TLV320AIC34 Datasheet, PDF (39/91 Pages) Texas Instruments – FOUR-CHANNEL, LOW-POWER AUDIO CODEC FOR PORTABLE AUDIO/TELEPHONY

TLV320AIC34
www.ti.com
SLAS538 – OCTOBER 2007
Inputs can also be selected as single-ended instead of fully differential, and mixing or multiplexing into the ADC
PGAs is also possible in this mode. It is not possible, however, for an input pair to be selected as fully differential
for connection to one ADC PGA and simultaneously selected as single-ended for connection to the other ADC
PGA channel in the same partition. However, it is possible for an input to be selected or mixed into both left- and
right-channel PGAs of the same partition, as long as it has the same configuration for both channels (either both
single-ended or both fully differential).
Figure 31 shows the single-ended mixing configuration for one partition's left-channel ADC PGA, which enables
mixing of the signals LINE1LP, LINE2LP, LINE1RP, MIC3L, and MIC3R. The right-channel ADC PGA mix is
similar, enabling mixing of the signals LINE1RP, LINE2RP, LINE1LP, MIC3L, and MIC3R.
Gain = 0, –1.5, –3, . . ., –12 dB, Mute
LINE1LP
Gain = 0, –1.5, –3, . . ., –12 dB, Mute
LINE2LP
Gain = 0, –1.5, –3, . . ., –12 dB, Mute
LINE1RP
To Left ADC PGA
Gain = 0, –1.5, –3, . . ., –12 dB, Mute
MIC3L
Gain = 0, –1.5, –3, . . ., –12 dB, Mute
MIC3R
B0156-04
Figure 31. Left-Channel Single-Ended Analog Input Mixing Configuration
ANALOG INPUT BYPASS PATH FUNCTIONALITY
The TLV320AIC34 includes the additional ability to route some analog input signals past the integrated data
converters, for mixing with other analog signals and then direct connection to the output drivers. This capability is
useful in a cell phone, for example, when a separate FM radio device provides a stereo analog output signal that
must be routed to headphones. The TLV320AIC34 supports this in a low-power mode by providing a direct
analog path through the device to the output drivers, while all ADCs and DACs can be completely powered down
to save power.
For fully differential inputs, the TLV320AIC34 provides the ability to pass the signals LINE1LP-LINE1LM and
LINE1RP-LINE1RM of each partition directly to the output stage of the same partition. If in single-ended
configuration, the device can pass the signal LINE1LP and LINE1RP to the output stage directly.
Copyright © 2007, Texas Instruments Incorporated
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