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Application Note Please read the Important Notice and Warnings at the end of this document Rev. 1.0
www.infineon.com 2016-10-19
DG_201610_PL16_02
IR43xx PowIRaudio™ Class D Amplifier IC
Functional Description
About this document
Scope and purpose
The purpose of his document is to provide a functional description and design guide to the IR43xx series
PowIRaudio Class D ICs.
Intended audience
Audio amplifier design engineers
Table of Contents
About this document .............................................................................................................................................1
Table of Contents ..................................................................................................................................................1
1 General Description ...........................................................................................................................3
2 Typical Implementation.....................................................................................................................5
3 PWM Modulator Design ......................................................................................................................7
3.1 Input Section ...........................................................................................................................................7
3.2 Control Loop Design................................................................................................................................8
3.3 PWM Frequency.......................................................................................................................................8
3.4 Clock Synchronization ............................................................................................................................9
3.5 Click Noise Elimination .........................................................................................................................10
3.6 Differential Input ...................................................................................................................................11
3.7 Output LPF.............................................................................................................................................12
4 Operational Mode ............................................................................................................................13
4.1 Self-oscillation Start-up Condition....................................................................................................... 13
5 Protections.......................................................................................................................................14
5.1.1 Self-Reset Protection .......................................................................................................................15
5.1.2 Designing Ct......................................................................................................................................16
5.1.3 Shutdown Input ...............................................................................................................................16
5.1.4 Latched Protection...........................................................................................................................17
5.1.5 Interfacing with System Controller .................................................................................................17
5.2 Over Current Protection (OCP) .............................................................................................................18
5.3 Over Temperature Protection (OTP) ....................................................................................................19
5.4 Under Voltage Protection (UVP) ...........................................................................................................19
5.5 Over Voltage Protection (OVP)..............................................................................................................19
6 Status Output (IR43x2 Only).............................................................................................................20
6.1 Fault Output ..........................................................................................................................................20
6.2 CLIP Output ...........................................................................................................................................21
7 Power Supply Design .......................................................................................................................22
7.1 Supplying VAA and VSS .........................................................................................................................22
7.2 Supplying VCC and VB ........................................................................................................................... 22
