Texas Instruments SLOU121 - Manual (Page 32)

Using the TPA6011A4 EVM With the Plug-N-Play Evaluation Platform
3-12 Details
3.3.2.3 J2 — Input Mode Jumper
To force the module amplifier IC to use the HP input regardless of the module
control input state, set jumper J2 to ON.
Jumper J2 connects the HP/LINE input mode control pin on the amplifier IC
directly to V
DD
, so that when J2 is ON, the IC is held in the HP input mode
regardless of the state of the HP/LINE module control input. When J2 is OFF,
a pulldown resistor on the module holds the IC input control mode input pin low,
allowing the IC to use the LINE inputs as the source of an input signal.
3.3.2.4 J3 — Input and Output Mode Jumper
To force the module amplifier IC to use the HP input when in SE output mode
and to use the LINE input when in BTL output mode, set jumper J3 to ON.
When jumper J3 is ON, the HP/LINE input mode control pin on the amplifier
IC and the SE/BTL output mode control pin on the amplifier IC are shorted
together so that both the input and output multiplexors switch simultaneously.
When J3 is OFF, the input and output modes may be switched independently
of each other.
3.3.2.5 J4 — Fade Mode Jumper
A fade mode slowly ramps up the amplifier gain when coming out of shutdown
mode and conversely ramps the gain down when going into shutdown. This
mode provides a smooth transition between the active and shutdown states
and virtually eliminates any pops or clicks on the outputs.
Jumper J4 connects the FADE input control pin on the amplifier IC directly to
GND, so that when J4 is ON, the IC is held in fade mode and the gain slowly
ramps when entering/leaving the shutdown state. When J4 is OFF, a pullup
resistor on the module holds the FADE input at V
DD
and the amplifier switches
to non-fade mode.
3.3.3 Signal Routing
Signal flow on the platform is controlled by two signal routing switches, as
shown in Figure 3–7.
Figure 3–7. Platform Signal Routing and Outputs
U1
Signal
Conditioning
On
Off
U5
Stereo
Headphone
Amplifier
S2
R
L
R
L
L
U5
U2 – U4
S3
J10
Headphone
Output
R
L
Audio
Input
R
L
J7, J8, J9
Speaker
Outputs
R
+
+
–
–
U2
TPA6011A4
Amplifier EVM
+
+
–
–
GND