W681308DG Datasheet, PDF (45/64 Pages) Nuvotem Talema – W681308 USB Audio Controller from Nuvoton integrates fast 8051 Microcontroller Unit (MCU)

W681308
XXXX PRODUCT DESCRIPTION
Electret
Microphone
Rm
0 Ohm
Or ferrite
MIC_BIAS[2:0]
0x1488
W681308
MIC_RES[7:4]
0x1488
MCP
MCO
RGND
MIC_GAIN[7:4]
0x1489
R_INT1
R_INT2
MIC_GAIN[7:4]
0x1489
250 Ohm
Voltage Gain Mode
0x1489
MIC_MODE=‘000’
+
To ADC
-
VADC
= 1 + ^{RINT 1}
VMCP _'000'
RINT 2
Figure 9 Microphone Voltage Gain Mode
ƒ Current Gain Mode
For higher gain configurations, the current gain mode can be used as in
Figure 10 below.
Electret
Microphone
MIC_BIAS[2:0]
0x1488
W681308
MIC_RES[7:4]
0x1488
MCP
I_S
I_S
MIC_GAIN[7:4]
0x1489
R_INT
Current Gain Mode
0x1489
MIC_MODE=‘010’or ‘011’
+
To ADC
-
Rinternal
0x1489
Rm
0 Ohm
Or ferrite
MCO
RGND
250 Ohm
VADC
= −(REXT + 250)
IS _'011'
VADC
= − RINT
IS _'010'
REXT > 20 kΩ
Figure 10 Microphone Current Gain Mode
45
Rev1.2