adau1361 Analog Devices, Inc., adau1361 Datasheet - Page 28

• Manufacturer Part Number: adau1361
• Description: Stereo, Low Power, 96 Khz, 24-bit Audio Codec With Integrated Pll
• Manufacturer: Analog Devices, Inc.

ADAU1361
The PGA can also be used for single-ended microphone inputs.
Connect LINP and/or RINP to the CM pin. In this configu-
ration, the signal connects to the inverting input of the PGA,
LINN and/or RINN, as shown in Figure 32.
Analog Line Inputs
Line input signals can be accepted by any analog input. It is
possible to route signals on the RINN, RINP, LINN, and LINP
pins around the differential amplifier to their own amplifier and
to use these pins as single-ended line inputs by disabling the
LDEN and RD
and Bit 0 in Register R9, Address 0x400F). Figure 33 depicts a
stereo single-ended line input using the RINN and LINN pins.
The LAUX and RAUX pins are single-ended line inputs. They
can be used together as a stereo single-ended auxiliary input, as
shown in Figure 33. These inputs can bypass the input gain
control, mixers, and ADCs to directly connect to the output
playback mixers (see auxiliary bypass in Figure 30).
MICROPHONE
MICROPHONE
MICROPHONE
MICROPHONE
Figure 32. Stereo Single-Ended Microphone Configuration
Figure 31. Stereo Differential Microphone Configuration
RIGHT
RIGHT
LEFT
LEFT
2kΩ
2kΩ
2kΩ
2kΩ
EN bits (Bit 0 in Register R8, Address 0x400E,
0.1µF
MICBIAS
MICBIAS
0.1µF
RINN
RINP
RINP
RINN
LINN
LINN
LINP
LINP
CM
RIGHT
RIGHT
LEFT
LEFT
PGA
PGA
PGA
PGA
–12dB TO
–12dB TO
–12dB TO
–12dB TO
+35.25dB
+35.25dB
+35.25dB
+35.25dB
ADAU1361
ADAU1361
RDBOOST[1:0]
RDBOOST[1:0]
LDBOOST[1:0]
LDBOOST[1:0]
0dB/20dB
0dB/20dB
0dB/20dB
0dB/20dB
MUTE/
MUTE/
MUTE/
MUTE/
Rev. 0 | Page 28 of 80
Digital Microphone Input
When using a digital microphone connected to the JACKDET/
MICIN pin, the JDFUNC[1:0] bits in Register R2 (Address 0x4008)
must be set to enable the microphone input and disable the jack
detection function. The ADAU1361 must operate in master mode
and source BCLK to the input clock of the digital microphones.
The digital microphone signal bypasses record path mixers and
ADCs and is routed directly into the decimation filters. The
digital microphone and ADCs share decimation filters and,
therefore, both cannot be used simultaneously. The digital
microphone input select bit, INSEL, can be set in Register R19
(ADC control register, Address 0x4019). Figure 34 depicts the
digital microphone interface and signal routing.
Figure 33. Stereo Single-Ended Line Input with Stereo Auxiliary Bypass
RIGHT
LEFT
ADC
ADC
Figure 34. Digital Microphone Interface Block Diagram
RIGHT LINE
RIGHT AUX
DETECTION
LEFT LINE
LEFT AUX
TO JACK
CIRCUIT
INPUT
INPUT
INPUT
INPUT
DECIMATORS
JACKDET/MICIN
DIGITAL MICROPHONE
CHANN
LEFT
RAUX
LAUX
RINN
LINN
INTERFACE
EL
CHANNEL
AUXILIARY
BYPASS
RIGHT
–12dB TO +6dB
–12dB TO +6dB
ADAU1361
R2: DIGITAL MICROPHONE/
RINNG[2:0]
LINNG[2:0]
R19: ADC CONTROL
JACK DETECTION
JDFUNC[1:0]
CONTROL
INSEL