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LT1113 Datasheet, PDF (13/16 Pages) Linear Technology – Dual Low Noise, Precision, JFET Input Op Amps | |||
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LT1113
TYPICAL APPLICATI S
Accelerometer Amplifier with DC Servo
ACCELEROMETER
B & K MODEL 4381
OR EQUIVALENT
R1
100M
C1
1250pF
R2
18k
R3 C2
2k 2µF
6
7
5V TO 15V
2â 8
1/2 LT1113
5
1
1/2 LT1113
3+
4
â5V TO â15V
R4
20M
R5
20M
C3
2µF
R4C2 = R5C3 > R1 (1 + R2/R3) C1
OUTPUT = 0.8mV/pC* = 8.0mV/g**
DC OUTPUT ⤠2.7mV
OUTPUT NOISE = 6nV/âHz AT 1kHz
*PICOCOULOMBS
**g = EARTHâS GRAVITATIONAL CONSTANT
OUTPUT
1113 ⢠TA03
Paralleling Amplifiers to Reduce Voltage Noise
3+
A1
1
1k
1/2 LT1113
2â
51â¦
1k
10k
3+
A2
1
1k
1/2 LT1113
2â
51â¦
1k
15V
6â 8
7
1/2 LT1113
5+
4
OUTPUT
15V
â15V
5+ 8
An
7
1k
1/2 LT1113
6â
4
1. ASSUME VOLTAGE NOISE OF LT1113 AND 51⦠SOURCE RESISTOR = 4.6nV/âHz
51â¦
â15V
1k
2. GAIN WITH n LT1113s IN PARALLEL = n ⢠200
3. OUTPUT NOISE = ân ⢠200 ⢠4.6nV/âHz
4. INPUT REFERRED NOISE = OUTPUT NOISE = 4.6
n ⢠200 ân
nV/âHz
5. NOISE CURRENT AT INPUT INCREASES ân TIMES
6. IF n = 5, GAIN = 1000, BANDWIDTH = 1MHz, RMS NOISE, DC TO 1MHz = 9µV = 4µV
â5
1113 ⢠TA04
13
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