Datasheet

PGA
0/+40 dB
0.5 dBsteps
ADC
AGC
PGA
0/+40 dB
0.5 dBsteps
ADC
AGC
+
-
+
+
-
+
+
--
+
--
IN1L(P)
IN2L
IN1R(M)
IN1L(P)
IN1R(M)
IN1L(P)
IN2L
IN1R(M)
IN1L(P)
IN1L(P)
IN1R(M)
IN1R(M)
Allcoarsestageattenuationsaresetto0dB,-6dB,orOffbyregistersetting.
Thedefaultisalltheswitchesareoffatstartup.
TLV320ADC3001
SLAS548C –OCTOBER 2008– REVISED APRIL 2011 www.ti.com
Figure 33. TLV320ADC3001 Available Audio Input Path Configurations
Table 4. TLV320ADC3001 Audio Signals
Audio Signals Available to
Audio Signals Available to Left ADC
Right ADC
Single-Ended Inputs Differential Inputs Single-Ended Inputs Differential Inputs
IN1L(P) IN1L(P), IN1R(M) IN1R(M) IN1L(P), IN1R(M)
IN2L IN1L(P)
IN1R(M)
Inputs can 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. However, it is possible for an input to be selected or mixed into both left- and right-channel PGAs, as
long as it has the same configuration for both channels (either both single-ended or both fully differential).
INPUT IMPEDANCE AND VCM CONTROL
The TLV320ADC3001 includes several programmable settings to control analog input pins, particularly when
they are not selected for connection to an ADC PGA. The default option allows unselected inputs to be put into a
high-impedance state, such that the input impedance seen looking into the device is extremely high. Note,
however, that the pins on the device do include protection diode circuits connected to AVDD and AVSS. Thus, if
any voltage is driven onto a pin approximately one diode drop (~0.6 V) above AVDD or one diode drop below
AVSS, these protection diodes will begin conducting current, resulting in an effective impedance that no longer
appears as a high-impedance state.
Another programmable option for unselected analog inputs is to weakly hold them at the common-mode input
voltage of the ADC PGA (which is determined by an internal band-gap voltage reference). This is useful to keep
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