lm49370rl National Semiconductor Corporation, lm49370rl Datasheet - Page 30

• Manufacturer Part Number: lm49370rl
• Description: Audio Sub-system With An Ultra Low Emi, Spread Spectrum, Class D Loudspeaker Amplifier, A Dual-mode Stereo Headphone Amplifier, And A Dedicated Pcm Interface For Bluetooth Transceivers
• Manufacturer: National Semiconductor Corporation

www.national.com
Bits
5:4
7:6
12.10 ADC_1 CONFIGURATION REGISTER
This register is used to control the LM49370's audio ADC.
0
1
2
3
RIGHT_SELECT If set the right stereo bus is added to the ADC input signal.
ADC_SAMPLE_
LEFT_SELECT
MIC_SELECT
CPI_SELECT
HPF_MODE
RATE
Field
If set the microphone preamp output is added to the ADC input signal.
If set the cell phone input is added to the ADC input signal.
If set the left stereo bus is added to the ADC input signal.
This programs the closest expected sample rate of the mono ADC, which is a variable required by the
AGC algorithm whenever the AGC is in use. This does not set the sample rate of the mono ADC.
This sets the HPF of the ADC
ADC_SAMPLE_RATE
HPF-MODE
00
01
10
11
00
01
10
11
TABLE 12. ADC_1 (0x06h)
2
2
2
2
2
2
2
2
30
Description
F
F
F
F
F
F
S
S
S
S
S
S
= 8 kHz, −0.5 dB @ 300 Hz, Notch @ 55 Hz
= 12 kHz, −0.5 dB @ 450 Hz, Notch @ 82 Hz
= 16 kHz, −0.5 dB @ 600 Hz, Notch @ 110 Hz
= 8 kHz, −0.5 dB @ 150 Hz, Notch @ 27 Hz
= 12 kHz, −0.5 dB @ 225 Hz, Notch @ 41 Hz
= 16 kHz, −0.5 dB @ 300 Hz, Notch @ 55 Hz
HPF Response
Sample Rate
No HPF
No HPF
12 kHz
16 kHz
24 kHz
8 kHz