August 2012

© 2011 Fairchild Semiconductor Corporation

www.fairchildsemi.com

FSA8049 • Rev. 1.0.2

FSA8049

Audio Jack Detection and Configuration, MIC / GND

Cross Point Switch

Features

Detection

Audio Plug GND & MIC Polarity

2.5 to 4.4 V

THD (MIC)

0.002% Typical

ESD (IEC 61000-4-2)

(Air Gap)

15 kV

Operating Temperature

-40°C to 85°C

Package

9-Ball WLCSP 3x3 Array, 0.4 mm

Terminal Pitch, 250 µm Ball

Top Mark

M3

Ordering Information

FSA8049UCX

Applications



Cellular Phones, Smart Phones



MP3 and Portable Multimedia Player

Description

The FSA8049 is an audio jack detection switch for 3- or

4-pole accessories. The FSA8049 detects the locations of

ground (GND) and microphone (MIC) poles on the audio

plug and automatically routes them to the appropriate

connections. This allows the end user to plug accessories,

such as headsets with different audio pole configurations,

into the mobile device and have them operate correctly.



Detects 3- or 4-pole audio accessories



Detects polarity of GND and MIC on 4-pole plugs



Automatically routes GND and MIC to audio jack terminals

Related Resources

Typical Application

Figure 1. Mobile Phone Example

Oscillator &

Logic

100m

Ω

MIC

GNDA

GND/MIC2

GND/MIC1

VDD

Detection

EN

Switch Enable

Timing

CEXT

Audio Jack

LSPKR

RSPKR

3Pole

4Pole

To Audio Plug

Detection Circuit

Audio

Sub System

MIC Bias

MIC

Baseband

Processor

GPIO

5

Ω

Capacitor

GND