LME49740_14 Datasheet, PDF (11/24 Pages) Texas Instruments – Quad High-Performance, High-Fidelity Audio Operational Amplifier

LME49740
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NOISE MEASUREMENT CIRCUIT
+V_CC -V_EE
+
47 PF
47 PF
+
V1
+
0.47 PF
390
LME49740
V2
-
15 nF 4.7 nF
+
39k
-
200k
16k
1k
390
SNAS377A – FEBRUARY 2007 – REVISED FEBRUARY 2008
0.47 PF
+
39k
-
99k
27 pF
1k
4.7 PF
+
V_O
AVERAGE RESPONDING
AC VOLT METER
99k
27 pF
RIAA PREAMP
35 dB, f = 1 kHz
FLAT AMP. 40 dB + 40 dB
A. Complete shielding is required to prevent induced pick up from external sources. Always check with oscilloscope for
power line noise.
Figure 24. Total Gain: 115 dB at f = 1 kHz
Input Referred Noise Voltage: e_n = V_O/560,000 (V)
RIAA Preamp Voltage Gain,
RIAA Deviation vs Frequency
V_IN = 10mV, A_V = 35.0dB, f = 1kHz
50
40
30
20
10
0
+1
0
-1
20
100
1k
10k 20k
FREQUENCY (Hz)
Figure 25.
Flat Amp Voltage Gain vs Frequency
V_O = 0dB, A_V = 80.0dB, f = 1kHz
90
80
70
60
50
40
30
20
10
100
1k
10k
100k
FREQUENCY (Hz)
Figure 26.
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