Datasheet

MUTE

FAULT

ExternalGPIO

Control

TPA3106D1

SLOS516C –OCTOBER 2007–REVISED AUGUST 2010

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MUTE OPERATION

The MUTE pin is an input for controlling the output state of the TPA3106D1. A logic high on this terminal

disables the outputs. A logic low on this pin enables the outputs. This terminal may be used as a quick

disable/enable of outputs when changing channels on a television or transitioning between different audio

sources.

The MUTE terminal should never be left floating. For power conservation, the SHUTDOWN terminal should be

used to reduce the quiescent current to the absolute minimum level.

The MUTE terminal can also be used with the FAULT output to automatically recover from a short-circuit event.

When a short-circuit event occurs, the FAULT terminal transitions high indicating a short-circuit has been

detected. When directly connected to MUTE, the MUTE terminal transitions high, and clears the internal fault

flag. This causes the FAULT terminal to cycle low, and normal device operation resumes if the short-circuit is

removed from the output. If a short remains at the output, the cycle continues until the short is removed.

If external MUTE control is desired, and automatic recovery from a short-circuit event is also desired, an OR gate

can be used to combine the functionality of the FAULT output and external MUTE control, see Figure 33.

Figure 33. External MUTE Control

MSTR/SLV and SYNC operation

The MSTR/SLV and SYNC terminals can be used to synchronize the frequency of the class-D output switching

when using multiple amplifiers in a single application. When the MSTR/SLV terminal is high, the output switching

frequency is determined by the selection of the resistor connected to the ROSC terminal (see ROSC Resistor

Selection). The SYNC terminal becomes an output in this mode, and the frequency of this output is also

determined by the selection of the ROSC resistor. This TTL compatible, push-pull output can be connected to

other TPA310X devices such as TPA3100D2, configured in slave mode. The output switching is synchronized to

avoid beat frequencies that could occur in the audio band when two class-D amplifiers in the same system are

switching at slightly different frequencies.

When the MSTR/SLV terminal is low, the output switching frequency is determined by the incoming square wave

on the SYNC input. The SYNC terminal becomes an input in this mode and accepts a TTL compantible square

wave from another TPA310X audio amplifier configured in teh master mode or from an external GPIO. If

connecting to an external GPIO, recommended frequencies are 200 kHz to 300 kHz for proper device operation,

and the maximum amplitude is 4 V.

The sync drive on the TPA3106D1 has been improved relative to other TPA310X devices, so please use the

TPA3106D1 as the MASTER when connected in synchronous operation with other device of the TPA310X

family.

USING LOW-ESR CAPACITORS

Low-ESR capacitors are recommended throughout this application section. A real (as opposed to ideal) capacitor

can be modeled simply as a resistor in series with an ideal capacitor. The voltage drop across this resistor

minimizes the beneficial effects of the capacitor in the circuit. The lower the equivalent value of this resistance,

the more the real capacitor behaves like an ideal capacitor.

Product Folder Link(s): TPA3106D1