LT1167CS8#TR Linear Technology, LT1167CS8#TR Datasheet - Page 16

• Manufacturer Part Number: LT1167CS8#TR
• Description: IC AMP INSTR PROG PREC LP 8SOIC
• Manufacturer: Linear Technology

Specifications of LT1167CS8#TR

• Amplifier Type: Instrumentation
• Number Of Circuits: 1
• Slew Rate: 1.2 V/µs
• Gain Bandwidth Product: 1MHz
• Current - Input Bias: 80pA
• Voltage - Input Offset: 20µV
• Current - Supply: 900µA
• Current - Output / Channel: 27mA
• Voltage - Supply, Single/dual (±): 4.6 V ~ 36 V, ±2.3 V ~ 18 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Output Type: -
• -3db Bandwidth: -

LT1167
applicaTions inForMaTion
Table 1. “Roll Your Own” vs LT1167 Error Budget
ERROR SOURCE
Absolute Accuracy at T
Input Offset Voltage, µV
Output Offset Voltage, µV
Input Offset Current, nA
CMR, dB
Drift to 85°C
Gain Drift, ppm/°C
Input Offset Voltage Drift, µV/°C
Output Offset Voltage Drift, µV/°C
Resolution
Gain Nonlinearity, ppm of Full Scale
Typ 0.1Hz to 10Hz Voltage Noise, µV
G = 100, VS = ±15V
All errors are min/max and referred to input.
the LT1167 are input offset voltage and CMRR. Note that
for the discrete solution, the noise voltage specification is
multiplied by √2 which is the RMS sum of the uncorelated
noise of the two input amplifiers. Each of the amplifier er-
rors is referenced to a full-scale bridge differential voltage
of 20mV. The common mode range of the bridge is 5V. The
LT1114 data sheet provides offset voltage, offset voltage
drift and offset current specifications for the matched op
amp pairs used in the error-budget table. Even with an
excellent matched op amp like the LT1114, the discrete
solution’s total error is significantly higher than the LT1167’s
16
PRECISION BRIDGE TRANSDUCER
350
350
10V
350
350
A
= 25°C
P-P
499
R
G
LT1167C CIRCUIT CALCULATION
60µV/20mV
(300µV/100)/20mV
[(450pA)(350/2)Ω]/20mV
110dB→[(3.16ppm)(5V)]/20mV
(50ppm + 10ppm)(60°C)
[(0.4µV/°C)(60°C)]/20mV
[(6µV/°C)(60°C)]/100/20mV
15ppm
0.28µV
LT1167 MONOLITHIC
INSTRUMENTATION AMPLIFIER
G = 100, R
SUPPLY CURRENT = 1.3mA MAX
P-P
+
–
Figure 6. “Roll Your Own” vs LT1167
/20mV
G
LT1167C
= ±10ppm TC
REF
total error. The LT1167 has additional advantages over
the discrete design, including lower component cost and
smaller size.
Current Source
Figure 7 shows a simple, accurate, low power program-
mable current source. The differential voltage across
Pins 2 and 3 is mirrored across R
R
put current. The 50µA bias current flowing from Pin 5 is
buffered by the LT1464 JFET operational amplifier. This
G
is amplified and applied across R
“ROLL YOUR OWN”’ CIRCUIT
CALCULATION
100µV/20mV
[(60µV)(2)/100]/20mV
[(450pA)(350Ω)/2]/20mV
[(0.02% Match)(5V)]/20mV
Total Absolute Error
(100ppm/°C Track)(60°C)
[(1.6µV/°C)(60°C)]/20mV
[(1.1µV/°C)(2)(60°C)]/100/20mV
Total Drift Error
10ppm
(0.3µV
Total Resolution Error
Grand Total Error
P-P
202 **
)(√2)/20mV
+
–
–
+
LT1114A
LT1114A
1/4
1/4
** DISCRETE 1% RESISTOR, ±100ppm/°C TC
* 0.02% RESISTOR MATCH, 3ppm/°C TRACKING
“ROLL YOUR OWN” INST AMP, G = 100
100ppm TRACKING
SUPPLY CURRENT = 1.35mA FOR 3 AMPLIFIERS
10k**
10k**
10k*
10k*
LT1167C “ROLL YOUR OWN”
ERROR, ppm OF FULL SCALE
3000
3944
3600
1200
4980
8953
150
790
180
15
14
29
4
G
. The voltage across
X
–
+
LT1114A
, defining the out-
1/4
10k*
10k*
10866
16461
5000
5564
6000
4800
500
60
66
10
21
31
4
1167 F06
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