WM8753L
Advanced Information
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R47 (2Fh)
Mic Input Boost
[8:7]
MIC2BOOST[1:0]
00
MIC2 Preamp Gain Control
00 : +12dB
01 : +18dB
10 : +24dB
11 : +30dB
MIC1BOOST[1:0]
00
MIC1 Preamp Gain Control
00 = +12dB
[6:5]
01 = +18dB
10 = +24dB
11 = +30dB
Table 10 MIC Preamp Gain Control
The suggested configuration for the external microphone circuit is shown in Figure 7.
Figure 7 Suggested External Microphone Input Configuration
DIFFERENTIAL OPERATION
It is possible to connect up to two mics differentially. Microphone1 is connected between the MIC1
and MIC1N inputs and microphone2 is connected between the MIC2 and MIC2N inputs. It should be
noted that in differential mode, with mic inputs routed to the ADCs, an extra invert occurs in the MIC1
(left ADC) path due to the extra mixer. This can be compensated for by inverting the left ADC signal
back again using ADCPOL.
AI Rev 3.1 June 2004
25
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
