19-0606; Rev 3; 9/09 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Features The MAX9789/MAX9790 combine a stereo, 2W Class AB speaker power amplifier with a stereo 100mW DirectDrive® headphone amplifier in a single device. The MAX9789/MAX9790 are designed for use with the Microsoft Windows Vista® operating system and are fully compliant with Microsoft’s Windows Vista specifications. The headphone amplifier features Maxim’s patented† DirectDrive architecture that produces a ground-referenced output from a single supply to eliminate the need for large DC-blocking capacitors, as well as save cost, board space, and component height. A high +90dB PSRR and low 0.002% THD+N ensures clean, low-distortion amplification of the audio signal. Separate speaker and headphone amplifier control inputs provide independent shutdown of the speaker and headphone amplifiers, allowing speaker and headphone amplifiers to be active simultaneously, if required. The industry-leading click-and-pop suppression circuitry reduces audible transients during startup and shutdown cycles. o Microsoft Windows Vista Compliant o Class AB 2W Stereo BTL Speaker Amplifier o 100mW DirectDrive Headphone Amplifier Eliminates Costly, Bulky DC-Blocking Capacitors o Excellent RF Immunity o Integrated 120mA LDO (MAX9789) o High +90dB PSRR, Low 0.002% THD+N o Low-Power Shutdown Mode o Click-and-Pop Suppression o Short-Circuit and Thermal-Overload Protection o Available in 32-Pin Thin QFN (5mm x 5mm x 0.8mm) Package MAX9789BETJ+** 32 TQFN-EP* Yes 25 The MAX9789 features an internal LDO that can be used as a clean power supply for a CODEC or other circuits. The LDO output voltage is set internally at 4.75V or can be adjusted between 1.21V and 4.75V using a simple resistive divider. The LDO is protected against thermal overloads and short circuits while providing 120mA of continuous output current and can be enabled independently of the audio amplifiers. MAX9789CETJ+ 32 TQFN-EP* Yes 100 MAX9790AETJ+ 32 TQFN-EP* No 100 By disabling the speaker and headphone amplifiers, and the LDO (for MAX9789), the MAX9789/MAX9790 enter low-power shutdown mode and draw only 0.3µA. The MAX9789/MAX9790 operate from a single 4.5V to 5.5V supply and feature thermal-overload and output short-circuit protection. Devices are specified over the -40°C to +85°C extended temperature range. Applications Notebook Computers Ordering Information PART PIN-PACKAGE INTERNAL LDO tON (ms) MAX9789AETJ+ 32 TQFN-EP* Yes 100 MAX9790BETJ+** 32 TQFN-EP* No 25 Note: All devices are specified over the -40°C to +85°C extended temperature range. +Denotes a lead-free/RoHS-compliant package. *EP = Exposed pad. **Future product—contact factory for availability. Simplified Block Diagrams SPEAKER SUPPLY 4.5V TO 5.5V HEADPHONE SUPPLY 3.0V TO 5.5V SPKR_INR MAX9789 SPKR_INL HP_INR Tablet PCs Portable Multimedia Players HP_INL SPKR_EN Pin Configurations appear at end of data sheet. HP_EN MUTE †U.S. Patent # 7,061,327. Windows Vista is a registered trademark of Microsoft Corp. DirectDrive is a registered trademark of Maxim Integrated Products, Inc. GAIN1 GAIN2 4.5V TO 5.5V LDO 1.21V TO 4.75V Simplified Block Diagrams continued at end of data sheet. ________________________________________________________________ Maxim Integrated Products 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. 1 MAX9789/MAX9790 General Description MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers ABSOLUTE MAXIMUM RATINGS Supply Voltage (VDD, PVDD, HPVDD, CPVDD to GND) ..................................................-0.3V to +6.0V GND to PGND, CPGND ......................................................±0.3V CPVSS, C1N, VSS to GND......................................-6.0V to +0.3V HPR, HPL to GND ...............................................................±3.0V Any Other Pin .............................................-0.3V to (VDD + 0.3V) Duration of OUT_+, OUT_- Short Circuit to GND or PVDD ......................................................Continuous Duration of Short Circuit between OUT_+, OUT_and LDO_OUT.........................................................Continuous Duration of Short Circuit between HPR, HPL and GND, VSS or HPVDD ..........................................................Continuous Continuous Current (PVDD, OUT_+, OUT_-, PGND).............1.7A Continuous Current (CPVDD, C1N, C1P, CPVSS, PVSS, VDD, HPVDD, LDO_OUT, HPR, HPL) .............................850mA Continuous Input Current (all other pins) .........................±20mA Continuous Power Dissipation (TA = +70°C) 32-Pin Thin QFN Single-Layer Board (derate 18.6mW/°C above +70°C) ..............................1489mW θJA ...........................................................................53.7°C/W θJC ...........................................................................19.9°C/W 32-Pin Thin QFN Multilayer Board (derate 24.9 mW/°C above +70°C) .............................1990mW θJA ...........................................................................40.2°C/W θJC ...........................................................................19.9°C/W Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7 using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. 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 = CPVDD = HPVDD = HP_EN = VLDO_EN (MAX9789 only) = +5V, VGND = VPGND = VCPGND = SPKR_EN = VLDO_SET (MAX9789 only) = 0V, ILDO_OUT (MAX9789 only) = 0, C1 = C2 = CBIAS = 1µF. RL = ∞, unless otherwise specified, VGAIN1 = 0, VGAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS GENERAL Supply Voltage Headphone Supply Voltage VDD, PVDD CPVDD, HPVDD Guaranteed by PSRR and LDO Line Regulation Tests 4.5 5.5 V Guaranteed by PSRR Test 3.0 5.5 V SPKR_EN Quiescent Current IDD Shutdown Current ISHDN Bias Voltage VBIAS Shutdown to Full Operation tSON Gain Switching Time tSW HP_EN 1 (MAX9789) 0 (MAX9789) 0.1 0.4 mA 1 (MAX9790) 0 (MAX9790) 0.3 6 µA 1 1 7 13 0 0 14 29 0 1 18 40 0.3 6 µA 1.8 1.9 V SPKR_EN = VDD, HP_EN = LDO_EN = GND 1.7 MAX9789A/MAX9789C/MAX9790A 100 MAX9789B/MAX9790B 25 Channel-to-Channel Gain Tracking mA ms 10 µs ±0.1 dB SPEAKER AMPLIFIER Output Power Total Harmonic Distortion Plus Noise 2 POUT THD+N THD+N = 1%, f = 1kHz, TA = +25°C RL = 4Ω 2 RL = 8Ω 1 RL = 8Ω, POUT = 1W, f = 1kHz 0.002 RL = 4Ω, POUT = 1W, f = 1kHz 0.004 _______________________________________________________________________________________ W % Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers (VDD = PVDD = CPVDD = HPVDD = HP_EN = VLDO_EN (MAX9789 only) = +5V, VGND = VPGND = VCPGND = SPKR_EN = VLDO_SET (MAX9789 only) = 0V, ILDO_OUT (MAX9789 only) = 0, C1 = C2 = CBIAS = 1µF. RL = ∞, unless otherwise specified, VGAIN1 = 0, VGAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS VDD = 4.5V to 5.5V, TA = +25°C Power-Supply Rejection Ratio PSRR f = 1kHz, 200mVP-P (Note 4) AV TYP 72 90 MAX UNITS dB 70 f = 10kHz, 200mVP-P (Note 4) Voltage Gain MIN 50 GAIN1 GAIN2 0 0 0 1 10 1 0 15.6 1 1 21.6 6 dB Measured at speaker amplifier inputs Input Impedance RIN Output Offset Voltage Click-and-Pop Level Signal-to-Noise Ratio VOS KCP GAIN1 GAIN2 0 0 80 0 1 65 1 0 45 1 1 25 Measured between OUT_+ and OUT_-, TA = +25°C kΩ ±1 ±15 ±1 ±25 mV MAX9789C RL = 8Ω, peak voltage, Into shutdown A-weighted, 32 samples per second (Notes 3, 4) Out of shutdown -50 dBV -50 A-weighted 102 f = 22Hz to 22kHz 99 SNR RL = 8Ω, POUT = 1W Noise Vn BW = 22Hz to 22kHz 30 µVRMS Capacitive-Load Drive CL No sustained oscillations 200 pF L to R, R to L, RL = 8Ω, FS = 0.707VRMS, VOUT = 70.7nVRMS, 20kHz AES17, BW = 20Hz to 20kHz -70 dB 1.4 V/µs Crosstalk Slew Rate SR dB HEADPHONE AMPLIFIER Output Power POUT Total Harmonic Distortion Plus Noise THD+N THD+N = 1%, f = 1kHz, TA = +25°C RL = 16Ω 100 RL = 32Ω 55 mW RL = 32Ω, FS = 0.300VRMS, VOUT = 210mVRMS, 20kHz AES17, BW = 20Hz to 20kHz -77 dB FS RL = 32Ω, POUT = 40mW, f = 1kHz 0.02 % RL = 16Ω, POUT = 60mW, f = 1kHz 0.03 RL = 10kΩ, FS = 0.707VRMS, VOUT = 500mVRMS, 20kHz AES17, BW = 20Hz to 20kHz -94 dB FS _______________________________________________________________________________________ 3 MAX9789/MAX9790 ELECTRICAL CHARACTERISTICS (continued) MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers ELECTRICAL CHARACTERISTICS (continued) (VDD = PVDD = CPVDD = HPVDD = HP_EN = VLDO_EN (MAX9789 only) = +5V, VGND = VPGND = VCPGND = SPKR_EN = VLDO_SET (MAX9789 only) = 0V, ILDO_OUT (MAX9789 only) = 0, C1 = C2 = CBIAS = 1µF. RL = ∞, unless otherwise specified, VGAIN1 = 0, VGAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS HPVDD = 3V to 5.5V, TA = +25°C Power-Supply Rejection Ratio PSRR 84 AV Measured at headphone amplifier inputs Output Offset Voltage VOS TA = +25°C Click-and-Pop Level KCP SNR RL = 32Ω, f = 1kHz, A-weighted, FS = 0.300VRMS, VOUT = 300µVRMS 89 RL = 10kΩ, f = 1kHz, A-weighted, FS = 0.707VRMS, VOUT = 707µVRMS 97 RL = 32Ω, POUT = 60mW dB L to R, R to L, 20kHz AES17 BW = 20Hz to 20kHz kΩ mV dB FS 100 103 No sustained oscillations dB 80 ±7 ±10 dBV A-weighted CL UNITS -60 22Hz to 22kHz Capacitive-Load Drive dB 12 µVRMS 200 pF RL = 32Ω, FS = 0.300VRMS, VOUT = 30mVRMS -74 RL = 10kΩ, FS = 0.707VRMS, VOUT = 70.7mVRMS -77 dB SR fOSC 40 ±2 ±2 -60 BW = 22Hz to 22kHz Charge-Pump Frequency 20 MAX9789C RL = 32Ω, peak voltage, Into shutdown A-weighted, 32 samples per second (Notes 3, 4) Out of shutdown Vn Slew Rate MAX 3.5 Noise Crosstalk 95 63 RIN Signal-to-Noise Ratio 70 f = 10kHz, VRIPPLE = 200mVP-P (Note 4) Input Impedance DR TYP f = 1kHz, VRIPPLE = 200mVP-P (Note 4) Voltage Gain Dynamic Range MIN 500 0.4 550 625 V/µs MAX9789C 475 550 625 Inferred from line regulation 4.5 IOUT = 0mA 0.1 0.4 IOUT = 120mA -40 kHz LOW-DROPOUT LINEAR REGULATOR Regulator Input Voltage Range VDD Ground Current IGND Output Current IOUT 120 Crosstalk VOUT = 4.75V, IOUT = 0mA, f = 1kHz, speaker POUT = 2W, speaker RL = 4Ω Fixed Output Voltage Accuracy IOUT = 1mA Adjustable Output Voltage Range LDO_SET Reference Voltage LDO_SET Dual-Mode Threshold 4 VSET 5.5 MAX9789C -95 1.21 1.18 1.18 1.21 1.21 200 _______________________________________________________________________________________ mA mA dB ±1.5 ±3.0 MAX9789C V 4.75 1.23 1.25 % V V mV Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers (VDD = PVDD = CPVDD = HPVDD = HP_EN = VLDO_EN (MAX9789 only) = +5V, VGND = VPGND = VCPGND = SPKR_EN = VLDO_SET (MAX9789 only) = 0V, ILDO_OUT (MAX9789 only) = 0, C1 = C2 = CBIAS = 1µF. RL = ∞, unless otherwise specified, VGAIN1 = 0, VGAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL LDO_SET Input Bias Current (Note 5) ISET Dropout Voltage (Note 6) VDO Current Limit CONDITIONS VOUT = 4.75V (fixed output operation), TA = +25°C MIN TYP MAX UNITS ±20 ±500 nA IOUT = 50mA 25 50 IOUT = 120mA 75 150 mV ILIM Startup Time Line Regulation VIN = 4.5V to 5.5V, LDO_OUT = 2.5V, ILDO_OUT = 1mA Load Regulation VLDO_OUT = 4.75V, 1mA < ILDO_OUT < 120mA Ripple Rejection VRIPPLE = 200mVP-P ILDO_OUT = 10mA Output Voltage Noise -4.8 300 mA 20 µs +0.8 +4.8 0.2 f = 1kHz 59 f = 10kHz 42 20Hz to 22kHz, CLDO_OUT = 2 x 1µF, ILDO_OUT = 120mA 125 mV/V mV/mA dB µVRMS DIGITAL INPUTS (SPKR_EN, HP_EN, MUTE, GAIN1, GAIN2, LDO_EN (MAX9789 Only)) Input-Voltage High VINH Input-Voltage Low VINL Input Bias Current 2 V 0.8 V ±1 µA Note 2: All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design. Note 3: Specified at room temperature with an 8Ω resistive load connected across BTL output for speaker amplifier. Specified at room temperature with a 32Ω resistive load connected between HPR, HPL, and GND for headphone amplifier. Speaker and headphone mode transitions are controlled by SPKR_EN and HP_EN control pins, respectively. Note 4: Amplifier inputs AC-coupled to GND. Note 5: Maximum value is due to test limitations. Note 6: VLDO_OUT = VLDO_OUTNOMINAL - 2%. _______________________________________________________________________________________ 5 MAX9789/MAX9790 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25°C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.) -80 -90 MAX9789 toc03 10 RL = 10kΩ 1 -80 fIN = 20Hz 0.1 fIN = 10kHz 0.01 -90 -100 fIN = 1kHz 0.001 -100 100 1k 10k 100k 10 100 1k 10k FREQUENCY (Hz) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT VOLTAGE (HEADPHONE MODE) CROSSTALK vs. FREQUENCY (HEADPHONE MODE) 0 MAX9789 toc04 -20 CROSSTALK (dB) 1 fIN = 20Hz 0.1 fIN = 10kHz FS = 0.707VRMS VOUT = -20dB FS RL = 10kΩ -10 -30 -40 -50 LEFT TO RIGHT -60 -70 0.01 -80 fIN = 1kHz -90 0.001 RIGHT TO LEFT -100 0 0.5 1.0 1.5 2.0 10 100 1k 1.0 1.5 2.0 HEADPHONE OUTPUT SPECTRUM CROSSTALK (dB) HPVDD = 3V RL = 10kΩ 0.5 OUTPUT VOLTAGE (VRMS) FREQUENCY (Hz) 10 0 100k 10k 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 FS = 0.300VRMS VOUT = -60dB FS RL = 10kΩ 0 100k 5k 10k 15k MAX9789 toc06 10 MAX9789 toc05 -110 20k OUTPUT VOLTAGE (VRMS) FREQUENCY (Hz) FREQUENCY (Hz) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (SPEAKER MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (SPEAKER MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (SPEAKER MODE) VOUT = -3dB FS -80 -80 -75 VOUT = -3dB FS MAX9789 toc09 -75 MAX9789 toc07 -75 MAX9789 toc08 THD+N (%) HPVDD = 3V FS = 0.707VRMS VOUT = -3dB FS RL = 10kΩ -70 THD+N (dB FS) THD+N (dB FS) -70 -60 THD+N (%) FS = 0.707VRMS VOUT = -3dB FS RL = 10kΩ MAX9789 toc01 -60 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT VOLTAGE (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) MAX9789 toc02 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) VOUT = -3dB FS -80 -85 -90 THD+N (dB FS) THD+N (dB FS) -85 THD+N (dB FS) MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers -85 -90 -90 -95 -100 -95 -95 FS = 0.707VRMS RL = 3Ω -100 -100 10 100 1k FREQUENCY (Hz) 6 10k 100k -105 FS = 0.707VRMS RL = 4Ω 10 100 FS = 0.707VRMS RL = 8Ω -110 1k FREQUENCY (Hz) 10k 100k 10 100 1k FREQUENCY (Hz) _______________________________________________________________________________________ 10k 100k Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers RL = 3Ω 10 fIN = 10kHz 0.1 THD+N (%) 0.1 RL = 8Ω 1 1 THD+N (%) THD+N (%) 1 RL = 4Ω MAX9789 toc12 10 MAX9789 toc10 10 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (SPEAKER MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (SPEAKER MODE) MAX9789 toc11 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (SPEAKER MODE) fIN = 10kHz 0.1 fIN = 10kHz fIN = 20Hz fIN = 1kHz 0.01 fIN = 1kHz 0.001 fIN = 20Hz 0.001 0.5 1.0 1.5 2.0 2.5 3.0 0.5 1.0 1.5 2.0 0.001 0 2.5 0.5 1.0 1.5 OUTPUT POWER (W) OUTPUT POWER (W) OUTPUT POWER (W) CROSSTALK vs. FREQUENCY (SPEAKER MODE) SPEAKER OUTPUT SPECTRUM OUTPUT POWER vs. LOAD RESISTANCE (SPEAKER MODE) CROSSTALK (dB) -30 -40 -50 LEFT TO RIGHT RIGHT TO LEFT -70 -80 -90 -100 10 100 1k 10k 100k FS = 0.707VRMS VOUT = -60dB FS RL = 8Ω THD+N = 10% 2.0 1.5 1.0 0 0 5k 10k 15k FREQUENCY (Hz) 20k 1 10 RL (Ω) 100 POWER-SUPPLY REJECTION RATIO (SPEAKER MODE) 0 MAX9789 toc16 VRIPPLE = 200mVP-P OUTPUT REFERRED -10 -20 -30 1.00 PSRR (dB) POWER DISSIPATION PER CHANNEL (W) 1.25 2.5 THD+N = 1% POWER DISSIPATION PER CHANNEL vs. OUTPUT POWER (SPEAKER MODE) fIN = 1kHz fIN = 1kHz 3.0 0.5 FREQUENCY (Hz) 1.50 3.5 MAX9789 toc17 -20 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 OUTPUT POWER (W) FS = 0.707VRMS VOUT = -20dB FS RL = 8Ω MAX9789 toc14 0 -10 -60 0 MAX9789 toc13 0 fIN = 1kHz MAX9789 toc15 fIN = 20Hz CROSSTALK (dB) 0.01 0.01 RL = 4Ω 0.75 0.50 -40 -50 -60 -70 -80 RL = 8Ω 0.25 -90 0 100 0 0.5 1.0 1.5 OUTPUT POWER PER CHANNEL (W) 2.0 10 100 1k 10k FREQUENCY (Hz) 100k _______________________________________________________________________________________ 7 MAX9789/MAX9790 Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25°C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.) Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25°C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.) SPEAKER STARTUP WAVEFORM SPEAKER STARTUP WAVEFORM MAX9789 toc18 MAX9789 toc19 MAX9789B/MAX9790B MAX9789A/MAX9789C/MAX9790A SPKR_EN 5V/div SPKR_EN 5V/div OUT_+ AND OUT_2V/div OUT_+ AND OUT_2V/div OUT_+ - OUT_100mV/div OUT_+ - OUT_100mV/div 20ms/div 20ms/div TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) SPEAKER SHUTDOWN WAVEFORM MAX9789 toc20 SPKR_EN 5V/div -70 OUT_+ AND OUT_2V/div -80 MAX9789 toc21 -65 THD+N (dB FS) -75 VOUT = -3dB FS -85 -90 -95 OUT_+ - OUT_100mV/div -100 FS = 0.300VRMS RL = 32Ω -105 -110 20ms/div 10 100 1k 10k 100k FREQUENCY (Hz) -80 -85 -90 -70 -75 VOUT = -3dB FS -80 -85 -90 -85 -90 -95 -95 -100 -100 -100 HPVDD = 3V FS = 0.300VRMS RL = 32Ω -110 10 100 FS = 0.300VRMS RL = 16Ω -105 -110 1k FREQUENCY (Hz) 10k 100k 10 100 VOUT = -3dB FS -80 -95 -105 MAX9789 toc24 -75 THD+N (dB FS) VOUT = -3dB FS -70 THD+N (dB FS) -75 -65 MAX9789 toc23 -70 8 -65 MAX9789 toc22 -65 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) THD+N (dB FS) MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers HPVDD = 3V FS = 0.300VRMS RL = 16Ω -105 -110 1k FREQUENCY (Hz) 10k 100k 10 100 1k FREQUENCY (Hz) _______________________________________________________________________________________ 10k 100k Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789 toc27 10 MAX9789 toc26 10 MAX9789 toc25 10 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE) f = 10kHz 50 100 150 0.1 f = 20Hz RL = 32Ω 0.01 20 0 200 40 60 80 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE) CROSSTALK vs. FREQUENCY (HEADPHONE MODE) MAX9789 toc28 0 0.1 f = 1kHz AMPLITUDE (dB) CROSSTALK (dB) THD+N (%) f = 20Hz -40 -50 -60 LEFT TO RIGHT -70 -80 -90 HPVDD = 3V RL = 32Ω 0.01 40 60 80 RIGHT TO LEFT -110 100 10 100 OUTPUT POWER (mW) 1k 100k 10k 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 0 5 15 20 OUTPUT POWER vs. LOAD RESISTANCE (HEADPHONE MODE) 100 HPVDD = 3V fIN = 1kHz OUTPUT POWER (mW) fIN = 1kHz 10 FREQUENCY (kHz) OUTPUT POWER vs. LOAD RESISTANCE (HEADPHONE MODE) 150 150 FS = 0.707VRMS VOUT = -60dB FS RL = 32Ω FREQUENCY (Hz) MAX9789 toc31 20 OUTPUT POWER (mW) 0 -100 100 HEADPHONE OUTPUT SPECTRUM -30 f = 10kHz 1 FS = 0.300VRMS VOUT = -20dB FS RL = 32Ω -20 50 0 OUTPUT POWER (mW) OUTPUT POWER (mW) -10 HPVDD = 3V RL = 16Ω 0.01 100 OUTPUT POWER (mW) 10 f = 1kHz MAX9789 toc30 0.01 f = 20Hz 100 THD+N = 10% 50 MAX9789 toc32 RL = 16Ω 0 f = 1kHz 0.1 f = 1kHz 1 THD+N (%) THD+N (%) THD+N (%) f = 20Hz 0.1 f = 10kHz 1 MAX9789 toc29 f = 10kHz 1 THD+N = 10% 50 THD+N = 1% THD+N = 1% 0 0 10 100 RL (Ω) 1000 10 100 RL (Ω) 1000 _______________________________________________________________________________________ 9 MAX9789/MAX9790 Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25°C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.) Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25°C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.) POWER DISSIPATION vs. OUTPUT POWER (HEADPHONE MODE) RL = 16Ω RL = 32Ω 50 25 0 125 MAX9789 toc34 275 250 225 200 175 150 125 100 75 POWER DISSIPATION PER CHANNEL vs. OUTPUT POWER (HEADPHONE MODE) POWER DISSIPATION PER CHANNEL (mW) MAX9789 toc33 HPVDD = 3V 100 75 RL = 16Ω 50 RL = 32Ω 25 0 0 25 50 75 100 OUTPUT POWER PER CHANNEL (mW) 125 0 20 40 60 OUTPUT POWER PER CHANNEL (mW) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (HEADPHONE MODE) HEADPHONE OUTPUT POWER vs. HPVDD 0 MAX9789 toc35 125 100 VRIPPLE = 200mVP-P OUTPUT REFERRED -10 -20 -30 RL = 16Ω PSRR (dB) 75 50 -40 -50 -60 -70 RL = 32Ω 25 -80 THD+N = 1% fIN = 1kHz -90 -100 0 3.0 3.5 4.0 HPVDD (V) 4.5 5.0 HEADPHONE STARTUP WAVEFORM 10 100 1k 10k FREQUENCY (Hz) MAX9789 toc38 MAX9789B/MAX9790B MAX9789A/MAX9789C/MAX9790A 20ms/div 100k HEADPHONE STARTUP WAVEFORM MAX9789 toc37 10 80 MAX9789 toc36 POWER DISSIPATION PER CHANNEL (mW) 300 HEADPHONE OUTPUT POWER (mW) MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers HP_EN 5V/div HP_EN 5V/div HP_ 500mV/div HP_ 500mV/div 20ms/div ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers HEADPHONE SHUTDOWN WAVEFORM SUPPLY CURRENT vs. SUPPLY VOLTAGE MAX9789 toc39 HP_EN HP_ 500mV/div 15 SUPPLY CURRENT (mA) 5V/div MAX9789 toc40 20 SPKR_EN = 0 HP_EN = 1 10 SPKR_EN = 0 HP_EN = 0 SPKR_EN = 1 HP_EN = 0 5 SPKR_EN = 1 HP_EN = 1 0 -5 20ms/div 4.50 0.1 VLDO_OUT = 4.75V 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 0 4.75 5.00 5.25 SUPPLY VOLTAGE (V) 0 5.50 75 100 ILOAD (mA) 125 0.05 0 -0.05 2.0 LDO OUTPUT VOLTAGE ACCURACY (%) MAX9789 toc43 VLDO_OUT = 4.75V ILDO_OUT = 0A 50 150 LDO OUTPUT VOLTAGE ACCURACY vs. TEMPERATURE LDO OUTPUT VOLTAGE ACCURACY vs. AMPLIFIER OUTPUT POWER 0.10 25 MAX9789 toc44 4.50 LDO OUTPUT VOLTAGE ACCURACY (%) MAX9789 toc42 MAX9789 toc41 0.2 2.0 LDO OUTPUT VOLTAGE ACCURACY (%) SHUTDOWN CURRENT (μA) SPKR_EN = 5V HP_EN = 0 LDO_EN = 0 (MAX9789) 5.50 LDO OUTPUT VOLTAGE ACCURACY vs. ILOAD SHUTDOWN CURRENT vs. SUPPLY VOLTAGE 0.3 4.75 5.00 5.25 SUPPLY VOLTAGE (V) ILDO_OUT = 1mA 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 -0.10 0 0.5 1.0 1.5 2.0 2.5 AMPLIFIER OUTPUT POWER (W) 3.0 -40 -15 10 35 TEMPERATURE (°C) 60 85 ______________________________________________________________________________________ 11 MAX9789/MAX9790 Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25°C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.) Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25°C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.) 60 50 VLDO_OUT = 3.3V 40 30 -30 -40 -60 20 -70 10 -80 0 VLDO_OUT = 4.75V -50 25 50 75 100 150 125 1 0.1 VLDO_OUT = 3.3V 0.01 -90 0 MAX9789 toc47 -20 RIPPLE REJECTION (dB) VLDO_OUT = 4.75V 70 VRIPPLE = 200mVP-P IOUT = 10mA OUTPUT REFERRED -10 10 OUTPUT NOISE (μV√Hz) MAX9789 toc45 90 80 OUTPUT NOISE vs. FREQUENCY RIPPLE REJECTION vs. FREQUENCY 0 MAX9789 toc46 DROPOUT VOLTAGE vs. ILOAD 100 DROPOUT VOLTAGE (mV) 10 ILOAD (mA) 100 1k 10 100k 10k 100 1k 10k FREQUENCY (Hz) FREQUENCY (Hz) LINE-TRANSIENT RESPONSE LDO LOAD-TRANSIENT RESPONSE MAX9789 toc48 MAX9789 toc49 VDD 1V/div 5.5V ILDO_OUT 15mA/div 4.5V LDO_OUT (AC-COUPLED) 20mV/div AC-COUPLED VLDO_OUT 10mV/div 1ms/div 20ms/div LDO SHUTDOWN RESPONSE -20 ILOAD = 0mA VLDO_OUT = 4.75V POUT = 2W RL = 4Ω IOUT = 0mA -30 LDO_EN 2V/div -40 VLDO_OUT 2V/div -50 -60 -70 RIGHT SPEAKER TO LDO -80 -90 -100 -110 200ms/div 12 MAX9789 toc51 LDO CROSSTALK vs. FREQUENCY MAX9789 toc50 CROSSTALK (dB) MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers LEFT SPEAKER TO LDO -120 10 100 1k 10k FREQUENCY (Hz) ______________________________________________________________________________________ 100k 100k Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers PIN NAME FUNCTION MAX9789 MAX9790 1 — LDO_SET 2 2 SPKR_INR Right-Channel Speaker Amplifier Input 3 3 SPKR_INL 4 — LDO_EN 5, 21 5, 21 PGND Power Ground. Star-connect to GND. 6 6 OUTL+ Left-Channel Speaker Amplifier Output, Positive Phase 7 7 OUTL- Left-Channel Speaker Amplifier Output, Negative Phase 8, 18 8, 18 PVDD Speaker Amplifier Power-Supply Input. Bypass with a 0.1µF capacitor to PGND. 9 9 CPVDD 10 10 C1P 11 11 CPGND 12 12 C1N 13 13 CPVSS 14 14 PVSS 15 15 HPR Right-Channel Headphone Amplifier Output 16 16 HPL Left-Channel Headphone Amplifier Output 17 17 HPVDD Headphone Amplifier Positive Power Supply. Connect a 10µF capacitor between HPVDD and PGND. 19 19 OUTR- Right-Channel Speaker Amplifier Output, Negative Phase 20 20 OUTR+ Right-Channel Speaker Amplifier Output, Positive Phase 22 22 HP_EN Active-High Headphone Amplifier Enable 23 23 SPKR_EN 24 24 BIAS Common-Mode Bias Voltage. Bypass with a 1µF capacitor to GND. 25 25 MUTE Active-Low Mute Enable. Mutes speaker and headphone amplifiers. 26 26 HP_INR Right-Channel Headphone Amplifier Input 27 27 HP_INL Left-Channel Headphone Amplifier Input 28 4, 28 GND 29 — LDO_OUT 30 30 VDD 31 31 GAIN1 Speaker Amplifier Gain Select 1 32 32 GAIN2 Speaker Amplifier Gain Select 2 — 1, 29 N.C. EP EP EP Regulator Feedback Input. Connect to GND for 4.75V fixed output. Connect to a resistordivider for adjustable output. See Figure 1. Left-Channel Speaker Amplifier Input LDO Enable. Connect LDO_EN to VDD to enable the LDO. Charge-Pump Power Supply. Connect a 1µF capacitor between CPVDD and PGND. Charge-Pump Flying Capacitor Positive Terminal. Connect a 1µF capacitor between C1P to C1N. Charge-Pump Ground. Connect directly to PGND plane. Charge-Pump Flying Capacitor Negative Terminal. Connect a 1µF capacitor between C1P to C1N. Charge-Pump Output. Connect to PVSS. Headphone Amplifier Negative Power Supply. Connect a 1µF capacitor between PVSS and PGND. Active-Low Speaker Amplifier Enable Signal Ground. Star-connect to PGND. LDO Output. Bypass with two 1µF capacitors to GND. Positive Power Supply and LDO Input (MAX9789). Bypass with one 0.1µF capacitor and two 1µF capacitors to GND (MAX9789). Bypass with one 0.1µF capacitor and one 1µF capacitor to GND (MAX9790). No Connection. Not internally connected. Exposed Paddle. Connect to GND. ______________________________________________________________________________________ 13 MAX9789/MAX9790 Pin Description MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Detailed Description The MAX9789/MAX9790 combine a 2W BTL speaker amplifier with an 100mW DirectDrive headphone amplifier. These devices feature comprehensive click-and-pop suppression and programmable four-level speaker amplifier gain control. The MAX9789/MAX9790 feature high +90dB PSRR, low 0.002% THD+N, industry-leading clickand-pop performance, low-power shutdown mode, and excellent RF immunity. The MAX9789 incorporates an integrated LDO that serves as a clean power supply for a CODEC or other circuits. The MAX9789/MAX9790 is Microsoft Windows Vista compliant. See Table 1 for a comparison of the Microsoft Windows Vista premium mobile specifications and MAX9789/MAX9790 specifications. The speaker amplifiers use BTL architecture, doubling the voltage drive to the speakers and eliminating the need for DC-blocking capacitors. The output consists of two signals, identical in magnitude, but 180° out of phase. The headphone amplifiers use Maxim’s patented DirectDrive architecture to eliminate the bulky output DC-blocking capacitors required by traditional headphone amplifiers. A charge pump inverts a positive supply (CPVDD) to create a negative supply (CPVSS). The headphone amplifiers operate from these bipolar supplies with their outputs biased about GND. The benefit of the GND bias is that the amplifier outputs no longer have a DC component (typically VDD / 2). This feature eliminates the large DC-blocking capacitors required with conventional headphone amplifiers to conserve board space and system cost, as well as improve low-frequency response. The MAX9789/MAX9790 feature programmable speaker amplifier gain, allowing the speaker gain to be set by the logic voltages applied to GAIN1 and GAIN2, while the headphone amplifiers feature a fixed 3.5dB gain. Both amplifiers feature an undervoltage lockout that prevents operation from an insufficient power supply and click-and-pop suppression that eliminates audible transients on startup and shutdown. The amplifiers include thermal overload and short-circuit protection. An additional feature of the speaker amplifiers is that there is no phase inversion from input to output. Low-Dropout Linear Regulator (MAX9789 Only) The MAX9789’s low-dropout (LDO) linear regulator can be used to provide a clean power supply to a CODEC or other circuitry. The LDO can be enabled independently of the audio amplifiers. Set LDO_EN = VDD to enable the LDO or set LDO_EN = GND to disable the LDO. The LDO is capable of providing up to 120mA continuous current and features Maxim’s Dual Mode™ feedback, easily enabling a fixed 4.75V output or a user-adjustable output. When LDO_SET is connected to GND, the output is internally set to 4.75V. The output voltage can be adjusted from 1.21V to 4.75V by connecting two external resistors as a voltage divider, at LDO_SET (Figure 1). Table 1. Windows Premium Mobile Vista Specifications vs. MAX9789/MAX9790 Specifications DEVICE TYPE WINDOWS PREMIUM MOBILE Vista SPECIFICATIONS MAX9789/MAX9790 TYPICAL PERFORMANCE ≤ -65dB FS [20Hz, 20kHz] -94dB FS [20Hz, 20kHz] ≤ -80dB FS, A-weighted ≤ -50dB [20Hz, 20kHz] ≤ -45dB FS [20Hz, 20kHz] -97dB FS, A-weighted -77dB [20Hz, 20kHz] -77dB FS [20Hz, 20kHz] Dynamic range with signal present ≤ -60dB FS, A-weighted -89dB FS, A-weighted Headphone output crosstalk ≤ -50dB [20Hz, 20kHz] -74dB [20Hz, 20kHz] REQUIREMENT THD+N Analog Line Output Jack (RL = 10kΩ, FS = 0.707VRMS) Dynamic range with signal present Line output crosstalk THD+N Analog Headphone Out Jack (RL = 32Ω, FS = 0.300VRMS) Note: THD+N, DYNAMIC RANGE, and CROSSTALK should be measured in accordance with AES-17 audio measurements standards. Dual Mode is a trademark of Maxim Integrated Products, Inc. 14 ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers R1 ⎞ ⎛ VLDO _ OUT = VLDO _ SET ⎜1 + ⎟ ⎝ R2 ⎠ where VLDO_SET = 1.21V. To simplify resistor selection: ⎛ VLDO _ OUT ⎞ R1 = R2⎜ − 1⎟ ⎝ ⎠ 1.21 Since the input bias current at LDO_SET is typically less than 500nA (max), large resistance values can be used for R1 and R2 to minimize power consumption without compromising accuracy. The parallel combination of R1 and R2 should be less than 1MΩ. DirectDrive Conventional single-supply headphone amplifiers have their outputs biased about a nominal DC voltage (VDD / 2) for maximum dynamic range. Large coupling capacitors are needed to block this DC bias from the headphones. Without these capacitors, a significant amount of DC current flows to the headphone, resulting in unnecessary power dissipation and possible damage to both headphone and headphone amplifier. Maxim’s patented DirectDrive architecture uses a charge pump to create an internal negative supply voltage. It allows the MAX9789/MAX9790 headphone amplifier output to be biased about GND. With no DC component, there is no need for the large DC-blocking capacitors. Instead of two large capacitors (330µF typically required to meet Vista magnitude response specifications), the MAX9789/MAX9790 charge pump requires only two small 1µF ceramic capacitors, conserving board space, reducing cost, and improving the low-frequency response of the headphone amplifier. Previous attempts to eliminate the output coupling capacitors involved biasing the headphone return (sleeve) to the DC bias voltage of the headphone amplifiers. This method raised some issues: • The sleeve is typically grounded to the chassis. Using this biasing approach, the sleeve must be isolated from system ground, complicating product design. • During an ESD strike, the amplifier’s ESD structures are the only path to system ground. The amplifier must be able to withstand the full ESD strike. • When using the headphone jack as a line out to other equipment, the bias voltage on the sleeve may conflict with the ground potential from other equipment, resulting in large ground loop current and possible damage to the amplifiers. Low-Frequency Response In addition to the cost and size disadvantages, the DCblocking capacitors limit the low-frequency response of the amplifier and distort the audio signal: • The impedance of the headphone load and the DCblocking capacitor form a highpass filter with the -3dB point determined by: f − 3dB = TO HDA CODEC LDO_OUT R1 1μF MAX9789 LDO_SET R2 GND 1μF 1 2πRLCOUT where RL is the impedance of the headphone and COUT is the value of the DC-blocking capacitor. • The highpass filter is required by conventional singleended, single-supply headphone amplifier to block the midrail DC component of the audio signal from the headphones. Depending on the -3dB point, the filter can attenuate low-frequency signals within the audio band. Larger values of COUT reduce the attenuation, but are physically larger, more expensive capacitors. Figure 2 shows the relationship between the size of COUT and the resulting low-frequency attenuation. Note the Vista’s magnitude response specification calls for a -3dB point at 20Hz at the headphone jack. The -3dB point at 20Hz for a 32Ω headphone requires a 330µF blocking capacitor (Table 2). Figure 1. Adjustable Output Using External Feedback Resistors. ______________________________________________________________________________________ 15 MAX9789/MAX9790 The output voltage is set by the following equation: ADDITIONAL THD+N DUE TO DC-BLOCKING CAPACITORS LOW-FREQUENCY ROLLOFF (RL = 16Ω) 10 0 COUT = 100μF RL = 16Ω -3 1 DirectDrive -6 -9 330μF THD+N (%) ATTENUATION (dB) MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers -12 220μF -15 100μF -18 -21 33μF 0.1 TANTALUM 0.01 0.001 -24 ALUM/ELEC -27 0.0001 -30 1 10 100 1k 10k 10 100k 100 1k 10k 100k FREQUENCY (Hz) FREQUENCY (Hz) Figure 2. Low-Frequency Attenuation of Common DC-Blocking Capacitor Values Figure 3. Distortion Contributed by DC-Blocking Capacitors • The voltage coefficient of the capacitor, the change in capacitance due to a change in the voltage across the capacitor, distorts the audio signal. At frequencies around the -3dB point, this effect is maximized and the voltage coefficient appears as frequency-dependent distortion. Figure 3 shows the THD+N introduced by two different capacitor dielectrics. Note that around the -3dB point, THD+N increases dramatically. speed that minimizes noise generated by switching transients. Limiting the switching speed of the charge pump minimizes the di/dt noise caused by the parasitic bond wire and trace inductance. • The combination of low-frequency attenuation and frequency-dependent distortion compromises audio reproduction. DirectDrive improves low-frequency reproduction in portable audio equipment that emphasizes low-frequency effects, such as multimedia laptops, MP3, CD, and DVD players (See Table 2). Table 2. Low-Frequency Rolloff COUT (µF) f-3dB (Hz) RL = 16Ω RL = 32Ω 22 452 226 33 301 151 100 99 50 220 45 23 330* 30 15 470 21 *Vista requirement for 32Ω load. 11 Charge Pump The MAX9789/MAX9790 feature a low-noise charge pump. The 550kHz switching frequency is well beyond the audio range, and does not interfere with the audio signals. The switch drivers feature a controlled switching 16 BIAS The MAX9789/MAX9790 feature an internally generated, power-supply independent, common-mode bias voltage of 1.8V referenced to GND. BIAS provides both click-and-pop suppression and sets the DC bias level for the amplifiers. The BIAS pin should be bypassed to GND with a 1µF capacitor. No external load should be applied to BIAS. Any load lowers the BIAS voltage, affecting the overall performance of the device. Headphone and Speaker Amplifier Gain The MAX9789/MAX9790 feature programmable speaker amplifier gain, set by the logic voltages applied to pins GAIN1 and GAIN2. Table 3 shows the logic combinations that can be applied to pins GAIN1 and GAIN2 and their affects on the speaker amplifier gain. The headphone amplifier gain is fixed at 3.5dB. Table 3. MAX9789/MAX9790 Programmable Gain Settings MAX9789/MAX9790 GAIN1 GAIN2 SPEAKER MODE GAIN (dB) HEADPHONE MODE GAIN (dB) 0 0 6 3.5 0 1 10 3.5 1 0 15.6 3.5 1 1 21.6 3.5 ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers The MAX9789/MAX9790 feature control inputs for the independent enabling of the speaker and headphone amplifiers, allowing both to be active simultaneously if required. Driving SPKR_EN high disables the speaker amplifiers. Driving HP_EN low independently disables the headphone amplifiers. For applications that require only one of the amplifiers to be on at a given time, SPKR_EN and HP_EN can be tied together allowing a single logic voltage to enable either the speaker or the headphone amplifier as shown in Figure 4. MUTE The MAX9789/MAX9790 allow for the speaker and headphone amplifiers to be muted. By driving MUTE low, both the speaker and headphone amplifiers are muted. When muted, the speaker outputs remain biased at VDD / 2. Shutdown The MAX9789/MAX9790 feature a low-power shutdown mode, drawing 0.3µA of supply current. By disabling the speaker, headphone amplifiers and the LDO (for MAX9789), the MAX9789/MAX9790 enter low-power shutdown mode. Set SPKR_EN to VDD and HP_EN and LDO_EN to GND to disable the speaker amplifiers, headphone amplifiers, and LDO, respectively. Click-and-Pop Suppression Speaker Amplifier The MAX9789/MAX9790 speaker amplifiers feature Maxim’s comprehensive, industry-leading click-andpop suppression. During startup, the click-and-pop suppression circuitry eliminates any audible transient sources internal to the device. When entering shutdown, the differential speaker outputs ramp to GND quickly and simultaneously. Headphone Amplifier In conventional single-supply headphone amplifiers, the output-coupling capacitor is a major contributor of audible clicks and pops. Upon startup, the amplifier charges the coupling capacitor to its bias voltage, typically VDD / 2. Likewise, during shutdown, the capacitor is discharged to GND. A DC shift across the capacitor results, which in turn, appears as an audible transient at the headphone. Since the MAX9789/MAX9790 do not require output-coupling capacitors, no audible transient occurs. Additionally, the MAX9789/MAX9790 features extensive click-and-pop suppression that eliminates any audible transient sources internal to the device. The startup/shutdown waveform in the Typical Operating Characteristics shows that there are minimal spectral components in the audible range at the output. Applications Information BTL Speaker Amplifiers The MAX9789/MAX9790 feature speaker amplifiers designed to drive a load differentially, a configuration referred to as bridge-tied load (BTL). The BTL configuration (Figure 5) offers advantages over the singleended configuration, where one side of the load is connected to ground. Driving the load differentially doubles the output voltage compared to a singleended amplifier operating under similar conditions. The doubling of the output voltage yields four times the output power at the load. Since the differential outputs are biased at mid-supply, there is no net DC voltage across the load. This eliminates the need for DC-blocking capacitors required for single-ended amplifiers. These capacitors can be large, expensive, consume board space, and degrade low-frequency performance. +1 VOUT(P-P) MAX9789/MAX9790 SINGLE CONTROL PIN 2 x VOUT(P-P) SPKR_EN HP_EN -1 Figure 4. Enabling Either the Speaker or Headphone Amplifier with a Single Control Pin Figure 5. Bridge-Tied Load Configuration VOUT(P-P) ______________________________________________________________________________________ 17 MAX9789/MAX9790 Speaker and Headphone Amplifier Enable MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Mono Speaker Configuration Output Power (Speaker Amplifier) The MAX9789 stereo BTL Class AB speaker amplifier can be configured to drive a mono speaker. Rather than combining the CODEC’s left- and right-input signals in a resistive network prior to one channel of the speaker amplifier input, the transducer itself can be connected to the BTL speaker amplifier output as shown in Figure 6. When compared to the resistive network implementation, the configuration in Figure 6 will: 1) Eliminate noise pickup by eliminating the highimpedance node at the CODEC’s left- and rightsignal mixing point. SNR performance will be improved as a result. 2) Eliminate gain error by eliminating any resistive mismatch between the external resistance used to sum the left and right signals and the MAX9789 internal resistance. The increase in power delivered by the BTL configuration directly results in an increase in internal power dissipation over the single-ended configuration. The maximum power dissipation for a given VDD and load is given by the following equation: Power Dissipation and Heat Sinking Under normal operating conditions, the MAX9789/ MAX9790 can dissipate a significant amount of power. The maximum power dissipation for each package is given in the Absolute Maximum Ratings section under Continuous Power Dissipation, or can be calculated by the following equation: PDISSPKG(MAX) = TJ(MAX) − TA θJA where TJ(MAX) is +150°C, TA is the ambient temperature, and θJA is the reciprocal of the derating factor in °C/W as specified in the Absolute Maximum Ratings section. For example, θJA for the 32-pin TQFN-EP package is +40.2°C/W for a multilayer PC board. CODEC CIN1 SPKR_OUTL OUTL+ SPKR_INL OUTL- CIN1 SPKR_OUTR OUTR+ LINE_OUTR OUTRHP_INL HPL CIN2 LINE_OUTL HP_INR HPR Figure 6. Mono Signal Output Configuration for MAX9789 18 2VDD2 π 2RL If the power dissipation for a given application exceeds the maximum allowed for a given package, either reduce VDD, increase load impedance, decrease the ambient temperature, or add heat sinking to the device. Large output, supply, and ground PC board traces improve the maximum power dissipation in the package. Thermal-overload protection limits total power dissipation in these devices. When the junction temperature exceeds +150°C, the thermal-protection circuitry disables the amplifier output stage. The amplifiers are enabled once the junction temperature cools by +15°C. This results in a pulsing output under continuous thermal-overload conditions as the device heats and cools. Power Supplies The MAX9789/MAX9790 have separate supply pins for each portion of the device, allowing for the optimum combination of headroom and power dissipation and noise immunity. The speaker amplifiers are powered from PVDD. PVDD ranges from 4.5V to 5.5V. The headphone amplifiers are powered from HPVDD and PVSS. HPVDD is the positive supply of the headphone amplifiers and ranges from 3V to 5.5V. PVSS is the negative supply of the headphone amplifiers. Connect PVSS to CPV SS . The charge pump is powered by CPV DD . CPVDD ranges from 3V to 5.5V and should be the same potential as HPVDD. The charge pump inverts the voltage at CPVDD, and the resulting voltage appears at CPV SS . The internal LDO and the remainder of the device is powered by VDD. Component Selection MAX9789 SPKR_INR CIN2 PDISS(MAX) = Supply Bypassing The MAX9789/MAX9790 have separate supply pins for each portion of the device, allowing for the optimum combination of headroom and power dissipation and noise immunity. Speaker Amplifier Power-Supply Input (PVDD) The speaker amplifiers are powered from PVDD. PVDD ranges from 4.5V to 5.5V. Bypass PVDD with a 0.1µF capacitor to PGND. Note additional bulk capacitance is required at the device if long input traces between PVDD and the power source are used. ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Power Supply and LDO Input (VDD) The internal LDO and the remainder of the device is powered by V DD . V DD ranges from 4.5V to 5.5V. Bypass VDD with a 0.1µF capacitor to GND and two 1µF capacitors in parallel to GND. Note additional bulk capacitance is required at the device if long input traces between VDD and the power source are used. Input Filtering The input capacitor (CIN), in conjunction with the amplifier input resistance (RIN), forms a highpass filter that removes the DC bias from the incoming signal. The ACcoupling capacitor allows the amplifier to bias the signal to an optimum DC level. Assuming zero source impedance, the -3dB point of the highpass filter is given by: f − 3dB = 1 2πRINCIN RIN is the amplifier’s internal input resistance value given in the Electrical Characteristics. Choose CIN such that f-3dB is well below the lowest frequency of interest. Setting f-3dB too high affects the amplifier’s low frequency response. Use capacitors with adequately low voltage coefficient dielectrics, such as 1206-sized X7R ceramic capacitors. Capacitors with higher voltage coefficients result in increased distortion at low frequencies (see Figure 7). INPUT COUPLING CAPACITOR-INDUCED THD+N vs. FREQUENCY (HEADPHONE MODE) -50 -55 0402 6.3V X5R 10% 1μF -60 THD+N (dB FS) The headphone amplifiers are powered from HPVDD and PVSS. HPVDD is the positive supply of the headphone amplifiers and ranges from 3.0V to 5.5V. Bypass HPVDD with a 10µF capacitor to PGND. PVSS is the negative supply of the headphone amplifiers. Bypass PVSS with a 1µF capacitor to PGND. Connect PVSS to CPV SS . The charge pump is powered by CPV DD . CPVDD ranges from 3.0V to 5.5V and should be the same potential as HPVDD. Bypass CPVDD with a 1µF capacitor to PGND. The charge pump inverts the voltage at CPVDD, and the resulting voltage appears at CPVSS. A 1µF capacitor must be connected between C1N and C1P. MAX9789/MAX9790 Headphone Amplifier Power-Supply Input (HPVDD and PVSS) 0603 10V X5R 10% 1μF -65 -70 -75 -80 0805 25V X7R 10% 1μF 1206 25 X7R 10% 1μF -85 -90 10 100 VOUT = -3dB FS FS = 1VRMS RL = 32Ω 1000 FREQUENCY (Hz) Figure 7. Input Coupling Capacitor-Induced THD+N vs. Frequency (Headphone Mode) BIAS Capacitor BIAS is the output of the internally generated DC bias voltage. The BIAS bypass capacitor, CBIAS improves PSRR and THD+N by reducing power supply and other noise sources at the common-mode bias node, and also generates the clickless/popless, startup/shutdown DC bias waveforms for the speaker and headphone amplifiers. Bypass BIAS with a 1µF capacitor to GND. Charge-Pump Capacitor Selection Use capacitors with an ESR less than 100mΩ for optimum performance. Low ESR ceramic capacitors minimize the output resistance of the charge pump. For best performance over the extended temperature range, select capacitors with an X7R dielectric. Flying Capacitor (C1) The value of the flying capacitor (C1) affects the load regulation and output resistance of the charge pump. A C1 value that is too small degrades the device’s ability to provide sufficient current drive, which leads to a loss of output voltage. Connect a 1µF capacitor between C1P and C1N. ______________________________________________________________________________________ 19 MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Output Capacitor (C2) The output capacitor value and ESR directly affect the ripple at CPVSS. Increasing the value of C2 reduces output ripple. Likewise, decreasing the ESR of C2 reduces both ripple and output resistance. Lower capacitance values can be used in systems with low maximum output power levels. CPVDD Bypass Capacitor (C3) The CPVDD bypass capacitor (C3) lowers the output impedance of the power supply and reduces the impact of the MAX9789/MAX9790’s charge-pump switching transients. Bypass CPVDD with 1µF, the same value as C1, and place it physically close to the CPVDD and CPGND pins. Layout and Grounding Proper layout and grounding are essential for optimum performance. Use large traces for the power-supply inputs and amplifier outputs to minimize losses due to parasitic trace resistance, as well as route heat away from the device. Good grounding improves audio performance, minimizes crosstalk between channels, and prevents switching noise from coupling into the audio signal. Connect PGND and GND together at a single point on the PC board. Route PGND and all traces that carry switching transients away from GND and the traces and components in the audio signal path. 20 Connect C2 and C3 to the PGND plane. Connect PVSS and CPVSS together at C2. Place the charge-pump capacitors (C1, C2, and C3) as close as possible to the device. Bypass PVDD with a 0.1µF capacitor to PGND. Place the bypass capacitors as close as possible to the device. Use large, low-resistance output traces. As load impedance decreases, the current drawn from the device outputs increase. At higher current, the resistance of the output traces decrease the power delivered to the load. For example, if 2W is delivered from the speaker output to a 4Ω load through a 100mΩ trace, 49mW is consumed in the trace. If power is delivered through a 10mΩ trace, only 5mW is consumed in the trace. Large output, supply and GND traces also improve the power dissipation of the device. The MAX9789/MAX9790 thin QFN package features an exposed thermal pad on its underside. This pad lowers the package’s thermal resistance by providing a direct heat conduction path from the die to the printed circuit board. Connect the exposed thermal pad to GND by using a large pad and multiple vias to the GND plane. ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers 4.5V TO 5.5V 1.0µF 4.5V TO 5.5V 1.0µF 0.1µF 0.1µF VDD PVDD 8, 18 30 MAX9789 1.0µF 1.0µF SPKR_INL SPKR_INR 3 STEREO BTL AMPLIFIER 2 6 OUTL+ 7 OUTL- 20 OUTR+ 19 OUTR- 24 BIAS TO HPVDD 1.0µF 1.0µF 3V TO 5.5V HP_INL 27 HP_INR 26 HP_EN 22 MUTE 25 SPKR_EN 23 1.0µF GAIN1 15 HPR 17 HPVDD 9 CPVDD LDO_EN 31 LDO_OUT 1.0µF 1 LDO BLOCK C1P 11 CPGND 12 C1N C3 10µF C1 1µF 29 28 GND LOGIC PINS CONFIGURED FOR: LDO_EN = 1, LDO ENABLED SPKR_EN = 0, SPEAKER AMPLIFIERS ENABLED HP_EN = 1, HEADPHONE AMPLIFIER ENABLED MUTE = 1, MUTE DISABLED GAIN1 = 0 GAIN = 0, 6dB SPEAKER GAIN 10 4 CHARGE PUMP LDO_SET 3V TO 5.5V CONTROL 3V TO 5.5V 1.0µF HPL TO PVSS GAIN2 32 TO CODEC 16 5, 21 PGND 14 13 PVSS CPVSS C2 1.0µF ______________________________________________________________________________________ 21 MAX9789/MAX9790 Block Diagrams Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789/MAX9790 Block Diagrams (continued) 4.5V TO 5.5V 0.1μF 0.1μF VDD 30 PVDD 8, 18 MAX9790 1.0μF 1.0μF SPKR_INL SPKR_INR 3 STEREO BTL AMPLIFIER 2 6 OUTL+ 7 OUTL- 20 OUTR+ 19 OUTR- 24 BIAS TO HPVDD 1.0μF 1.0μF HP_INL 27 HP_INR 26 1.0μF 16 HPL 15 HPR TO PVSS 3V TO 5.5V HP_EN 22 MUTE 25 17 HPVDD 23 9 CPVDD SPKR_EN CONTROL GAIN2 32 GAIN1 C1P 11 CPGND 12 C1N 31 CHARGE PUMP 4, 28 GND LOGIC PINS CONFIGURED FOR: SPKR_EN = 0, SPEAKER AMPLIFIERS ENABLED HP_EN = 1, HEADPHONE AMPLIFIER ENABLED MUTE = 1, MUTE DISABLED GAIN1 = 0 GAIN = 0, 6dB SPEAKER GAIN 22 10 5, 21 PGND 14 13 PVSS CPVSS 3V TO 5.5V C3 10μF C1 1μF C2 1.0μF ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers 5.0V 0.1μF 1μF CBULK 1μF BIAS VDD VLDO_OUT 5.0V 10μF PVDD HPVDD 1μF CIN 1μF SPKR_L SPKR_INR CIN 1μF OUTR+ 4Ω HP_INR CIN 1μF HP_L OUTR- HP_INL HPL 5.0V MONO DGND 4Ω OUTL- SPKR_INL CIN 1μF SPKR_R HDA CODEC HP_R OUTL+ MAX9789 AGND HPR CPVDD C3 1μF C1 1μF C1P 4.75V LDO_SET C1N LDO_OUT SPKR_EN μC 1μF 1μF HP_EN LDO_EN CPVSS GAIN1 C2 1μF PVSS GAIN2 CPGND MUTE GND PGND 12V 100μF 1μF VDD FS2 FS1 OUT+ G1 OUT- 8Ω G2 SHDN MAX9713 C1P 0.47μF 0.1μF IN+ C1N 0.47μF VDD IN- 1μF SS CHOLD REG 0.47μF 0.01μF PGND AGND ______________________________________________________________________________________ 23 MAX9789/MAX9790 System Diagrams Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789/MAX9790 System Diagrams (continued) 1μF 1μF +5V +3.3V PVDD HPVDD 10μF 0.1μF VDD VLDO_OUT OUTL+ 1μF SPKR_L OUTL- SPKR_INL 1μF SPKR_R HDA CODEC HP1_R SPKR_INR OUTR+ 1μF HP_INR OUTR- 1μF HP_INL HP1_L HP1 HPL +3.3V MAX9789 HP2_R HPR CPVDD HP2_L C3 1μF DGND AGND C1 1μF C1P 4.75V LDO_SET C1N SPKR_EN LDO_OUT 1μF HP_EN μC 1μF LDO_EN CPVSS GAIN2 MUTE C2 1μF PVSS GAIN1 CPGND PGND GND C1P SHDNR 1μF SHDNL C1N 1μF MAX4411 HP2 OUTL INR 1μF OUTR INL +3.3V PVDD 1μF PVSS SVSS SVDD SGND 24 PGND 1μF ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers BIAS SPKR_EN HP_EN PGND OUTR+ OUTR- PVDD HPVDD BIAS SPKR_EN HP_EN PGND OUTR+ OUTR- PVDD HPVDD TOP VIEW 24 23 22 21 20 19 18 17 24 23 22 21 20 19 18 17 MUTE 25 16 HPL MUTE 25 16 HPL HP_INR 26 15 HPR HP_INR 26 15 HPR HP_INL 27 14 PVSS HP_INL 27 14 PVSS 13 13 CPVSS 12 C1N 11 CPGND 10 9 6 7 8 PVDD SPKR_INL 5 OUTL- SPKR_INR 4 OUTL+ 3 PGND 2 LDO_EN 1 LDO_SET GAIN2 32 C1P GAIN1 31 CPVDD GAIN2 32 EP* + 1 2 3 4 5 6 7 8 PVDD VDD 30 OUTL- CPGND OUTL+ 11 MAX9790 PGND EP* + C1N N.C. 29 GND GAIN1 31 GND 28 SPKR_INL VDD 30 CPVSS 12 SPKR_INR MAX9789 LDO_OUT 29 N.C. GND 28 C1P 9 CPVDD TQFN TQFN *EP = EXPOSED PADDLE *EP = EXPOSED PADDLE Simplified Block Diagrams (continued) SPEAKER SUPPLY 4.5V TO 5.5V 10 Chip Information PROCESS: BiCMOS HEADPHONE SUPPLY 3.0V TO 5.5V MAX9790 SPKR_INR SPKR_INL HP_INR HP_INL SPKR_EN HP_EN MUTE GAIN1 GAIN2 ______________________________________________________________________________________ 25 MAX9789/MAX9790 Pin Configurations Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 32 TQFN-EP T3255N-1 21-0140 QFN THIN.EPS MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers 26 ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers ______________________________________________________________________________________ 27 MAX9789/MAX9790 Package Information (continued) For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. MAX9789/MAX9790 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Revision History REVISION NUMBER REVISION DATE 2 8/08 Added MAX9789C to data sheet and made miscellaneous clarifications 3 9/09 Corrected the Block Diagrams DESCRIPTION PAGES CHANGED 1–11, 13, 14, 18 21 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 28 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.