CLASS-D AUDIO AMPLIFIER

Achieve Loud and Clear Sound

While Extending Battery Life

Customer demand is driving the need for louder and clearer speaker

sound in mobile devices. While minimizing impact on battery life,

designers can achieve the performance they require with Fairchild’s

FAB3103. The 2.3W Class-D audio amplifier with integrated boost

regulator and battery automatic gain control (AGC) allows for

high audio output power over a power supply range of 2.5V to 5.2V from a 3.6V

Li-Ion battery.

At low power output, the device’s boost regulator automatically shuts down

for greater efficiency and lower quiescent current consumption, resulting in

longer battery runtime. The FAB3103 audio amplifier also features battery

AGC that reduces gain when the power supply voltage is low in order to limit

maximum power consumption, reducing distortion and preventing early device

software shutdown.

Available in a 12-bump, WLCSP, the FAB3103 device also offers several

protection features including short circuit protection, low voltage shutdown, and

click-and-pop suppression.

Advantages

• LowEMIdesignallows

filterlessoperation

• Highnoiserejectionusing

differentialaudioinputs

• Highefficiencyboostregulator

provideshigheroutputpower

overbatteryvoltages

• Boostshutdownatlower

outputpowerincreases

efficiencyandreduces

quiescentcurrent

consumption

• AGCmonitorsbatteryvoltage

anddynamicallyadjustsgain,

extendingbatteryruntime

Applications

• Mobilehandsets

• Smartphones

• Tablets

• MultimediaInternet

devices(MID)

• Portablemediaplayers

For more information, please visit:

www.fairchildsemi.com/pf/FA/FAB3103.html

Product

Number

Supply

Voltage

(V)

Output

Power

at 10%

THD+N

Output

Power

at 1%

THD+N

THD+N

at 0.1W

Features

Package

(mm x mm)

3.6V,

8Ω (W)

3.6V,

8Ω (W)

3.6V,

8Ω (%)

Speaker

Amplifier

Integrated

Boost

Converter

FAB3103

2.5 to

5.2

2.3

1.85

0.01

Filterless

Class-D

Class-G

12-WLCSP,

1.86 x 1.44

0.01

0.1

1

10

0.001

0.01

0.1

1

10

Output Power (W)

VBATT=4.8V

VBATT=4.2V

VBATT=3.6V

VBATT=2.8V

f = 1KHz

Typical Application Circuit

Class-D Amplifier

OUT+

OUT-

Boost Regulator

VBATT

IN+

IN-

10F

BATTERY

1 F

1 F

EN

SW

22 F

2.2H

AGCT

PVDD

BATTERY

Total Harmonic Distortion + Noise

vs. Output Power