LM4931 Datasheet, PDF (24/50 Pages) National Semiconductor (TI) – Audio Subsystem with Mono High Efficiency Loudspeaker and Stereo Headphone Amplifiers

LM4931
SNAS251E – APRIL 2004 – REVISED MAY 2013
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Typical Performance Characteristics (continued)
MIC PreAmp + ADC PSRR vs Frequency
Top Trace = 36dB MIC Gain, Bottom Trace = 6dB MIC Gain,
AV_DD = 5V
+0
-5
-10
-15
-20
-25
-30
-35
-40
-45
-50
-55
-60
-65
-70
-75
-80
-85
-90
-95
-100
MIC PreAmp + ADC PSRR vs Frequency
Top Trace = 36dB MIC Gain, Bottom Trace = 6dB MIC Gain,
AV_DD = 3V
+0
-5
-10
-15
-20
-25
-30
-35
-40
-45
-50
-55
-60
-65
-70
-75
-80
-85
-90
-95
-100
200
400 600 800 1k
2k 3k 4k
200
400 600 800 1k
2k 3k 4k
300 500 700 900
300 500 700 900
FREQUENCY (Hz)
Figure 20.
FREQUENCY (Hz)
Figure 21.
Headphone Sense In Hysteresis Loop
(AV_DD = 3V)
3
Headphone Sense In Hysteresis Loop
(AV_DD = 5V)
5
2.5
4
2
3
1.5
2
1
0.5
1
0
0 0.5 1 1.5 2 2.5 3
HEADPHONE SENSE IN (V)
Figure 22.
I²S DAC Frequency Response
( Handsfree Output)
+1
-0
-1
-2
-3
-4
-5
-6
20 50 100 200 500 1k 2k 5k 10k 20k
FREQUENCY (Hz)
Figure 24.
0
0
1
2
3
4
5
HEADPHONE SENSE IN
(V)
Figure 23.
I²S DAC Frequency Response Zoom
(Handsfree Output)
+2
+1.5
+1
+0.5
+0
-0.5
-1
-1.5
-2
2k 4k 6k 8k 10k 12k 14k 16k 18k 20k
FREQUENCY (Hz)
Figure 25.
24
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