SLAS510G March 2007 – February 2021 TLV320AIC3104
The output common-mode voltage and output range of the analog output are determined by an internal band-gap reference, in contrast to other codecs that may use a scaled version of the analog supply. This scheme is used to reduce the coupling of noise that may be on the supply (such as 217-Hz noise in a GSM cellphone) into the audio signal path.
However, due to the possible wide variation in analog supply range (2.7 V–3.6 V), an output common-mode voltage setting of 1.35 V, which would be used for a 2.7 V supply case, would be overly conservative if the supply is actually much larger, such as 3.3 V or 3.6 V. In order to optimize device operation, the TLV320AIC3104 includes a programmable output common-mode level, which can be set by register programming to a level most appropriate to the actual supply range used by a particular customer. The output common-mode level can be varied among four different values, ranging from 1.35 V (most appropriate for low supply ranges, near 2.7 V) to 1.8 V (most appropriate for high supply ranges, near 3.6 V). Note that the recommended DVDD voltage is dependent on the CM setting; see Table 10-5.
|CM SETTING||RECOMMENDED AVDD, DRVDD||RECOMMENDED DVDD|
|1.35||2.7 V–3.6 V||1.525 V–1.95 V|
|1.5||3 V–3.6 V||1.65 V–1.95 V|
|1.65 V||3.3 V–3.6 V||1.8 V–1.95 V|
|1.8 V||3.6 V||1.95 V|