19-3887; Rev 0; 2/06
12W+12W, Low-EMI, 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 high-efficiency Class
D architecture, it delivers 12W continuous output power
into 8Ω loads. Proprietary modulation and switching
schemes render the traditional Class D EMI suppression
output filter unnecessary.
♦ Low-EMI Class D Amplifier
♦ Spread-Spectrum Mode Reduces EMI
♦ Passes FCC EMI Limits with Ferrite Bead Filters
with 0.5m Cables
♦ 12W+12W Continuous Output Power into 8Ω
♦ Low 0.1% THD+N
The MAX9741 offers two modulation schemes: a fixed-fre-
quency mode (FFM), and a spread-spectrum mode (SSM)
that reduces EMI-radiated emissions. The device utilizes a
fully differential 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
♦ Short-Circuit and Thermal-Overload Protection
The MAX9741 features high 80dB PSRR, low 0.1%
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.
♦ Available in Thermally Efficient, Space-Saving
56-Pin TQFN (8mm x 8mm x 0.8mm) Package
Applications
Ordering Information
PKG
CODE
T5688-3
LCD/PDP TVs
CRT TVs
PART
TEMP RANGE PIN-PACKAGE
56 TQFN-EP*
MAX9741ETN+ -40°C to +85°C
PC Speakers
+Denotes lead-free package.
*EP = Exposed paddle.
Simplified Block Diagram
INR+
INR-
INL+
INL-
DIFFERENTIAL AUDIO
INPUTS ELIMINATE
NOISE PICKUP
CLASS D
GAIN
CONTROL
OUTPUT
PROTECTION
AMPLIFIERS
DRIVE 2 X 12W
INTO 8Ω LOADS
CLASS D
MODULATOR
G1
G2
PROGRAMMABLE
SWITCHING
2
FS1, FS2
MAX9741
FREQUENCY
Pin Configuration appears 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.