Texas Instruments SLOU121 - Manual (Page 26)

The TPA6011A4 Audio Power Amplifier Evaluation Module
3-6 Details
SEDIFF and SEMAX pins control the singe-ended gain proportional to the gain
set by the voltage on the VOLUME pin. When SEDIFF = 0 V, the difference
between the BTL gain and the SE gain is 6 dB. The voltage on the SEDIFF
terminal is subtracted from the voltage on the VOLUME terminal and the value
is used to determine the SE gain. Turning the potentiometer R6 in the clock-
wise direction decreases the voltage on the SEDIFF terminal, resulting in a
higher volume in the single-ended mode of operation. The voltage on the SE-
DIFF terminal is subtracted from the voltage on the VOLUME terminal and the
value is used to determine the SE gain.
The SEMAX terminal controls the maximum gain for single ended mode. Turn-
ing potentiometer R7 in the clockwise direction increases the voltage on the
SEMAX terminal, resulting in a higher volume limit for single-ended operation.
The functionality of the SEDIFF and SEMAX pin are combined to set the SE
gain. A block diagram of the combined functionality is shown in Figure 3–5.
The value obtained from the block diagram for SE_VOLUME is a dc voltage
that can be used to determine the SE gain using Table 3–2. Again, the voltages
listed in the table are for V
DD
= 5 V. The values must be scaled for other V
DD
voltages.
Figure 3–5. Block Diagram of SE Volume Control
Is SEMAX>
(VOLUME–SEDIFF)?
SEMAX (V)
VOLUME–SEDIFF
SEDIFF (V)
–
+ VOLUME (V)
NO
YES
SE_VOLUME (V) = VOLUME (V) – SEDIFF (V)
SE_VOLUME (V) = SEMAX (V)