XTR101.PDF

(195 KB) Pobierz
®
XTR101
Precision, Low Drift
4-20mA TWO-WIRE TRANSMITTER
FEATURES
q
INSTRUMENTATION AMPLIFIER INPUT
Low Offset Voltage, 30
µ
V max
Low Voltage Drift, 0.75
µ
V/
°
C max
Low Nonlinearity, 0.01% max
q
TRUE TWO-WIRE OPERATION
Power and Signal on One Wire Pair
Current Mode Signal Transmission
High Noise Immunity
q
DUAL MATCHED CURRENT SOURCES
q
WIDE SUPPLY RANGE: 11.6V to 40V
q
–40
°
C to +85
°
C SPECIFICATION RANGE
q
SMALL 14-PIN DIP PACKAGE, CERAMIC
AND PLASTIC
APPLICATIONS
q
INDUSTRIAL PROCESS CONTROL
Pressure Transmitters
Temperature Transmitters
Millivolt Transmitters
q
RESISTANCE BRIDGE INPUTS
q
THERMOCOUPLE INPUTS
q
RTD INPUTS
q
CURRENT SHUNT (mV) INPUTS
q
PRECISION DUAL CURRENT SOURCES
q
AUTOMATED MANUFACTURING
q
POWER/PLANT ENERGY SYSTEM
MONITORING
DESCRIPTION
The XTR101 is a microcircuit, 4-20mA, two-wire
transmitter containing a high accuracy instrumenta-
tion amplifier (IA), a voltage-controlled output current
source, and dual-matched precision current reference.
This combination is ideally suited for remote signal
conditioning of a wide variety of transducers such as
thermocouples, RTDs, thermistors, and strain gauge
bridges. State-of-the-art design and laser-trimming,
wide temperature range operation and small size make
it very suitable for industrial process control applica-
tions. In addition, the optional external transistor al-
lows even higher precision.
The two-wire transmitter allows signal and power to
be supplied on a single wire-pair by modulating the
power supply current with the input signal source. The
transmitter is immune to voltage drops from long runs
and noise from motors, relays, actuators, switches,
transformers, and industrial equipment. It can be used
by OEMs producing transmitter modules or by data
acquisition system manufacturers.
I
REF1
I
REF2
10
e
1
3
–
11
+V
CC
8
Optional
External
Transistor
5
(1)
Span
6
XTR101
12
B
e
2
4
+
(1)
13
1
2
14 7
9
E
I
OUT
Optional
Offset Null
NOTE: (1) Pins 12 and 13 are used for optional BW control.
International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111
Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
©
1986 Burr-Brown Corporation
PDS-627G
Printed in U.S.A. October, 1993
SPECIFICATIONS
ELECTRICAL
At T
A
= +25°C, +V
CC
= 24VDC, and R
L
= 100Ω with external transistor connected, unless otherwise noted
XTR101AG
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
XTR101BG
TYP
MAX
MIN
XTR101AP
TYP
MAX
MIN
XTR101AU
TYP
MAX
UNITS
OUTPUT AND LOAD CHARACTERISTICS
Current
Current Limit
Offset Current Error
vs Temperature
Full Scale Output Current Error
Power Supply Voltage
Load Resistance
SPAN
Output Current Equation
Span Equation
vs Temperature
Untrimmed Error
(2)
Nonlinearity
Hysteresis
Dead Band
INPUT CHARACTERISTICS
Impedance: Differential
Common-Mode
Voltage Range, Full Scale
Offset Voltage
vs Temperature
Power Supply Rejection
Bias Current
vs Temperature
Offset Current
vs Temperature
Common-Mode Rejection
(4)
Common-Mode Range
CURRENT SOURCES
Magnitude
Accuracy
Linear Operating Region
Derated Performance
4
3.8
28
±3.9
±10.5
±20
20
22
38
±10
±20
±40
±40
600
1400
T
T
T
±2.5
±8
±15
T
T
T
T
±6
±15
±30
T
T
T
i
O
= 4mA + [0.016Ω + (40/R
S
)] (e
2
– e
1
)
S = [0.016Ω + (40/R
S
)]
T
T
T
T
T
T
T
T
T
T
T
T
T
T
1
±60
±1.5
150
1
±30
0.3
T
6
1
V
CC
= 24V,
V
PIN 8
– V
PIN 10
,
11
= 19V
R
2
= 5kΩ, Fig. 5
T
T
T
±20
±0.35
T
T
T
T
T
T
T
±30
±0.75
T
T
±20
T
T
T
T
T
T
T
T
122
T
T
T
T
T
T
T
T
±100
T
T
T
T
T
T
T
T
T
T
T
T
122
T
T
T
T
T
T
T
31
±8.5
±10.5
±30
T
T
T
T
±19
±20
±60
T
600
1400
T
T
31
±8.5
T
±30
T
T
T
T
±19
±60
T
T
T
mA
mA
mA
µA
ppm, FS/°C
µA
VDC
Ω
Ω
I
OS
, I
O
= 4mA
∆I
OS
/∆T
Full Scale = 20mA
V
CC
, Pins 7 and 8,
+11.6
Compliance
(1)
At V
CC
= +24V, I
O
= 20mA
At V
CC
= +40V, I
O
= 20mA
R
S
in
Ω,
e
1
and e
2
in V
R
S
in
Ω
Excluding TCR of R
S
ε
SPAN
ε
NONLINEARITY
–5
±30
–2.5
0
0
0.4 || 3
10 || 3
±100
0
0.01
T
T
T
T
T
T
T
T
T
T
T
T
T
T
A/V
ppm/°C
%
%
%
%
GΩ || pF
GΩ || pF
V
µV
µV/°C
dB
nA
nA/°C
nA
nA/°C
dB
V
mA
∆e
= (e
2
– e
1
)
(3)
V
OS
∆V
OS
/∆T
∆V
CC
/PSRR = V
OS
Error
I
B
∆I
B
/∆T
I
OSI
∆I
OSI
/∆T
DC
e
1
and e
2
with Respect
to Pin 7
0
±30
±0.75
125
60
0.30
10
0.1
100
T
±100
T
T
T
T
T
110
T
T
110
90
4
T
vs Temperature
vs V
CC
vs Time
Compliance Voltage
Ratio Match
Accuracy
vs Tempeature
vs V
CC
vs Time
Output Impedance
TEMPERATURE RANGE
Specification
Operating
Storage
±0.06
±50
±3
±8
0
±0.014
±10
±1
20
±0.17
±80
±0.025
±30
T
T
T
±0.009
T
T
T
±0.075
±50
±0.2
T
T
T
T
±0.031
T
T
15
±0.37
T
±0.2
T
T
T
T
±0.031
T
T
15
±0.37
T
With Respect to Pin 7
Tracking
(1 – I
REF1
/I
REF2
)
X
100%
V
CC
– 3.5
T
±0.04
10
T
±0.088
T
T
±0.088
T
%
ppm/°C
ppm/V
ppm/month
V
%
ppm/°C
ppm/V
ppm/month
MΩ
°C
°C
°C
±0.06
±15
10
–40
–55
–55
T
+85
+125
+165
T
T
T
T
T
T
T
–40
–40
–55
T
+85
+85
+125
T
–40
–55
T
+85
+125
T
Same as XTR101AG.
NOTES: (1) See Typical Performance Curves. (2) Span error shown is untrimmed and may be adjusted to zero. (3) e
1
and e
2
are signals on the –In and +In terminals
with respect to the output, pin 7. While the maximum permissible
∆e
is 1V, it is primarily intended for much lower input signal levels, e.g., 10mV or 50mV full scale
for the XTR101A and XTR101B grades respectively. 2mV FS is also possible with the B grade, but accuracy will degrade due to possible errors in the low value
span resistance and very high amplification of offset, drift, and noise. (4) Offset voltage is trimmed with the application of a 5V common-mode voltage. Thus the
associated common-mode error is removed. See Application Information section.
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
®
XTR101
2
PIN CONFIGURATION
Top View
DIP
Top View
SOIC
Zero Adjust
Zero Adjust
–In
+In
Span
Span
Out
1
2
3
4
5
6
7
DIP
14
13
12
11
10
9
8
Zero Adjust
Bandwidth
B Control
I
REF2
I
REF1
E
+V
CC
Zero Adjust
Zero Adjust
–In
+In
Span
Span
Out
NC
1
2
3
4
5
6
7
8
SOL-16
Surface-Mount
16
15
14
13
12
11
10
9
Zero Adjust
Bandwidth
B Control
I
REF2
I
REF1
E
+V
CC
NC
ABSOLUTE MAXIMUM RATINGS
Power Supply, +V
CC
........................................................................... 40V
Input Voltage, e
1
or e
2
........................................................
≥V
OUT
,
≤+V
CC
Storage Temperature Range, Ceramic ........................ –55°C to +165°C
Plastic ............. –55°C to +125°C
Lead Temperature (soldering 10s) G, P ...................................... +300°C
(wave soldering, 3s) U .......................... +260°C
Output Short-Circuit Duration ........................... Continuous +V
CC
to I
OUT
Junction Temperature ................................................................... +165°C
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degrada-
tion to complete device failure. Precision integrated circuits
may be more susceptible to damage because very small
parametric changes could cause the device not to meet its
published specifications.
PACKAGE/ORDERING INFORMATION
PRODUCT
XTR101AG
XTR101BG
XTR101AP
XTR101AU
PACKAGE
14-Pin Ceramic DIP
14-Pin Ceramic DIP
14-Pin Plastic DIP
16-Lead SOIC
PACKAGE
DRAWING
NUMBER
(1)
169
169
010
211
TEMPERATURE
RANGE
–40°C
–40°C
–40°C
–40°C
to
to
to
to
+85°C
+85°C
+85°C
+85°C
NOTE: (1) For detailed drawing and dimension table, please see end of data
sheet, or Appendix C of Burr-Brown IC Data Book.
®
3
XTR101
TYPICAL PERFORMANCE CURVES
At T
A
= +25°C, +V
CC
= 24VDC, unless otherwise noted.
SPAN vs FREQUENCY
80
STEP RESPONSE
25
Transconductance (20 Log m )
R
S
= 25Ω
60
R
S
= 100Ω
R
S
= 400Ω
40
R
S
= 2kΩ
20
R
S
=
∞
C
C
= 0
20
Output Current (mA)
R
S
=
∞
R
S
= 25Ω
∆e
IN
Full Scale (V)
0.04
0.4
CMR (dB)
0 to 800mV and
0 to 8kΩ scale
∆e
IN
Full Scale (V)
Power Supply Rejection (dB)
Bandwidth (Hz)
Ω
0
100
15
10
5
0
1k
10k
Frequency (Hz)
100k
1M
0
200
400
600
800
1000
Time (µs)
FULL SCALE INPUT VOLTAGE vs R
S
R
S
(kΩ)
0
0.08
2
4
6
8
0.8
120
100
COMMON-MODE REJECTION vs FREQUENCY
0.06
0.6
80
60
40
20
0.02
0 to 80mV (low level signals)
and 0 to 400Ω scale
0
0
100
200
R
S
(Ω)
300
0.2
0
400
0
0.1
1
10
100
Frequency (Hz)
1k
10k
100k
POWER SUPPLY REJECTION vs FREQUENCY
140
120
100
80
60
40
20
0
0.1
BANDWIDTH vs PHASE COMPENSATION
100k
10k
1k
R
S
= 100Ω
100
R
S
= 25Ω
10
1
0.1
R
S
= 400Ω
R
S
=
∞
10
100
1k
10k
100k
1M
10M
1
10
100
1k
10k
100k
1M
Frequency (Hz)
Bandwidth Control, C
C
(pF)
®
XTR101
4
TYPICAL PERFORMANCE CURVES
(CONT)
At T
A
= +25°C, +V
CC
= 24VDC, unless otherwise noted.
INPUT VOLTAGE NOISE DENSITY vs FREQUENCY
60
6
INPUT CURRENT NOISE DENSITY vs FREQUENCY
Input Noise Voltage (nV/ Hz )
Input Noise Current (pA/ Hz )
1
10
100
1k
10k
100k
50
40
30
20
10
0
Frequency (Hz)
5
4
3
2
1
0
1
10
100
1k
10k
100k
Frequency (Hz)
OUTPUT CURRENT NOISE DENSITY vs FREQUENCY
6
Output Noise Current (nA/ Hz )
5
4
3
2
1
0
1
10
100
1k
10k
100k
Frequency (Hz)
THEORY OF OPERATION
A simplified schematic of the XTR101 is shown in Figure 1.
Basically the amplifiers, A
1
and A
2
, act as a single power
supply instrumentation amplifier controlling a current source,
A
3
and Q
1
. Operation is determined by an internal feedback
loop. e
1
applied to pin 3 will also appear at pin 5 and
similarly e
2
will appear at pin 6. Therefore the current in R
S
,
the span setting resistor, will be I
S
= (e
2
– e
1
)/R
S
= e
IN
/R
S
.
This current combines with the current, I
3
, to form I
1
. The
circuit is configured such that I
2
is 19 times I
1
. From this
point the derivation of the transfer function is straightfor-
ward but lengthy. The result is shown in Figure 1.
Examination of the transfer function shows that I
O
has a
lower range-limit of 4mA when e
IN
= e
2
– e
1
= 0V. This 4mA
is composed of 2mA quiescent current exiting pin 7 plus
2mA from the current sources. The upper range limit of I
O
is
set to 20mA by the proper selection of R
S
based on the upper
range limit of e
IN
. Specifically R
S
is chosen for a 16mA
output current span for the given full scale input voltage
span; i.e., (0.016 + 40/R
S
)(e
IN
full scale) = 16mA. Note that
Ω
5
since I
O
is unipolar e
2
must be kept larger than e
1
; i.e., e
2
≥
e
1
or e
IN
≥
0. Also note that in order not to exceed the output
upper range limit of 20mA, e
IN
must be kept less than 1V
when R
S
=
∞
and proportionately less as R
S
is reduced.
INSTALLATION AND
OPERATING INSTRUCTIONS
BASIC CONNECTION
The basic connection of the XTR101 is shown in Figure 1.
A difference voltage applied between input pins 3 and 4 will
cause a current of 4-20mA to circulate in the two-wire
output loop (through R
L
, V
PS
, and D
1
). For applications
requiring moderate accuracy, the XTR101 operates very
cost-effectively with just its internal drive transistor. For
more demanding applications (high accuracy in high gain)
an external NPN transistor can be added in parallel with the
internal one. This keeps the heat out of the XTR101 package
®
XTR101

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika:

Zgłoś jeśli naruszono regulamin