1. FSA8008 Product brief and Sales guide
Oct
Switch&Interface

2. 3.5mm Audio Jack in Cell phone Designs
Growth trend for Cell phone provides to use these two connectors as the only physical interface 2

3. Current Design Challenges
Leakage current
>500uA when MIC is Plugged in
Pop noise
When 3 pole(L/R/GND) headphone jack is attached at Vmic_bias turned on, L or R of Jack touches Vmic_bias first, it triggers Pop noise
Ground
MIC
Ground

4. Design Challenges - Continued
Sensing Audio jack insertion
While Send/End Key is being pressed or when S/E key is stuck, phone only detects a 3 pole jack and does not recover to a 4 pole jack
Accidental re-dialing with plugging in headset while stuck Send/End Key pressed
Software work around to resolve Audio Pop and Stuck S/E key issue
What happens when this button is pressed while insertion ?
4 pole Audio Jack
MIC or Send/End key

5. Fairchild Solution: Headset Detection & Configuration Switch
FSA8008: Headset detection & Configuration Switch
FEATURES
One chip solution for 3- or 4-pole audio jack detection
Provides Send / End key detection & communication
Eliminates Pop &Click noise
No Leakage current
No Software work around needed for stuck button recovery
Space Saving Package
1.4mm x 1.8mm 10ld UMLP
FSA9280A
Cell Phone
Main Board
Baseand
or MAP
GPIO
3-pole Jack
MIC Bias
PMIC
4-pole Jack /w Send /End key
FSA8008
Audio
Codec L R
Mic 5

6. Send / End Key Communication MIC or GND or Send / End Key
Headset detection and configuration Switch – FSA8008
Features
Detection:
Insertion of 3- or 4-pole headset
Pressing of Send/End key
Switch type : MIC (Single Comparator , Normally Open)
VDD : 2.5V ~ 4.4V
VDD : VIO : 1.6V to VDD
THD : 0.01% typical
ESD : 12kV HBM, 15kV IEC
Production Now
Baseband Processor
GPIO1
J_DET
PMIC
MIC BIAS
Audio
CODEC
MIC L R
GPIO2
J_MIC
GPIO3
GPIO4
FSA8008
Detection
& Communication
Detection &
Send / End Key Communication
MIC or GND or Send / End Key 8 5 4 3 2 9 1 6 7
10-Lead UMLP (1.4mm x 1.8mm) 3 4

7. Value Added 10~ 15% Cost saving is expected Total 11.76mm2 Total
Size
FET for detection
2.56mm2
(1.6mm x 1.6mm)
Dual SPDT
3mm2
(3mm x 1mm)
Comparator
1.2mm2
(1.2mm x 1mm)
Passive components
(R,C)
5mm2
(1005 size 8 ∼10EA)
Total
11.76mm2
70% Save
Size
FSA8008
2.52mm2
(1.4mm x 1.8mm)
Capacitor
on power supply
1mm2
(1005 size 2EA)
Total
3.52mm2
10~ 15% Cost saving is expected

8. Other Audio Jack Detection Switches
Fairchild Audio Jack Detection Switches provide single chip solutions for 3- & 4-pole audio jack applications
Key Advantages:
Reduced power consumption
Send/End key detection & communication
Eliminates Pop-n-click noise
Detects multiple headset types
On-chip accessory detection (FSA8008)
Single and dual comparator solutions
71% PCB space reduction vs. discrete solution
Audio Jack Detection Switch Selection Table

9. Sales guide and Product Positioning
Eliminate customer pain, save board space, and reduce BOM in a cost-leadership position.
Background :
Audio jack detection is a brand new category in an emerging application at top-tier cell phone customers. The FSA8008 is designed to detect 3-pole or 4-pole ear jack s with Send/End key, and is the first 3.5mm audio jack product to integrate a comparator, analog switch, and FET. FSC will continue to develop new products that integrate additional circuitry around the audio jack, and is willing to work with any specific customer to consider integrating their particular requirements for this application into a new product.
Secondary target application : Netbook, Tablet, Notebook – which are starting to use single audio/mic sockets that need to detect insertion of 3- or 4-pole jacks
Competitors:
Design support : Demo board is available
MAX14565
I2C interface, Headset Detection, single SPDT(Video/MIC)
FSA8008
GPIO interface, Headset detection(SPST MIC Switch)
MAX14579
GPIO interface, Headset Detection, single SPDT(Video/MIC), Samples in Nov. 2010
FSA8029
Dual comparator w/ single SPDT(Video/MIC)
MAX4855
Dual SPDT with Dual Comparator
FSA8009
Single Comparator w/ single SPDT(Video/MIC)