LT1028 Datasheet, PDF (15/20 Pages) Linear Technology – Ultra Low Noise Precision High Speed Op Amps

TYPICAL APPLICATI
Paralleling Amplifiers to Reduce Voltage Noise
+
A1
1.5k
LT1028
–
7.5Ω
470Ω
+
A2
1.5k
LT1028
–
7.5Ω
470Ω
+
An
1.5k
LT1028
–
7.5Ω
470Ω
4.7k
–
LT1028
+
OUTPUT
1.ASSUME VOLTAGE NOISE OF LT1028 AND 7.5 Ω SOURCE RESISTOR = 0.9nV/√Hz.
2.GAIN WITH n LT1028s IN PARALLEL = n × 200.
3.OUTPUT NOISE = √n × 200 × 0.9nV/√Hz.
4.INPUT REFERRED NOISE =
OUTnPU_×T20N0OISE=
0.9nV/ _√Hz.
√n
5.NOISE CURRENT AT INPUT INCREASES √n TIMES.
6.IF n = 5, GAIN = 1000, BANDWIDTH = 1MHz, RMS NOISE, DC TO 1MHz = ^2µV= 0.9 µV.
√5
1028/1128 TA03
Low Noise, Wide Bandwidth Instrumentation Amplifier
–INPUT
+
LT1028
300Ω
10k
–
820Ω
68pF
50Ω
10Ω
+INPUT
–
820Ω
LT1028
+
68pF
300Ω
GAIN = 1000, BANDWIDTH = 1MHz
INPUT REFERRED NOISE = 1.5nV/√Hz AT 1kHz
WIDEBAND NOISE –DC to 1MHz = 3µV_RMS
IF BW LIMITED TO DC TO 100kHz = 0.55µV_RMS
–
LT1028
+
10k
SINE
DRIVE
OUTPUT
1028/1128 TA08
LT1028/LT1128
Phono Preamplifier
10Ω
787Ω
15V
0.1µF
10k
2_– 7
100pF
6
LT1028
3₊
4
0.33µF
OUTPUT
47k
–15V
MAG PHONO
INPUT
ALL RESISTORS METAL FILM
1028/1128 TA06
Tape Head Amplifier
0.1µF
499Ω
31.6k
10Ω
2_–
6
LT1028
TAPE HEAD 3 ₊
INPUT
OUTPUT
ALL RESISTORS METAL FILM
1028/1128 TA07
Gyro Pick-Off Amplifier
GYRO TYPICAL–
NORTHROP CORP.
GR-F5AH7-5B
+
•
LT1028
OUTPUT TO SYNC
DEMODULATOR
–
1k
100Ω
1028/1128 TA09
15