Datasheet

11.9. Analogue Audio Input Path
The codec supports five Analogue Audio Input paths:
 LINEINL/R
 MIC1P/N,MIC2P/N
11.9.1. Microphone Input
MICIN1P/N, MICIN2P/N provide differential input that can be mixed into the ADC record mixer, or DAC
output mixer. MICIN is high impedance, low capacitance input suitable for connection to a wide range of
differential microphones of different dynamics and sensitive. There are two microphone pre-amplifiers for
the 2 differential microphone inputs. MICIN1P/N are input to the first pre-amplifier, MICIN2P/N
multiplexed as digital pin DMICCLK/DMICDAT are input to the 2nd pre-amplifier . Each microphone
pre-amplifier has a separate enable bit, ADC_SRCBST_CTRL Bit15 & Bit11. The gain for each
pre-amplifer can be set independently using MIC1BOOST, MIC2BOOST. MBIAS provide reference
voltage for electret condenser type(ECM) microphones.
Figure 25 Suggested External Microphone Input
11.9.2. LINEINL/R Input
LINEINL/R provide one-channel mono differential input or stereo single-ended input that can be mixed
into the ADC record mixer or the stereo output mixer. The inputs are suited to receiving line level signals
such as external audio equipment or baseband module .
When the linein input is set as differential signal input LINEINL-LININR to the ADC or to DAC mixer, the
linein gain is logarithmically adjustable from -9dB to 12dB in 1.5dB step by the register
LINEIN_DIFF_PREG set.