ZHCSGM5A August 2017 – November 2017 TLV320AIC3109-Q1
PRODUCTION DATA.
The TLV320AIC3109-Q1 has two fully differential line output drivers, each capable of driving a 10-kΩ differential load. Figure 21 and Figure 22 illustrate the output stage design leading to the fully differential line output drivers. 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.
The PGA signal refers to the output of the ADC PGA stage that is passed around the ADC to the output stage. PGA_AUX is the output of the auxiliary PGA. The DAC output can be sent to the output driver and mixed with the PGA or PGA_AUX signal. Undesired signals can also be disconnected from the MIX through register control.
The DAC signal is the output of the mono audio DAC that can be steered by register control based on the requirements of the system. If mixing of the DAC audio with other signals is not required, and the DAC output is only needed at the mono line outputs, then use the routing through the DAC_3 path to the fully differential line outputs. This configuration results in lower-power operation because the analog volume controls and mixing blocks ahead of these drivers can be powered down.
If instead the DAC analog output must be routed to multiple output drivers simultaneously (such as to LEFT_LOP, LEFT_LOM and RIGHT_LOP, RIGHT_LOM) or must be mixed with other analog signals, then switch the DAC outputs through the DAC_1 path. This option provides the maximum flexibility for routing of the DAC analog signals to the output drivers.
The TLV320AIC3109-Q1 includes an output level control on each output driver with limited gain adjustment from 0 dB to 9 dB. The output driver circuitry in this device is designed to provide a low-distortion output when playing full-scale mono DAC signals at a 0-dB gain setting. However, a higher amplitude output can be obtained at the cost of increased signal distortion at the output. This output level control allows this tradeoff to be made based on the requirements of the end equipment. This output level control is not intended to be used as a standard output volume control, but is expected to be used only sparingly for level setting (that is, for adjustment of the full-scale output range of the device).
Each differential line output driver can be powered down independently of the others when not needed in the system. When placed into powerdown through register programming, the driver output pins are placed into a high-impedance state.