TLV320AIC3104_17 Datasheet, PDF (32/97 Pages) Texas Instruments – Low-Power Stereo Audio Codec for Portable Audio and Telephony

TLV320AIC3104
SLAS510F – FEBRUARY 2007 – REVISED DECEMBER 2016
www.ti.com
Table 5. Appropriate Settings (continued)
CM SETTING
1.65 V
1.8 V
RECOMMENDED AVDD, DRVDD
3.3 V–3.6 V
3.6 V
RECOMMENDED DVDD
1.8 V–1.95 V
1.95 V
10.3.4.7 Audio DAC Power Control
The stereo DAC can be fully powered up or down, and in addition, the analog circuitry in each DAC channel can
be powered up or down independently. This provides power savings when only a mono playback stream is
needed.
10.3.5 Audio Analog Inputs
The TLV320AIC3104 includes six single-ended audio inputs. These pins connect through series resistors and
switches to the virtual ground terminals of two fully differential operational amplifiers (one per ADC/PGA
channel). By selecting to turn on only one set of switches per operational amplifier at a time, the inputs can be
multiplexed effectively to each ADC/PGA channel.
By selecting to turn on multiple sets of switches per operational amplifier at a time, mixing can also be achieved.
Mixing of multiple inputs can easily lead to PGA outputs that exceed the range of the internal operational
amplifiers, resulting in saturation and clipping of the mixed output signal. Whenever mixing is being implemented,
the user should take adequate precautions to avoid such saturation from occurring. In general, the mixed signal
should not exceed 2 Vp-p (single-ended).
In most mixing applications, there is also a general need to adjust the levels of the individual signals being
mixed. For example, if a soft signal and a large signal are to be mixed and played together, the soft signal
generally should be amplified to a level comparable to the large signal before mixing. In order to accommodate
this need, the TLV320AIC3104 includes input level control on each of the individual inputs before they are mixed
or multiplexed into the ADC PGAs, with gain programmable from 0 dB to –12 dB in 1.5-dB steps. Note that this
input level control is not intended to be a volume control, but instead used occasionally for level setting. Soft-
stepping of the input level control settings is implemented in this device, with the speed and functionality
following the settings used by the ADC PGA for soft-stepping.
Figure 21 shows the single-ended mixing configuration for the left-channel ADC PGA, which enables mixing of
the signals LINE1L, LINE2L, LINE1R. The right-channel ADC PGA mix is similar, enabling mixing of the signals
LINE1R, LINE2R, LINE1L.
Gain = 0, –1.5, –3, . . ., –12 dB, Mute
MIC1L/LINE1L
Gain = 0, –1.5, –3, . . ., –12 dB, Mute
MIC2L/LINE2L/MICDET
To Left ADC PGA
Gain = 0, –1.5, –3, . . ., –12 dB, Mute
MIC1R/LINE1R
B0156-01
Figure 21. Left-Channel, Single-Ended Analog Input Mixing Configuration
10.3.6 Analog Fully Differential Line Output Drivers
The TLV320AIC3104 has two fully differential line output drivers, each capable of driving a 10-kΩ differential
load. The output stage design leading to the fully differential line output drivers is shown in Figure 22 and
Figure 23. This design includes extensive capability to adjust signal levels independently before any mixing
occurs, beyond that already provided by the PGA gain and the DAC digital volume control.
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