NXP Semiconductors TFA9812 User Manual

Tfa9812, General description, Features

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General description

The TFA9812 is a high-efficiency Bridge Tied Load (BTL) stereo Class-D audio amplifier
with a digital I


S audio input. It is available in a HVQFN48 package with exposed die

paddle. The exposed die paddle technology enhances the thermal and electrical
performances of the device.

The TFA9812 features digital sound processing and audio power amplification. It supports


C control mode and Legacy mode. In Legacy mode I


C involvement is not needed

because the key features are controlled by hardware pin connections.

A continuous time output power of 2


12 W (R


= 8

, V


= 15 V) is supported without

an external heat sink. Due to the implementation of a programmable thermal foldback
even for high supply voltages, higher ambient temperatures, and/or lower load
impedances, the device operates without sound interrupting behavior.

TFA9812 is designed in such a way that it starts up easily (no special power-up sequence
required). It features various soft and hard impact protection mechanisms to ensure an
application that is both user friendly and robust.

A modulation technique is applied for the TFA9812, which supports common mode choke
approach (1 common mode choke only per BTL amplifier stage). This minimizes the
number of external components.



2.1 General features

3.3 V and 8 V to 20 V external power supply

High efficiency and low power dissipation

Speaker outputs fully short circuit proof across load, to supply lines and ground

Pop noise free at power-up/power-down and sample rate switching

Low power Sleep mode

Overvoltage and undervoltage protection on the 8 V to 20 V power supply

Undervoltage protection on the 3.3 V power supply

Overcurrent protection (no audible interruptions)

Overdissipation protection

Thermally protected and programmable thermal foldback

Clock error protection



C mode control or Legacy mode (i.e. no I


C) control

Four different I


C addresses supported

Internal Phase-Locked Loop (PLL) without using external components


BTL stereo Class-D audio amplifier with I


S input

Rev. 02 — 22 January 2009

Preliminary data sheet

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