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