LM49370RL/NOPB National Semiconductor, LM49370RL/NOPB Datasheet - Page 38

• Manufacturer Part Number: LM49370RL/NOPB
• Description: IC AUDIO SUBSYSTEM 1.2W 49USMDXT
• Manufacturer: National Semiconductor
• Series: Boomer®, PowerWise®r
• Type: Class Dr

Specifications of LM49370RL/NOPB

• Output Type: 1-Channel (Mono) with Mono and Stereo Headphones
• Max Output Power X Channels @ Load: 1.2W x 1 @ 8 Ohm; 52mW x 2 @ 16 Ohm
• Voltage - Supply: 2.5 V ~ 5.5 V
• Features: 3D, Depop, I²C, I²S, Microphone, Mute, PCM, Shutdown, SPI, Standby, Volume Control
• Mounting Type: Surface Mount
• Package / Case: 49-MicroSMDxt
• Dc: 07+
• For Use With: LM49370RLEVAL - BOARD EVALUATION LM49370RL
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM49370RLTR

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Bits
Bits
3:0
4:0
12.18 SIDETONE ATTENUATION REGISTER
This register is used to control the analog sidetone attenuation. (Note 21)
Note 21: An active SIDETONE path to an audio output may result in the microphone DC blocking caps causing audio pops under the following situations:
1) Switching between internal and external microphone operation while in chip modes '10' or '11'.
2) Toggling in and out of powerdown/standby modes.
3) Toggling between chip modes '10' and '11' whenever external microphone operation is selected.
4) The insertion/removal of a headset while in chip modes '10' or '11' whenever external microphone operation is selected.
To avoid potential pop noises, it is recommended to set SIDETONE_ATTEN to '0000' until DC points have stabilized whenever the SIDETONE path is used.
12.19 CP_INPUT CONFIGURATION REGISTER
This register is used to control the differential cell phone input.
5
SIDETONE_
CPI_LEVEL
CPI_MUTE
ATTEN
Field
Field
This programs the attenuation applied to the microphone preamp output to produce a sidetone signal.
This programs the gain/attenuation applied to the cell phone input.
If set, the CPI input is muted at source.
SIDETONE_ATTEN
00100 to 11100
0101
1011
CPI_LEVEL
TABLE 20. SIDETONE (0x0Dh)
TABLE 21. CP_INPUT (0x0Eh)
00000
00001
00010
00011
11101
11110
11111
0000
0001
0010
0011
0100
2
2
to 1010
to 1111
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
38
Description
Description
−28.5 dB to +7.5 dB
−18 dB to −3 dB
Attenuation
−34.5 dB
−31.5 dB
+10.5 dB
−30 dB
−27 dB
−24 dB
−21 dB
−33 dB
−30 dB
+12 dB
+9 dB
Level
0 dB
-Inf