TLV320AIC3254 Datasheet, PDF (26/168 Pages) Texas Instruments – Ultra Low Power Stereo Audio Codec With Embedded miniDSP

TLV320AIC3254
Ultra Low Power Stereo Audio Codec With Embedded miniDSP
SLAS549A – SEPTEMBER 2008 – REVISED OCTOBER 2008
5.4 ANALOG ROUTING
IN1_L
IN2_L
IN3_L
IN3_R
IN2_R
IN1_R
Vol Ctrl 0… -72dB
Mixer Amp
0..-30dB
IN1_R
IN2_R
IN3_R
CM2L
CM1L
CM1R
CM2R
IN3_L
IN1_L
IN2_L
P
M+ic PGA
0...47.5 dB
N
-
LeftLAADDCC
P
Left DAC
N
Left Channel, Input Options:
Single Ended:
IN1_L or IN2_L or IN3_L or IN1_R
Differential:
IN2_L and IN2_R or
IN3_L and IN3_R
1,10,6
CM
Right Channel, Input Options:
Single Ended:
IN1_R or IN2_R or IN3_R or IN2_L
Differential:
IN1_R and IN1_L or
IN3_R and IN3_L
N
M+ic PGA
0...47.5 dB
P
-
LeftLAADDCC
Mixer Amp
0..-30dB
P
Right DAC
N
IN1L
MAL
LDAC
MA R
CM HP
Headphone
Amplifier
-6dB … + 29 dB
MAL
LDAC
RDAC
LOR
CM LO
Line Out
Amplifier
-6dB … + 29 dB
RDAC
MA R
Line Out
Amplifier
-6dB … + 29 dB
HPL
LDAC
RDAC
MA R
IN1R
CM HP
Headphone
Amplifier
-6dB … + 29 dB
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AVDD
LDOIN
HPL
LOL
LOR
HPR
Vol Ctrl 0… -72dB
Figure 5-2. Analog Routing Diagram
5.4.1 Analog Low Power Bypass
The TLV320AIC3254 offers two analog-bypass modes. In either of the modes, an analog input signal can
be routed from an analog input pin to an amplifier driving an analog output pin. Neither the ADC nor the
DAC resources are required for such operation; this supports low-power operation during analog-bypass
mode.
In analog low-power bypass mode, line-level signals can be routed directly from the analog inputs IN1L to
the left headphone amplifier (HPL) and IN1R to HPR. This is configured on Page 1, Register 12, D(2) for
the left channel and Page 1, Register 13, D(2) for the right channel
5.4.2 ADC Bypass Using Mixer Amplifiers
In addition to the low-power bypass mode, there is a bypass mode that uses the programmable gain
amplifiers of the input stage in conjunction with a mixer amplifier. With this mode, microphone-level signals
can be amplified and routed to the line or headphone outputs, fully bypassing the ADC and DAC.
To enable this mode, the mixer amplifiers are powered on (Page1, Register 9, D(0:1).
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Application Information
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