September 2007

Rev 1

1/5

AN2622

Application note

TS4909 low power stereo headphone amplifier

evaluation board user guidelines

Introduction

This application note concerns the DEMOTS4909 evaluation board, designed to evaluate

the TS4909 low power stereo headphone amplifier with capacitor-less output.

In this document, you will find:

About the TS4909

The TS4909 is a stereo audio amplifier designed to drive headphones in portable

applications.

The integrated phantom ground is a circuit topology that eliminates the heavy output

coupling capacitors. This is of primary importance in portable applications where space

constraints are very high. A single-ended configuration is also available, offering even lower

power consumption because the phantom ground can be switched off.

Specially designed for applications requiring low power supplies, the TS4909 is capable of

delivering 52mW of continuous average power into a 32

Ω load with less than 1% THD+N

from a 3V power supply. Pop & click noise during switch-on and switch-off phases is

eliminated thanks to integrated circuitry.

Key features of the TS4909 include:

– 158mW @5V, into 16

Ω with 1% THD+N max (1kHz)

– 52mW @3.0V into 32

Ω with 1% THD+N max (1kHz)

For complete information about the TS4909, refer to the datasheet.

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