1 Introduction
The TLV320AIC23B is a high-performance stereo audio codec with highly integrated analog functionality. The
analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) within the TLV320AIC23B use multibit
sigma-delta technology with integrated oversampling digital interpolation filters. Data-transfer word lengths of 16, 20,
24, and 32 bits, with sample rates from 8 kHz to 96 kHz, are supported. The ADC sigma-delta modulator features
third-order multibit architecture with up to 90-dBA signal-to-noise ratio (SNR) at audio sampling rates up to 96 kHz,
enabling high-fidelity audio recording in a compact, power-saving design. The DAC sigma-delta modulator features
a second-order multibit architecture with up to 100-dBA SNR at audio sampling rates up to 96 kHz, enabling
high-quality digital audio-playback capability, while consuming less than 23 mW during playback only. The
TLV320AIC23B is the ideal analog input/output (I/O) choice for portable digital audio-player and recorder
applications, such as MP3 digital audio players.
Integrated analog features consist of stereo-line inputs with an analog bypass path, a stereo headphone amplifier,
with analog volume control and mute, and a complete electret-microphone-capsule biasing and buffering solution.
The headphone amplifier is capable of delivering 30 mW per channel into 32
Ω.
The analog bypass path allows use
of the stereo-line inputs and the headphone amplifier with analog volume control, while completely bypassing the
codec, thus enabling further design flexibility, such as integrated FM tuners. A microphone bias-voltage output
provides a low-noise current source for electret-capsule biasing. The AIC23B has an integrated adjustable
microphone amplifier (gain adjustable from 1 to 5) and a programmable gain microphone amplifier (0 dB or 20 dB).
The microphone signal can be mixed with the output signals if a sidetone is required.
While the TLV320AIC23B supports the industry-standard oversampling rates of 256 f
s
and 384 f
s
, unique
oversampling rates of 250 f
s
and 272 f
s
are provided, which optimize interface considerations in designs using TI C54x
digital signal processors (DSPs) and universal serial bus (USB) data interfaces. A single 12-MHz crystal can supply
clocking to the DSP, USB, and codec. The TLV320AIC23B features an internal oscillator that, when connected to a
12-MHz external crystal, provides a system clock to the DSP and other peripherals at either 12 MHz or 6 MHz, using
an internal clock buffer and selectable divider. Audio sample rates of 48 kHz and compact-disc (CD) standard 44.1
kHz are supported directly from a 12-MHz master clock with 250 f
s
and 272 f
s
oversampling rates.
Low power consumption and flexible power management allow selective shutdown of codec functions, thus
extending battery life in portable applications. This design solution, coupled with the industry’s smallest package, the
TI proprietary MicroStar Junior using only 25 mm
2
of board area, makes powerful portable stereo audio designs
easily realizable in a cost-effective, space-saving total analog I/O solution: the TLV320AIC23B.
1.1 Features
•
High-Performance Stereo
Codec
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90-dB SNR Multibit Sigma-Delta ADC (A-weighted at 48 kHz)
100-dB SNR Multibit Sigma-Delta DAC (A-weighted at 48 kHz)
1.42 V – 3.6 V Core Digital Supply: Compatible With TI C54x DSP Core Voltages
2.7 V – 3.6 V Buffer and Analog Supply: Compatible Both TI C54x DSP Buffer Voltages
8-kHz – 96-kHz Sampling-Frequency Support
2-wire-Compatible and SPI-Compatible Serial-Port Protocols
Glueless Interface to TI McBSPs
I
2
S-Compatible Interface Requiring Only One McBSP for both ADC and DAC
Standard I
2
S, MSB, or LSB Justified-Data Transfers
16/20/24/32-Bit Word Lengths
Software Control Via TI McBSP-Compatible Multiprotocol Serial Port
Audio-Data Input/Output Via TI McBSP-Compatible Programmable Audio Interface
MicroStar Junior is a trademark of Texas Instruments.
1−1
TI [ TEXAS INSTRUMENTS ]
