Sensors & Field Transmitters Brochure

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TEXAS INSTRUMENTS w
Monitoring and maintaining process variables at the appropriate levels is extremely critical in
industrial auto ma tion and process control. A sensor in the industrial environment is either
continuously or periodically measuring vital parameters such as temperature, pressure, ow,
etc. The primary challenge of sensing in industrial environments is conditioning low signal
levels in the presence of high noise and high surge voltage.
This warrants for extremely low noise, low drift, precision programmable gain amplifi ers
and instrumentation amplifi ers with an appropriate common-mode voltage. The rate of change
of the measured signal is usually not very rapid and hence high-resolution precision delta-
sigma converters are widely used in industrial sensors. Low power consumption is another key
requirement for industrial sensors as many of them are powered off the traditional 4–20 mA
loop. Digital connectivity features such as PROFIBUS, IO-Link, and wireless connectivity are
increasing in popularity as they provide continuous monitoring, fault diagnostics and reduce
start up times, greatly improving productivity and effi ciency of the automation loop.
Texas Instruments (TI) has a broad portfolio of products catering to industrial sensing,
ranging from best-in-class precision amplifi ers and data converters to interface products,
power products and high-performance microprocessors. TI’s cutting-edge semiconductor
manufacturing processes provide industrial designers with products that meet the highest
standards and that are optimized for industrial environments and extended product life cycles.
Industrial Automation Solutions
Sensors and Field Transmitters
TI’s sensor solutions speed the design cycle with the
right devices, software, tools and support.
What’s inside:
Field Transmitter:
Temperature Sensor
Field Transmitter:
Pressure Sensor
Flowmeters:
Electromagnetic
Coriolis
Electronic Weigh Scale
www.ti.com/automation
Temperature sensors are used to measure temp-
erature and have a wide range of uses in industrial
and com mer cial applications. Temperature
measure ments are commonly made by using a
resistance temperature detector (RTD), thermistor
or thermocouple.
RTDs have wire winding or thin-fi lm serpentine
elements that exhibit changes in resistance with
changes in temperature. Thermistors, typically
made of ceramic or polymer material, also exhibit
signifi cant changes in resistance with changes
in temperature. Thermocouples consist of two
dissimilar metal wires welded together to form
two junctions. Temperature differences between
the junctions cause a thermoelectric potential (i.e.,
a voltage) between the two wires. Holding the
reference junction at a known temperature and
measuring this voltage permits the temperature
of the sensing junction to be deduced. A constant
and linear excitation source is a critical aspect
of RTD/thermistor sensing, while cold junction
compensation is the key to a good temperature
measurement with thermocouples.
With its high integration, excellent resolution
and accuracy, the ADS1248 offers a single-chip
solution to all of these types of temperature
measurements. The ADS1118 is a lower-cost
solution which has the basic core needed for
any temperature measurement and an extremely
accurate on-chip temperature sensor that is
perfect for accurate cold junction compensation.
www.ti.com/automation
Pressure sensors convert a physical value –
weight, tire pressure, level, force or fl ow – into a
differential signal in the range of millivolts per volt
and use metal thick-fi lm, ceramic thin-fi lm, or
piezoresistive technologies, to name a few. The
majority of designers use the cost-effective
piezosensors that can sense 25 mbar to 25 bar.
However, these sensors are very nonlinear and
temperature-dependent and have a large offset
and large offset drift. They also require attention
to electronic calibration and compensation.
TI’s PGA309 sensor conditioner is an ideal
choice in combination with low-cost piezoresistive
or ceramic thin-fi lm pressure sensors. It is a
complete signal conditioner for bridge sensors
with versatile features that enable linearization,
temperature compensation and digital calibration.
Features and Benefi ts
Bridge excitation and sensor signal
conditioning
Sensor error compensation: span, offset
and temperature drifts
• Sensor linearization circuitry
Digital calibration via one- or two-wire
serial interface
Low, time-stable total adjusted error
Field Transmitter: Pressure Sensor
Keypad
On/Off
LCD
Display
ADC
Integrated Solution
MCU
4-20mA
4-20
DAC
Power Management
Battery
Powered
Line
Powered
Loop
Powered
O
R
O
R
Battery
Current
Source
MUX
egrated So
AMP Isolation
Wireless
Antenna
RS-232/RS-485
PROFIBUS
IO-Link
LCD
Backlight
Filtering
-
+
Thermocouple
V
Filtering
RTD
or
Thermistor
V/I
HART
Field Transmitter: Temperature Sensor
Features and Benefi ts
Highly integrated solution
Dual matched-current DACs
– Low-drift internal reference
Low-noise PGA, temperature sensor,
burnout detection
24 bits, no missing codes, single-cycle
settling, up to 2 kSPS
• 50-/60-Hz rejection
+125ºC
+40ºC
T
Nonlinear
Bridge
Transducer
Pressure
Power Management
Battery
Powered
Line
Powered
Loop
Powered
O
R
O
R
Battery
Wireless
Antenna
Integrated Solution
Linearization
Circuit VREF
DAC
MUX AMP ADC
TMP
ADC
Cum Cubic Feet
MCU
4-20mA
RS-232/RS-485
PROFIBUS
IO-Link
DAC
HART
Isolation
www.ti.com/automation
Electronic weigh scales, which are found in many
industrial applications, use a load cell as the
primary transducer. Load-cell designs can be
distinguished according to the type of output
signal they generate – pneumatic, hydraulic or
electric. Strain-gauge load cells convert the load
acting on them into electrical signals in the range
of millivolts per volt. A major challenge in
designing weigh scales is that they must sample
multiple load cells while producing extremely low
input referred noise.
Another important factor is the analog circuitry’s
long-term stability with regard to offset drift and
gain. Here the accuracy of the amplifi ed input
signal, either single-ended or differential, must
be guaranteed over years of operation. Hence
the signal chain has to handle the small signals
accurately in the presence of noise in addition
to conditioning for offset, drift, temperature
dependency and other factors.
TI’s ADS1232 is designed as a highly integrated
delta-sigma ADC for low-level, high-precision
measurements, especially for weigh-scale
applications. The device consists of a low-drift,
low-noise instrumentation amplifi er (selectable
gain) and a high-order, chopper-stabilized
modulator followed by a digital fi lter in a
monolithic device. This is a single-chip solution
that can be directly interfaced as a front end to a
load-cell bridge output.
Features and Benefi ts
Complete front-end solution for weigh
scales
• Very low-noise PGA
Only 17-nV input-referred noise with gain
of 128
• 23.5 effective bits with gain of 1
Excellent 50-/60-Hz rejection:
100 dB (min)
Electronic Weigh Scale
Load Cell
Load Cell
Load Cell
Load Cell
LCD
Backlight
RS-232
RS-485
Ethernet
Filtering
ADC
AMP
Battery
Powered
Line
Powered
Power Management
O
R
AC
Adapter
AC Line
Plug
Integrated ADC
Solution MCU
VREF
Wireless
The electromagnetic fl owmeter consists of a
nonferromagnetic tube wrapped with a magnetic
coil. Electrodes in the tube’s inner isolated surface
are in contact with a conductive liquid that fl ows
through the tube. The coils around the pipe
generate a magnetic fi eld within the tube. The
magnetic fi eld inducts a voltage in the liquid that
is proportional to the speed of the liquid in the
tube. This voltage is measured via the electrodes.
Because the measured voltage is very low, precise
low-noise signal conditioning is required.
Coriolis fl owmeter is a popular fl owmeter
that directly measures mass fl ow rate. Applying a
strong magnetic fi eld to a pipe through which fl uid
is fl owing makes the pipe oscillate at a particular
resonant frequency. When the fl uid starts fl owing
through the pipe, it is subject to Coriolis force.
The oscillatory motion of the pipe superimposes
on the linear motion of the fl uid, exerting twisting
forces on the pipe. This twisting is due to Coriolis
acceleration acting in opposite directions on either
side of the pipe and to the fl uid’s resistance to
the vertical motion. Sensor electrodes placed on
both the inlet and outlet sides pick up the phase
difference caused by this motion. This phase shift
due to the twisting forces is a direct measurement
of mass fl ow rate.
Low-noise instrumentation amplifi ers followed
by precision ADCs is typical of the signal-chain
path. Precision DACs or PWM drivers are used to
excite the fi eld coils. Multiple-channel ADCs with
simultaneous sampling architectures make it
possible to take multiple measurements such as
temperature, phase, density, etc. at the same time.
TI’s ADS1274, which is a 24-bit, 4-channel,
simultaneous-sampling delta-sigma converter
with up to 144 kSPS, is the perfect front end for
owmeters requiring multiple measurements
(Coriolis). The ADS1259 is a high-linearity, low-
drift, 24-bit, delta-sigma converter commonly used
in electromagnetic fl owmeters.
Features and Benefi ts
Multiple channels and simultaneous
sampling for measuring multiple process
variables at the same time
Excellent AC and DC performance
Selectable operating modes: High speed,
high resolution, low power
Flowmeters: Electromagnetic/Coriolis
IO-Link
Processor
Processor
Power Management
ADC
ADC
ADC
Driver
The Magnetic-Inductive Flowmeter
Driver
The Coriolis Flowmeter
Isolation
PROFIBUS
RS-232/RS-485
Wireless
4-20mA
DAC
HART
Isolation
Line
Powered
Loop
Powered
O
R
IO-Link
PROFIBUS
RS-232/RS-485
Wireless
4-20mA
DAC
HART
Flow
Flow
I TEXAS INSTRUMENTS
SLYB177B
Important Notice: The products and services of Texas Instruments Incorporated and its subsidiaries described herein are sold subject to TI’s standard terms and conditions of sale. Customers
are advised to obtain the most current and complete information about TI products and services before placing orders. TI assumes no liability for applications assistance, customer’s applications
or product designs, software performance, or infringement of patents. The publication of information regarding any other company’s products or services does not constitute TI’s approval,
warranty or endorsement thereof.
The platform bar, C5000 and MSP430 are trademarks of Texas Instruments. ZigBee is a registered trademark of the ZigBee Alliance. All other trademarks are the property of their respective owners.
© 2011 Texas Instruments Incorporated
Function Features Part Number EVM/Demo
High-Precision
Instrumentation Amplifi er
Micropower (50 A), zero drift, low offset voltage (25 µV max), low offset drift 0.1 µV/°C),
rail-to-rail output instrumentation amplifi er
INA333
Complete Pressure/
Bridge Sensor Conditioner
Amplifi cation, bridge excitation, digital calibration (for span, offset and temperature drift),
linearization, temperature compensation
PGA309 PGA309EVM-USB
Single-Chip Temperature-
Measurement Front End
High integration, low-noise PGA, 24-bit ADC, internal reference, dual-current DACs, temperature
sensor, burnout detection
ADS1248 ADS1248EVM/
ADS1248EVM-PDK
Integrated Single-Chip
Temperature Measurement
Front End
High accuracy on-chip temp sensor for CJC.
World’s smallest 16-bit ADC as of 2011Q3.
Integrated PGA for better utilization of dynamic range. Low power.
ADS1118 ADS1118EVM
Weigh-Scale Front End High integration, 24-bit precision ADC, on-board PGA, temperature sensor ADS1232 ADS1232EVM
Flowmeter Signal
Acquisition
Quad-channel simultaneous sampling, 144 kSPS, 24-bit ADC ADS1274 ADS1274EVM/
ADS1274EVM-PDK
DAC 12-bit, single-channel, 80 µA, 1.8-V to 5.5-V DAC in SC-70 package, can be used to drive HART signal DAC7311 DAC7311EVM
Ultra-Low Power MCU Ultra-low power, industrial feature set, 5V tol. I/O, high-resolution timer, stand-by in LPM3: 1.1 µA MSP430F51x2 MSP-TS430RSB40
Ultra-Low Power MCU Ultra-low power, universal memory, ADC10, active mode: 107 µA/MHz at 8 MHz MSP430FR5739 MSP-EXP430FR5739
IO-Link MCU Ultra-low power, 32-KB Flash, 1-KB RAM, IO-Link stack V1.1 (TMG) MSP430F2274 MSP-FET430U38
Low-Power DSP Industry’s lowest-powered DSP, energy-effi cient FFT hardware accelerator,
standby mode <0.15 mW, active mode < 0.15 mW/MHz, dynamic voltage a frequency scaling
TMS320C5515 TMDXEVM5515
4–20-mA Transmitter Low Iq, Vregulator, Vref for sensor excitation, low span and non-linearity error XTR115 XTR115EVM
PROFIBUS 4-KV peak-isolated PROFIBUS transceiver with low bus capacitance and bus-pin ESD protection IS01176 ISO1176EVM
IO-Link PHY IO-Link device node PHY with overcurrent/overvoltage/overtemperature protection, small footprint
4 mm × 4 mm QFN-20 package, internal voltage regulator
SN65HVD101
RS-485 4-KV peak-isolated, 5-V, full-duplex RS-485 transceiver ISO3080 ISO485EVM
Wireless Transceiver 2.4-GHz 802.15.4/ZigBee® RF transceiver, excellent link budget (103 dBm), 400-m line of sight,
extended temperature (–40 to +125°C)
CC2520 CC2520DK
Linear Regulator -3-V to -36-V input, -200-mA, ultra-low noise, high PSRR, low-dropout linear regulator TPS7A3001 TPS7A30-49EVM-567
Linear Regulator 100-V input, 50-mA, single-output low-dropout linear regulator TPS7A4001 TPS7A4001EVM-709
Isolated Regulator 0.95-V to 6-V Input, 2-W isolated DC/DC converter with integrated FETs TPS55010 TPS55010EVM-009
Isolated Regulator 5-/12-/24-V input, 1-W isolated regulated DC/DC converter modules DCR01
DC/DC Converter 4.5- to 60-V input, 50-mA synchronous buck converter TPS54062 TPS54062EVM-695
DC/DC Converter 3.5- to 60-V input, 1.5-A DC/DC converter with light load effi ciency and low IqTPS54160 TPS54160EVM-230
Power Management
Industrial fi eld transmitters could be powered in
one of three ways: loop, line or battery.
Texas Instruments (TI) offers a complete line of
high-performance power management products
designed for industrial applications. The devices
shown are well-suited for powering sensors that
may require low noise and high effi ciency in both
line- and loop-powered (4–20 mA) topologies. Many
TI DC/DC converters feature current-mode control
with fast dynamic response and a pulse skipping
eco-mode with low quiescent current which
saves energy at light loads. Battery-powered
transmitters can be designed using TI’s low-power
Buck and Buck-Boost converters.
Processor and Connectivity
The MSP430™ MCU, with its integrated analog
peripherals, is the perfect platform for designers
looking to implement calibration routines,
compensation algorithms, etc. The computing
power and rich peripherals set accented by ultra-
low power consumption, makes the MSP430
MCU the universal choice for sensor design.
For fl owmeter applications which require more
signal processing than offered by a standard MCU,
the C5000™ platform of DSPs is the optimal
solution. The C5000 DSP has an FFT accelerator
core that enables computing FFTs in a matter
of seconds while drawing very little current. The
ultra-low-power architecture of the C5000 DSP
offers superior signal-processing power while still
being able to be powered off the 4–20-mA loop.
Traditional analog (4–20 mA) interface remains
the popular choice for industrial control and
sensor applications. The other popular protocols
include HART, PROFIBUS and IO-Link. TI’s IO-Link
interface products have integrated regulators
and diagnostic outputs. In addition, wireless
options based on IEEE 802.15.4 protocols are
becoming more prevalent. TI is committed to
provide solutions for both traditional and emerging
industrial interfaces.
www.ti.com/automation
Industrial Automation Solutions
Sensors and Field Transmitters portfolio at a glance