Datasheet

LM49370
www.ti.com SNAS356D –FEBRUARY 2007–REVISED MARCH 2012
ADC_1 CONFIGURATION REGISTER
This register is used to control the LM49370's audio ADC.
Table 12. ADC_1 (0x06h)
Bits Field Description
0 MIC_SELECT If set the microphone preamp output is added to the ADC input signal.
1 CPI_SELECT If set the cell phone input is added to the ADC input signal.
2 LEFT_SELECT If set the left stereo bus is added to the ADC input signal.
3 RIGHT_SELECT If set the right stereo bus is added to the ADC input signal.
5:4 ADC_SAMPLE This programs the closest expected sample rate of the mono ADC, which is a variable required by the AGC
_RATE algorithm whenever the AGC is in use. This does not set the sample rate of the mono ADC.
ADC_SAMPLE_RATE Sample Rate
00
2
8 kHz
01
2
12 kHz
10
2
16 kHz
11
2
24 kHz
7:6 HPF_MODE This sets the HPF of the ADC
HPF-MODE HPF Response
00
2
No HPF
F
S
= 8 kHz, −0.5 dB @ 300 Hz, Notch @ 55 Hz
01
2
F
S
= 12 kHz, −0.5 dB @ 450 Hz, Notch @ 82 Hz
F
S
= 16 kHz, −0.5 dB @ 600 Hz, Notch @ 110 Hz
F
S
= 8 kHz, −0.5 dB @ 150 Hz, Notch @ 27 Hz
10
2
F
S
= 12 kHz, −0.5 dB @ 225 Hz, Notch @ 41 Hz
F
S
= 16 kHz, −0.5 dB @ 300 Hz, Notch @ 55 Hz
11
2
No HPF
ADC_2 CONFIGURATION REGISTER
This register is used to control the LM49370's audio ADC.
Table 13. ADC_2 (0x07h)
Bit Field Description
s
0 ADC_MODE This sets the oversampling ratio of the ADC
MODE ADC OSR
0 125fs
1 128fs
1 ADC_MUTE If set, the analog inputs to the ADC are muted.
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