NXP Semiconductors TFA9812 - Manual

1. General description
The TFA9812 is a high-efficiency Bridge Tied Load (BTL) stereo Class-D audio amplifier
with a digital I
2 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
I
2 C control mode and Legacy mode. In Legacy mode I 2 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
L
= 8
Ω
, V
DDP
= 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. Features
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
■
I 2 C mode control or Legacy mode (i.e. no I 2 C) control
■
Four different I 2 C addresses supported
■ Internal Phase-Locked Loop (PLL) without using external components
TFA9812
BTL stereo Class-D audio amplifier with I 2 S input
Rev. 02 — 22 January 2009 Preliminary data sheet