XX-XXXX; Rev 0; 10/05
12W+12W, Filterless, Spread-Spectrum,
Stereo, Class D Amplifier
General Description
Features
The MAX9741 stereo Class D audio power amplifier
provides Class AB amplifier performance with Class D
efficiency, conserving board space and eliminating the
need for a bulky heatsink. Using a Class D architecture,
it delivers 12W continuous output power into 8Ω loads.
Proprietary and patent-protected modulation and switch-
ing schemes render the traditional Class D EMI suppres-
sion output filter unnecessary.
♦ Filterless Class D Amplifier
♦ Unique Spread-Spectrum Mode Offers 5dB
Emissions Improvement Over Conventional
Methods
♦ Up to 88% Efficient into 16Ω
♦ 12W+12W Continuous Output Power into 8Ω
♦ 15W+15W Continous Output Power into 16Ω
♦ Low 0.07% THD+N
The MAX9741 offers two modulation schemes: a fixed-
frequency mode (FFM), and a spread-spectrum mode
(SSM) that reduces EMI-radiated emissions due to the
modulation frequency. The device utilizes a fully differ-
ential architecture, a full bridged output, and offers
comprehensive click-and-pop suppression.
♦ High PSRR (80dB at 1kHz)
♦ 10V to 25V Single-Supply Operation
♦ Differential Inputs Minimize Common-Mode Noise
♦ Pin-Selectable Gain Reduces Component Count
♦ Industry-Leading Click-and-Pop Suppression
♦ Low Quiescent Current (24mA)
The MAX9741 features high 80dB PSRR, low 0.07%
THD+N, and SNR in excess of 100dB. Short-circuit and
thermal-overload protection prevent the device from
being damaged during a fault condition. The MAX9741
is available in a 56-pin TQFN (8mm x 8mm x 0.8mm)
package. The MAX9741 is specified over the extended
-40°C to +85°C temperature range.
♦ Low-Power Shutdown Mode (0.2µA)
♦ Short-Circuit and Thermal-Overload Protection
Applications
♦ Available in Thermally Efficient, Space-Saving
56-Pin TQFN (8mm x 8mm x 0.8mm) Package
LCD TVs
Hands-Free Car
Phone Adaptors
LCD Monitors
Desktop PCs
LCD Projectors
Ordering Information
Automotive
PKG
CODE
PART
TEMP RANGE PIN-PACKAGE
56 TQFN-EP*
MAX9741ETN+ -40°C to +85°C
T5688-3
+Denotes lead-free package.
*EP = Exposed paddle.
Simplified Block Diagram
INR+
INR-
INL+
INL-
DIFFERENTIAL AUDIO
INPUTS ELIMINATE
NOISE PICKUP
OUTR+
FILTERLESS
CLASS D
GAIN
CONTROL
OUTR-
OUTL+
OUTPUT
PROTECTION
AMPLIFIERS
CLASS D
MODULATOR
DRIVE 2 X 13W
INTO 8Ω LOADS
G1
G2
OUTL-
PROGRAMMABLE
SWITCHING
2
FS1, FS2
MAX9741
FREQUENCY
Pin Configurations appear at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.