Datasheet

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