Texas Instruments SLOU082 - Manual (Page 20)

Plug-N-Play Platform Inputs and Outputs
3-6 Details
3.6 Module Switches
The TPA032D03 mono class-D audio amplifier evaluation module is equipped
with two pushbutton switches that allow the module shutdown and mute
functions to be manually activated.
3.6.1 S1 — Shutdown Switch
To have the module amplifier IC enter the shutdown mode, press the
Shutdown switch (S2) on the module. S2 connects the amplifier IC
SHUTDOWN pin to ground, forcing it into a low-power state. This function can
be controlled by an external control input to the SD module pin.
The shutdown mode reduces the amplifier IC current consumption to less than
1
µ
A compared to approximately 2.5 mA in the mute mode. The EVM
shutdown current is based on V
CC,
V
DD,
R2, R5, and R6, and capacitor
leakage currents, but will typically be 97
µ
A
±
5% for V
CC
= 12 V and V
DD
= 5
V. The plug-n-play platform typically draws 60 mA of current.
3.6.2 S2 — Mute Switch
Pushbutton switch S1 on the TPA032D03 class-D EVM allows manual muting
of the amplifier IC. S1 connects the amplifier IC MUTE pin to ground, muting
the output. The EVM Mute control input pin also allows external control of this
function.
In the mute mode, the amplifier IC lowside output transistors are turned on,
shorting the load to ground. This reduces the EVM current to 2.5 mA.
3.6.3 J1 — Headphone Jack Mode Switch
EVM headphone jack J1 is equipped with an internal switch that grounds the
amplifier MODE pin
until a plug is inserted into the jack. When a plug is inserted
into the headphone jack, the IC MODE pin goes high and the IC headphone
amplifier goes active and the class-D amplifier shuts off.