Texas Instruments TPA701 manual 3.2.4Shutdown, Details

The TPA701 MSOP Audio Power Amplifier Evaluation Module

The TPA701 amplifier IC, like most other amplifiers, exhibits its best distortion and noise performance at lower gain levels (see the TPA701 data sheet). Even so, the TPA701 at its highest gain setting has significantly less distortion than most low-cost speakers.

Gain versus total harmonic distortion (THD) should be considered in each application. Both the module input signal level and the TPA701 MSOP module gain should be adjusted to obtain the lowest overall distortion level for a particular overall gain. A quick rule of thumb (everything else being equal): the module input signal level should be as high as possible without clipping or overloading the TPA701 input, and the TPA701 gain should be kept as low as possible.

3.2.4Shutdown

When the shutdown terminal of the TPA701 amplifier IC is taken high, the IC ceases operation and enters an ultra-low power state. This is accomplished by applying a control signal to the module Shutdown pin or by pressing the Shutdown switch, S1, on the module. When the control signal goes low or is removed (or the switch is released), amplifier operation resumes.

The Plug-N-Play platform can generate the shutdown (mute) signal for the module either when a plug is inserted into the platform headphone output jack or when the plug is removed, as selected by a platform jumper (JP8).

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