MAX9853 Maxim Integrated Products, MAX9853 Datasheet - Page 53

• Manufacturer Part Number: MAX9853
• Description: (MAX9851 / MAX9853) Stereo Audio CODECs
• Manufacturer: Maxim Integrated Products

PGAML/PGAMR configures the programmable-gain
adjustment setting for the microphone left/microphone
right input. Code 0x00 is maximum gain while 0x1F is
maximum attenuation. Table 27 lists the gain setting for
each code.
1 = Mute all microphone inputs.
0 = Mute disabled.
1 = External microphone inputs.
0 = Internal microphone inputs.
Table 27. Microphone Input Gain Control Settings
Table 28. Microphone Control Bit Settings
Stereo Audio CODECs with Microphone, DirectDrive
REG
0x12
Programmable-Gain Adjustment for Microphone
Headphones, Speaker Amplifiers, or Line Outputs
PGAML/PGAMR
0x0A
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
B7
______________________________________________________________________________________
External Microphone Mode (MEXT)
0
Sources (PGAML/PGAMR)
Microphone Mute (MMIC)
B6
0
SETTING (dB)
+20
+19
+18
+17
+16
+15
+14
+13
+12
+11
+10
B5
0
B4
0
1 = Additional +20dB of gain applied to microphone
inputs by the preamplifier
0 = 0dB of gain applied by the microphone preamplifier
Preamplifier gain adds to the gain set by PGAML/
PGAMR. See the Microphone Amplifiers section.
1 = Internal bias resistors for EXTMICBIASL and
EXTMICBIASR connected.
0 = Internal bias resistors disconnected.
1 = 470Ω.
0 = 2.2kΩ.
Select 2.2kΩ when using electret or amplified micro-
phones. Select 470Ω when using an external RC filter
near the headset jack.
Microphone Bias Output Impedance Select (RBIAS)
Microphone Preamplifier Enable (PALEN/PAREN)
PGAML/PGAMR
0x14–0x1F
MMIC
Microphone Control Register (0x12)
B3
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
0x12
0x13
MEXT
B2
Resistor Bias Enable (RBEN)
RBEN
SETTING (dB)
B1
+9
+8
+7
+6
+5
+4
+3
+2
+1
+0
RBIAS
B0
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