Datasheet

ADAU1381
Rev. B | Page 31 of 84
TO LEFT
ADC
TO RIGHT
ADC
PGA
LMIC/LMICN/
MICD1
LMICP
CM
PGA
RMIC/RMICN/
MICD2
RMICP
CM
0
8313-032
Figure 34. Differential Input Configuration
ANALOG-TO-DIGITAL CONVERTERS
The ADAU1381 uses two 24-bit Σ- analog-to-digital converters
(ADCs) with selectable oversampling rates of either 64× or 128×.
The full-scale input to the ADCs depends on AVDD1. At 3.3 V,
the full-scale input level is 1.0 V rms. Inputs greater than the
full-scale value result in clipping and distortion.
me Control
:0], right
e control.
The ADAU1381 includes an automatic level control (ALC). The
ALC adjusts the input gain continuously for a varying input signal
as dictated by the user-defined ALC settings. This allows the input
recording level to remain constant. Although this functionality
relates mainly to the record signal path, it is implemented digitally
in the sound engine.
Digital ADC Volu
The ADC output (digital input) volume can be adjusted in
Register 16410 (0x401A), left ADC attenuator, Bits[7:0], left ADC
digital attenuator, for the left channel digital volume control and
in Register 16411 (0x401B), right ADC attenuator, Bits[7
ADC digital attenuator, for right channel digital volum
High-Pass Filter
A high-pass filter is used in the ADC path to remove dc offsets
and can be selected in Register 16409 (0x4019), ADC control,
Bit 5, high-pass filter select, where it can be enabled or disabled.
DIGITAL DUAL-BAND AUTOMATIC LEVEL
CONTROL (ALC)