain drift: 1 ppm/°C
Specified drift over time
Simultaneous 50 Hz/60 Hz rejection
Internal temperature sensor
Power supply: 3 V to 5.25 V
Current: 4.35 mA
Temperature range: –40°C to +105°C
Package: 24-lead TSSOP
INTERFACE
2-wire serial
SPI, QSPI™, and MICROWIRE™ compatible
Schmitt trigger on SCLK
The AD7191 is a low noise, complete analog front end for high
precision measurement applications. It contains a low noise,
24-bit sigma-delta (Σ-Δ) ADC. The on-chip low noise gain
stage means that signals of small amplitude can be interfaced
directly to the ADC. It contains two differential analog inputs.
The part also includes a temperature sensor that can be used for
temperature compensation.
For ease-of-use, all the features of the AD7191 are controlled by
dedicated pins. The on-chip PGA has a gain of 1, 8, 64, or 128,
supporting a full-scale differential input of ±5 V, ±625 mV,
±78 mV, or ±39 mV. The output data rate can be programmed
to 10 Hz, 50 Hz, 60 Hz, or 120 Hz. Simultaneous 50 Hz and 60 Hz
rejection is obtained when the output data rate is set to 10 Hz
or 50 Hz; 60 Hz only rejection is obtained when the output data
rate is set to 60 Hz. The AD7191 can be operated with the
internal clock, or an external clock can be used.
The part operates with a power supply of 3 V to 5.25 V. It
consumes a current of 4.35 mA. It is available in a 24-lead
TSSOP package.
APPLICATIONS
Weigh scales
Strain gauge transducers
www.DPatraeSshsueeret4mU.ecaosmurement
Medical and scientific instrumentation
AVDD
FUNCTIONAL BLOCK DIAGRAM
AGND DVDD DGND REFIN(+) REFIN(–)
AIN1
AIN2
AIN3
AIN4
AD7191
MUX
PGA
Σ-Δ
ADC
SERIAL
INTERFACE
AND CONTROL
LOGIC
DOUT/RDY
SCLK
PDOWN
CHAN
CLKSEL
BPDSW
TEMPERATURE
SENSOR
CLOCK
CIRCUITRY
PGA2
PGA1
MCLK1 MCLK2
Figure 1.
ODR2 ODR1 TEMP
Rev. A
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.
Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2009 Analog Devices, Inc. All rights reserved.

AD7191 Datasheet
AD7191
TABLE OF CONTENTS
Features .............................................................................................. 1
Interface ............................................................................................. 1
Applications....................................................................................... 1
General Description ......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Timing Characteristics ................................................................ 6
Timing Diagram ........................................................................... 6
Absolute Maximum Ratings............................................................ 7
ESD Caution.................................................................................. 7
Pin Configuration and Function Descriptions............................. 8
Typical Performance Characteristics ........................................... 10
RMS Noise and Resolution Specifications .................................. 13
ADC Circuit Information.............................................................. 14
Overview...................................................................................... 14
Filter, Data Rate, and Settling Time ......................................... 14
REVISION HISTORY
5/09—Rev. 0 to Rev A
Changes to Gain Error Specification, Normal Mode
Rejection Specification..................................................................... 3
Changes to Table 3............................................................................ 7
5/09—Revision 0: Initial Version
www.DataSheet4U.com
Gain.............................................................................................. 15
Analog Input Channels.............................................................. 15
Temperature Sensor ................................................................... 16
Power-Down (PDOWN)........................................................... 16
Clock ............................................................................................ 16
Bipolar Configuration................................................................ 16
Data Output Coding .................................................................. 16
Bridge Power-Down Switch...................................................... 16
Reference ..................................................................................... 16
Digital Interface.......................................................................... 17
Grounding and Layout .............................................................. 17
Applications Information .............................................................. 19
Weigh Scales................................................................................ 19
EMI Recommendations............................................................. 19
Outline Dimensions ....................................................................... 20
Ordering Guide .......................................................................... 20
Rev. A | Page 2 of 20


Features Datasheet pdf Pin-Programmable, Ultralow Noise, 24-Bit , Sigma-Delta ADC for Bridge Sensors AD 7191 FEATURES Pin-programmable output r ate Output data rate: 10 Hz, 50 Hz, 60 Hz, 120 Hz Pin-programmable PGA Gain: 1 , 8, 64, 128 Pin-programmable power-dow n and reset RMS noise: 15 nV @ 10 Hz (g ain = 128) Up to 21.5 noise free bits ( gain = 1) Internal or external clock Br idge power-down switch Offset drift: 5 nV/°C Gain drift: 1 ppm/°C Specified drift over time Simultaneous 50 Hz/60 H z rejection Internal temperature sensor Power supply: 3 V to 5.25 V Current: 4 .35 mA Temperature range: –40°C to + 105°C Package: 24-lead TSSOP GENERAL DESCRIPTION The AD7191 is a low noise, complete analog front end for high prec ision measurement applications. It cont ains a low noise, 24-bit sigma-delta ( -Δ) ADC. The on-chip low noise gain s tage means that signals of small amplit ude can be interfaced directly to the A DC. It contains two differential analog inputs. The part also includes a temperature sensor that can be used f.
Keywords AD7191, datasheet, pdf, Analog Devices, Sigma-Delta, ADC, D7191, 7191, 191, AD719, AD71, AD7, stock, pinout, distributor, price, schematic, inventory, databook, Electronic, Components, Parameters, parts, cross reference, chip, Semiconductor, circuit, Electric, manual, substitute, Equivalent




@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site (Privacy Policy & Contact)