ZHCSIA0A May 2018 – November 2018 TAS3251
PRODUCTION DATA.
The mono mode of operation is used to describe operation in which the two outputs of the device are placed in parallel with one another to increase the power sourcing capabilities of the audio output channel. This is also known as Parallel Bridge Tied Load (PBTL).
On the output side of the TAS3251 device, the summation of the devices can be done before the filter in a configuration called Pre-Filter PBTL. However, the two outputs may be required to merge together after the inductor portion of the output filter. Doing so does require two additional inductors, but allows smaller, less expensive inductors to be used because the current is divided between the two inductors. This process is called Post-Filter PBTL. Both variants of mono operation are shown in Figure 39 and Figure 40.
On the input side of the TAS3251 device, the input signal to the mono amplifier can be selected from the any slot in a TDM stream or the left or right frame from an I2S, LJ, or RJ signal. The TAS3251 device can also be configured to amplify some mixture of two signals, as in the case of a subwoofer channel which mixes the left and right channel together and sends the mixture through a low-pass filter to create a mono, low-frequency signal.