Datasheet

9
LT1115
1115fa
THD + Noise vs Frequency
(Figure 1)
Figure 1. Balanced Transformerless Microphone Preamp
FREQUENCY (Hz)
20
0.010
TOTAL HARMONIC DISTORTION + NOISE (%)
0.1
1
100
1k
20k
T
A
= 25
°
C
R
L
= 100kΩ
V
IN
= 10mV
RMS
V
OUT
= 2.92V
RMS
R
S
= 150Ω
LT1115 • TA04
–
+
1µF 35V
LOW ESR
1µF 35V
LOW ESR
R1
1k, 0.1%
R1
R2
1k, 0.1%
R2
R4
316k, 0.1%
R4
R3
316k, 0.1%
R3
INPUT
R
P
30k
1%
3
2
7
6
4
4.7µF
FILM
OUT
10k
1%
100
1%
18V
–18V
NOTE: MATCH RESISTOR PAIRS
TO ± 0.1%
LT1115
LT1115 • TA03
=
+
+
TYPICAL APPLICATIO S
U