Document
19-3681; Rev 0; 12/05
KIT ATION EVALU E L B AVAILA
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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 outputs. 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-coupling 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 shutdown 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 available in the thermally enhanced 36-pin (6mm x 6mm x 0.8mm) thin QFN package.
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
MAX9706/MAX9707
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 temperature range. Functional Diagrams and Pin Configurations appear at end of data sheet.
Applications
Notebook Audio Solutions 2.1 Speaker Solutions Desktop PCs Multimedia Monitors Portable DVD Players Table-Top LCD TVs
Block Diagram
MAX9706 MAX9707
FULL-RANGE TRANSDUCERS AUDIO IN
AUDIO IN
FULL-RANGE TRANSDUCERS
LOW-FREQUENCY TRANSDUCER FREQUENCY SELECT HEADPHONE
LOW-FREQUENCY TRANSDUCER FREQUENCY SELECT SHDN
SHDN
________________________________________________________________ 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.
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3-Channel, 2.3W, Filterless Class D Amplifiers with Active Crossover MAX9706/MAX9707
ABSOLUTE MAXIMUM RATINGS
VDD, PVDD, HPVDD, CPVDD to GND ........................-0.3V to +6V GND to PGND, CPGND.........................................-0.3V to +0.3V CPVSS, VSS to GND..................................................-6V to +0.3V C1N to GND ...........................................(CPVSS - 0.3V) to +0.3V C1P to GND ...........................................-0.3V to (CPVDD + 0.3V) HPL, HPR.....................................................................-3V to +3V All Other Pins to GND.................................-0.3V to (VDD + 0.3V) OUT_+, OUT_ -, Short Circuit to GND or PVDD ...........Continuous OUT_+ Short Circuit to OUT_-....................................Continuous HPR, HPL Short Circuit to GND..................................Continuous MONO_OUT Short Circuit to GND or VDD ....................Continuous Continuous Current (PVDD, OUT_+, OUT_-, PGND).............1.7A Continuous Current (MONO_OUT, CPVDD, C1N, C1P, CPGND, CPVSS, VSS, HPVDD, HPR, HPL) ......................0.85A Continuous Current (all other pins) .....................................20mA Continuous Power Dissipation (TA = +70°C) Single-Layer Board 36-Pin TQFN (derate 26.3mW/°C above +70°C) .......2105mW Multilayer Board 36-Pin TQFN (derate 35.7mW/°C above +70°C) .......2857mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Junction Temperature ......................................................+150°C Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VDD = PVDD = HPVDD = 5V, GND = PGND = CPGND = 0V, SHDN = VDD, GAIN1 = GAI.