MAX9706 Datasheet, PDF (1/25 Pages) Maxim Integrated Products – 3-Channel, 2.3W, Filterless Class D Amplifiers with Active Crossover

19-3681; Rev 0; 12/05
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3-Channel, 2.3W, Filterless Class D Amplifiers
with Active Crossover
General Description
The MAX9706/MAX9707 combine three high-efficiency
Class D amplifiers with an active crossover to provide
stereo highpass outputs, and a mono lowpass output.
All three channels deliver up to 2.3W at 1% THD+N per
channel into 4Ω when operating from a 5V supply.
An internal active filter processes the stereo inputs (left
and right) into stereo highpass and mono lowpass out-
puts. The crossover frequency is pin-selectable to four
different frequencies to accommodate a variety of
speaker configurations. The internal Class D amplifiers
feature low-EMI, spread-spectrum outputs. No output
filters are required.
The MAX9706 features Maxim’s patented DirectDrive™
headphone amplifier, providing ground-referenced
headphone outputs without the need for bulky DC-cou-
pling capacitors. The headphone outputs are capable
of delivering 95mW per channel into 16Ω from a 3.3V
supply, and are protected against ESD up to ±8kV.
The MAX9706/MAX9707 feature pin-programmable
gain, synchronization inputs and outputs, and a shut-
down mode that reduces supply current to less than
1µA. All amplifiers feature click-and-pop suppression
circuitry. Both devices are fully specified over the -40°C
to +85°C extended temperature range and are avail-
able in the thermally enhanced 36-pin (6mm x 6mm x
0.8mm) thin QFN package.
Applications
Notebook Audio Solutions Multimedia Monitors
2.1 Speaker Solutions
Portable DVD Players
Desktop PCs
Table-Top LCD TVs
Features
♦ Triple Class D Amplifiers Deliver 3 x 2.3W into 4Ω
♦ Internal Active Crossover Filter with Adjustable
Crossover Frequency
♦ Low-EMI, Spread-Spectrum Modulation
♦ Low 0.02% THD+N
♦ High PSRR (71dB)
♦ DirectDrive Headphone Amplifier (MAX9706)
♦ Enhanced Click-and-Pop Suppression
♦ Input and Output Modulator Synchronization
♦ Low-Power Shutdown Mode
♦ Up To 90% Efficiency
♦ Space-Saving (6mm x 6mm x 0.8mm) 36-Pin Thin
QFN Package
Ordering Information
PART
MAX9706ETX+
MAX9707ETX+
HP AMP
Yes
No
PIN-PACKAGE
36 Thin QFN
36 Thin QFN
PKG CODE
T3666N-1
T3666N-1
+Denotes lead-free package.
Note: These devices operate over the -40°C to +85°C temper-
ature range.
Functional Diagrams and Pin Configurations appear at end
of data sheet.
Block Diagram
AUDIO IN
MAX9706
FULL-RANGE
TRANSDUCERS
AUDIO IN
MAX9707
FULL-RANGE
TRANSDUCERS
FREQUENCY
SELECT
SHDN
LOW-FREQUENCY
TRANSDUCER
HEADPHONE
FREQUENCY
SELECT
SHDN
LOW-FREQUENCY
TRANSDUCER
________________________________________________________________ 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.