Datasheet
LT1124/LT1125
12
11245fe
PERFORMANCE COMPARISON
TYPICAL APPLICATIONS
–
+
OUTPUT
1124/25 TA03
365
1%
INPUT
15k
5%
340k
1%
20k
TRIM
15V
1/2 LT1124
–15V
RN60C FILM RESISTORS
THE HIGH GAIN AND WIDE BANDWIDTH OF THE LT1124/LT1125, IS USEFUL IN LOW
FREQUENCY HIGH CLOSED-LOOP GAIN AMPLIFIER APPLICATIONS. A TYPICAL
PRECISION OP AMP MAY HAVE AN OPEN-LOOP GAIN OF ONE MILLION WITH 500kHz
BANDWIDTH. AS THE GAIN ERROR PLOT SHOWS, THIS DEVICE IS CAPABLE OF 0.1%
AMPLIFYING ACCURACY UP TO 0.3Hz ONLY. EVEN INSTRUMENTATION RANGE
SIGNALS CAN VARY AT A FASTER RATE. THE LT1124/LT1125 “GAIN PRECISION —
BANDWIDTH PRODUCT” IS 75 TIMES HIGHER, AS SHOWN.
FREQUENCY (Hz)
GAIN ERROR (PERCENT)
0.01
0.1
1.0
0.1 10 100
1124/25 TA04
0.001
1
GAIN ERROR =
CLOSED-LOOP GAIN
OPEN-LOOP GAIN
TYPICAL
PRECISION
OP AMP
LT1124/LT1125
Gain 1000 Amplifi er with 0.01% Accuracy, DC to 1Hz Gain Error vs Frequency Closed-Loop Gain = 1000
Table 2 summarizes the performance of the LT1124/
LT1125 compared to the low cost grades of alternate
approaches.
The comparison shows how the specs of the LT1124/
LT1125 not only stand up to the industry standard OP-27,
but in most cases are superior. Normally dual and quad
performance is degraded when compared to singles, for
the LT1124/LT1125 this is not the case.
Table 2. Guaranteed Performance, V
S
= ±15V, T
A
= 25°C, Low Cost Devices
PARAMETER/UNITS
LT1124CN8
LT1125CN OP-27 GP OP-270 GP OP-470 GP UNITS
Voltage Noise, 1kHz 4.2
100% Tested
4.5
Sample Tested
–
No Limit
5.0
Sample Tested
nV/√Hz
Slew Rate 2.7
100% Tested
1.7
Not Tested
1.7 1.4 V/µs
Gain-Bandwidth Product 8.0
100% Tested
5.0
Not Tested
–
No Limit
–
No Limit
MHz
Offset Voltage LT1124
LT1125
100
140
100
–
250
–
–
1000
µV
µV
Offset Current LT1124
LT1125
20
30
75
–
20
–
–
30
nA
nA
Bias Current 30 80 60 60 nA
Supply Current/Amp 2.75 5.67 3.25 2.75 mA
Voltage Gain, R
L
= 2k 1.5 0.7 0.35 0.4 V/µV
Common Mode Rejection Ratio 106 100 90 100 dB
Power Supply Rejection Ratio 110 94 104 105 dB
SO-8 Package Yes – LT1124 Yes No –