MAX9705 19-3405 Rev 3 5/09 2.3W, Ultra-Low-EMI, Filterless, Class D Audio Amplifier General Description Features Filterless Amplifier Passes FCC-Radiated The MAX9705 3rd-generation, ultra-low EMI, mono, Class Emissions Standards with 24in of Cable D audio power amplifier provides Class AB performance with Class D efficiency. The MAX9705 delivers 2.3W into Unique Spread-Spectrum Mode and Active a 4 load and offers efficiencies above 85%. Active Emissions Limiting (AEL) Achieves Better than 20dB Margin Under FCC Limits emissions limiting (AEL) circuitry greatly reduces EMI by actively controlling the output FET gate transitions under Zero Dead Time (ZDT) H-Bridge Maintains State- all possible transient output-voltage conditions. AEL pre- of-the-Art Efficiency and THD+N vents high-frequency emissions resulting from conven- Simple Master-Slave Setup for Stereo Operation tional Class D free-wheeling behavior in the presence of Up to 90% Efficiency an inductive load. Zero dead time (ZDT) technology 2.3W into 4 (1% THD+N) maintains state-of-the-art efficiency and THD+N perfor- Low 0.02% THD+N (P = 1W, V = 5.0V) OUT DD mance by allowing the output FETs to switch simultane- High PSRR (75dB at 217Hz) ously without cross-conduction. A spread-spectrum modulation scheme eliminates the need for output filter- Integrated Click-and-Pop Suppression ing found in traditional Class D devices. These design Low Quiescent Current (5.4mA) concepts reduce an applications component count and Low-Power Shutdown Mode (0.3A) extend battery life. Short-Circuit and Thermal-Overload Protection The MAX9705 offers two modulation schemes: a fixed- Available in Thermally Efficient, Space-Saving frequency (FFM) mode and a spread-spectrum (SSM) Packages mode that further reduces EMI-radiated emissions due to 10-Pin TDFN (3mm x 3mm x 0.8mm) the modulation frequency. The MAX9705 oscillator can 12-Bump UCSP (1.5mm x 2mm x 0.6mm) be synchronized to an external clock through the SYNC Pin-for-Pin Compatible with the MAX9700 and input, allowing the switching frequency to be externally MAX9712 defined. The SYNC input also allows multiple MAX9705s to be cascaded and frequency locked, minimizing inter- ference due to clock intermodulation. The device utilizes Ordering Information a fully differential architecture, a full-bridged output, and PIN- TOP comprehensive click-and-pop suppression. The gain of PART TEMP RANGE PACKAGE MARK the MAX9705 is set internally (MAX9705A: 6dB, o o MAX9705B: 12dB, MAX9705C: 15.6dB, MAX9705D: MAX9705AETB+T -40 C to +85 C 10 TDFN ACY 20dB), further reducing external component count. o o MAX9705AEBC+T -40 C to +85 C 12 UCSP ACH o o The MAX9705 is available in 10-pin TDFN (3mm x 3mm x MAX9705BETB+T -40 C to +85 C 10 TDFN ACX 0.8mm), and 12-bump UCSP (1.5mm x 2mm x 0.6mm) o o MAX9705BEBC+T -40 C to +85 C 12 UCSP ACG packages. The MAX9705 is specified over the extended Ordering Information continued at end of data sheet. -40C to +85C temperature range. +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. Applications EMI Spectrum Diagram Cellular Phones MP3 Players PDAs Portable Audio 50.0 45.0 40.0 FCC EMI LIMIT 35.0 30.0 25.0 20.0 15.0 Selector Guide appears at end of data sheet. MAXIM S NEW ULTRA-LOW 10.0 OUTPUT SPECTRUM 5.0 30.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 UCSP is a trademark of Maxim Integrated Products, Inc. FREQUENCY (MHz) Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim s website at www.maxim-ic.com. EVALUATION KIT AVAILABLE AMPLITUDE (dBV/m)2.3W, Ultra-Low-EMI, Filterless, Class D Audio Amplifier ABSOLUTE MAXIMUM RATINGS V to GND..............................................................................6V Continuous Power Dissipation (T = +70C) DD A PV to PGND .........................................................................6V 10-Pin TDFN (derate 24.4mW/C above +70C) .....1951.2mW DD GND to PGND .......................................................-0.3V to +0.3V 12-Bump UCSP (derate 6.1mW/C above +70C)........484mW PV to V ..........................................................-0.3V to +0.3V Junction Temperature......................................................+150C DD DD All Other Pins to GND.................................-0.3V to (V + 0.3V) Operating Temperature Range ...........................-40C to +85C DD Continuous Current Into/Out of PV /PGND/OUT ........600mA Storage Temperature Range .............................-65C to +150C DD Continuous Input Current (all other pins) .........................20mA Lead Temperature (soldering, 10s) .................................+300C Duration of OUT Short Circuit to GND or PV ........Continuous Bump Temperature (soldering) DD Duration of Short Circuit Between OUT+ and OUT-.....Continuous Reflow ..........................................................................+235C 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 (V = PV = V = 3.3V, V = V = 0, SYNC = GND (FFM), R = , R connected between OUT+ and OUT-, DD DD SHDN GND PGND L L T = T to T , unless otherwise noted. Typical values are at T = +25C.) (Notes 1, 2) A MIN MAX A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS GENERAL Supply Voltage Range V Inferred from PSRR test 2.5 5.5 V DD Quiescent Current I 5.4 7 mA DD Shutdown Current I 0.3 10 A SHDN Turn-On Time t 30 ms ON Input Resistance R T = +25C 12 20 k IN A MAX9705A 0.88 1.0 1.12 MAX9705B 0.73 0.83 0.93 Input Bias Voltage V Either input V BIAS MAX9705C 0.61 0.71 0.81 MAX9705D 0.48 0.56 0.64 MAX9705A 1.9 2.0 2.1 MAX9705B 3.8 4.0 4.2 Voltage Gain A V/V V MAX9705C 5.7 6.0 6.3 MAX9705D 9.5 10 10.5 Output Offset Voltage V T = +25C 10 69 mV OS A Common-Mode Rejection Ratio CMRR f = 1kHz, input referred 56 dB IN V = 2.5V to 5.5V, T = +25C 50 75 DD A Power-Supply Rejection Ratio PSRR dB f = 217Hz 75 RIPPLE (Note 3) 200mV ripple P-P f = 20kHz 60 RIPPLE R = 8 600 L THD+N = 1%, R = 4 L Output Power P mW OUT f = 1kHz IN MAX9705 ETB+T and 950 MAX9705 EUB+ only R = 8 , L 0.02 Total Harmonic Distortion f = 1kHz, either P = 450mW IN OUT THD+N % Plus Noise FFM or SSM R = 4 , L 0.025 P = 375mW OUT Peak voltage, Into shutdown -68 Click/Pop Level K A-weighted dB CP Out of shutdown -60.5 (Notes 3, 4) Output Slew Rate SR 176 V/s 2 MAX9705