Low Power Codec with Speaker and
Headphone Amplifier
ADAU1373
FEATURES
Eight single-ended or four differential analog inputs with PGAs
are provided for adjusting the gain from −12 dB to +18 dB. They
can be configured for microphones or line level signals.
1 stereo ADC and 2 stereo DACs with sampling rates
from 8 kHz to 48 kHz
Low power: 7 mW record, 6 mW playback, 48 kHz at 1.8 V
8 single-ended or 4 differential inputs with PGA
2 microphone bias reference voltages with current sense
2 stereo digital microphone inputs
Two stereo digital microphone inputs are supported; four digital
microphones can be connected in total. In addition, three serial
digital audio input/output ports are provided with asynchronous
sample rate converters (ASRCs) to support various sampling rates,
allowing for flexible system design in mobile phone applications.
The inputs can be mixed and selected before the ADC or con-
figured to bypass the ADC. Two stereo DACs are included, with
a flexible mixing option for routing the signals internally.
Flexible analog input/output mixers
1 stereo differential or 2 stereo single-ended line outputs
True ground-centered stereo Class-G headphone amplifier,
capable of 2 × 50 mW into 16 Ω at 1.8 V, 10% THD
Filterless stereo Class-D speaker amplifier, capable of 2 ×
880 mW into 8 Ω at 3.6 V, 10% THD
Differential earpiece amplifier capable of driving 32 Ω
2 PLLs, supporting input clocks from 8 kHz to 27 MHz
I2C control interface
The analog output side consists of line outputs, headphone output,
speaker output, and receiver output. Two stereo single-ended
line level outputs, which can be configured as two differential
outputs, are included. The headphone output is stereo true ground
centered (eliminating the need for coupling capacitors), with
efficient Class-G (rail switching) architecture. The efficient stereo
filterless Class-D switching amplifier provides ~1 W of stereo
power for speakers. The differential receiver amplifier can be
used to connect the separate receiver speaker. Two PLL blocks,
which can lock to the inputs from 8 kHz to 27 MHz, are included.
Digital audio processing
3 digital audio input and output ports with ASRC
I2S, PCM, right-justified, left-justified modes
4.05 mm × 3.82 mm, 81-ball, 0.4 mm pitch WLCSP package
−40°C to +85°C operating temperature range
APPLICATIONS
The DSP allows system designers to compensate for the real-world
limitations of microphones, speakers, amplifiers, and listening
environments, resulting in a dramatic improvement in perceived
audio quality through equalization, multiband compression, and
limiting algorithms. The SigmaStudio™ graphical development tool,
which includes audio processing blocks such as filters, mixers,
dynamics processors, and amplifiers for fast development of
custom signal flows, is used to program the ADAU1373.
Mobile phones, tablet PCs, e-books, portable media players
GENERAL DESCRIPTION
The ADAU1373 is a low power, stereo audio codec with integrated
digital audio processing that supports stereo 48 kHz record and
playback. The stereo audio ADCs and DACs support sampling
rates from 8 kHz to 48 kHz, as well as a digital volume control.
FUNCTIONAL BLOCK DIAGRAM
EARPIECE
AMP
SERIAL
DIGITAL
AUDIO
EPP
EPN
BCLKA/BCLKB/BCLKC
LRCLKA/LRCLKB/LRCLKC
SDATAINA/SDATAINB/SDATAINC
LINEOUT2
LINEOUT1
INTERFACE
INPUT
OUTPUT
MUX
A
LOUT1L/LOUTLP, LOUT2L/LOUTLN
LOUT1R/LOUTRP, LOUT2R/LOUTRN
LN1FBIN, LN2FBIN
FDSP
SDATAOUTA/SDATAOUTB/SDATAOUTC
DIGITAL
MICROPHONE
MUX
MIX
DMIC1_2_DATA
DMIC3_4_DATA
DMIC_CLK
HEADPHONE
AMP
HPL
SGND
HPR
MUX
DAC1
ADC
I2C
MIX
SPEAKER
AMP
SPKLP
SPKLN
SPKRP
SPKRN
MICBIAS1, MICBIAS2
DAC2
GPIO
PLLA
ANALOG
INPUTS
AIN1L/AIN1P TO AIN4L/AIN4P
AIN1R/AIN1N TO AIN4R/AIN4N
Figure 1.
Rev. 0
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