19-0606; Rev 0; 9/06 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Features The MAX9789A/MAX9790A combine a stereo, 2W Class AB speaker power amplifier with a stereo 100mW DirectDrive™ headphone amplifier in a single device. The MAX9789A/MAX9790A 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 (MAX9789A) 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 ±8kV ESD-Protected Headphone Driver Outputs o Available in 32-Pin Thin QFN (5mm x 5mm x 0.8mm) Package The MAX9789A 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. By disabling the speaker and headphone amplifiers, and the LDO (for MAX9789A), the MAX9789A/MAX9790A enter low-power shutdown mode and draw only 0.3µA. The MAX9789A/MAX9790A 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. Ordering Information PIN-PACKAGE INTERNAL LDO PKG CODE MAX9789AETJ+ 32 Thin QFN-EP* Yes T3255N-1 MAX9790AETJ+ 32 Thin QFN-EP* No T3255N-1 PART Note: All devices are specified over the -40°C to +85°C extended temperature range. +Denotes lead-free package. *EP = Exposed paddle. Simplified Block Diagrams SPEAKER SUPPLY 4.5V TO 5.5V HEADPHONE SUPPLY 3.0V TO 5.5V SPKR_INR MAX9789A SPKR_INL Applications HP_INR Notebook Computers Tablet PCs HP_INL Portable Multimedia Players SPKR_EN HP_EN MUTE GAIN1 GAIN2 Pin Configurations appear at end of data sheet. 4.5V TO 5.5V LDO 1.21V TO 4.75V †U.S. Patent # 7,061,327 Windows Vista is a trademark of Microsoft Corp. Simplified Block Diagrams continued at end of data sheet. ________________________________________________________________ Maxim Integrated Products 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. 1 MAX9789A/MAX9790A General Description MAX9789A/MAX9790A 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 32-Pin Thin QFN Multilayer Board (derate 24.9 mW/°C above +70°C) .............................1990mW 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 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 = LDO_EN (MAX9789A only) = +5V, GND = PGND = CPGND = LDO_SET (MAX9789A only) = 0V, ILDO_OUT (MAX9789A only) = 0, C1 = C2 = CBIAS = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS GENERAL Supply Voltage Headphone Supply Voltage Quiescent Current VDD, PVDD CPVDD, HPVDD IDD Guaranteed by PSRR and LDO Line Regulation Tests 4.5 5.5 V Guaranteed by PSRR Test 3.0 5.5 V SPKR_EN HP_EN 1 (MAX9789A) 0 (MAX9789A) 0.1 0.16 mA 1 (MAX9790A) 0 (MAX9790A) 0.3 6 µA 1 1 7 13 0 0 14 29 0 1 SPKR_EN = VDD, HP_EN = LDO_EN = GND 18 40 0.3 6 1.8 1.9 mA Shutdown Current ISHDN Bias Voltage VBIAS Shutdown to Full Operation tSON 100 ms Gain Switching Time tSW 10 µs ±0.1 dB 1.7 Channel-to-Channel Gain Tracking µA V SPEAKER AMPLIFIER Output Power Total Harmonic Distortion Plus Noise POUT THD+N THD+N = 1%, f = 1kHz, TA = +25°C 2 PSRR 2 RL = 8Ω 1 RL = 8Ω, POUT = 1W, f = 1kHz 0.002 RL = 4Ω, POUT = 1W, f = 1kHz 0.004 VDD = 4.5V to 5.5V, TA = +25°C Power-Supply Rejection Ratio RL = 4Ω 72 W % 90 f = 1kHz, 200mVP-P (Note 3) 70 f = 10kHz, 200mVP-P (Note 3) 50 _______________________________________________________________________________________ dB Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers (VDD = PVDD = CPVDD = HPVDD = LDO_EN (MAX9789A only) = +5V, GND = PGND = CPGND = LDO_SET (MAX9789A only) = 0V, ILDO_OUT (MAX9789A only) = 0, C1 = C2 = CBIAS = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Voltage Gain SYMBOL AV CONDITIONS MIN TYP GAIN1 GAIN2 0 0 6 0 1 10 1 0 15.6 1 1 21.6 MAX UNITS dB Measured at speaker amplifier inputs Input Impedance RIN GAIN1 GAIN2 0 0 80 0 1 65 1 0 45 1 1 25 Output Offset Voltage VOS Measured between OUT_+ and OUT_-, TA = +25°C Click-and-Pop Level KCP RL = 8Ω, peak voltage, Into shutdown A-weighted, 32 samples per second (Notes 2, 3) Out of shutdown Signal-to-Noise Ratio ±1 kΩ ±15 mV -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 MAX9789A/MAX9790A ELECTRICAL CHARACTERISTICS (continued) MAX9789A/MAX9790A Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers ELECTRICAL CHARACTERISTICS (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN (MAX9789A only) = +5V, GND = PGND = CPGND = LDO_SET (MAX9789A only) = 0V, ILDO_OUT (MAX9789A only) = 0, C1 = C2 = CBIAS = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Power-Supply Rejection Ratio (Note 5) Voltage Gain SYMBOL CONDITIONS HPVDD = 3V to 5.5V, TA = +25°C PSRR MIN TYP 70 95 f = 1kHz, VRIPPLE = 200mVP-P (Note 3) 84 f = 10kHz, VRIPPLE = 200mVP-P (Note 3) 63 AV MAX dB 3.5 dB Input Impedance RIN Measured at headphone amplifier inputs 40 80 kΩ Output Offset Voltage VOS TA = +25°C ±2 ±7 mV KCP RL = 32Ω, peak voltage, Into shutdown A-weighted, 32 samples per second (Notes 2, 3) Out of shutdown RL = 32Ω, f = 1kHz, A-weighted, FS = 0.300VRMS, VOUT = 300µVRMS -60 Click-and-Pop Level Dynamic Range Signal-to-Noise Ratio DR SNR 20 UNITS dBV -60 89 dB FS RL = 10kΩ, f = 1kHz, A-weighted, FS = 0.707VRMS, VOUT = 707µVRMS RL = 32Ω, POUT = 60mW 97 22Hz to 22kHz 100 A-weighted 103 dB Noise Vn BW = 22Hz to 22kHz 12 µVRMS Capacitive-Load Drive CL No sustained oscillations 200 pF L to R, R to L, 20kHz AES17 BW = 20Hz to 20kHz Crosstalk Slew Rate RL = 32Ω, FS = 0.300VRMS, VOUT = 30mVRMS -74 RL = 10kΩ, FS = 0.707VRMS, VOUT = 70.7mVRMS -77 dB SR ESD ESD Charge-Pump Frequency fOSC 0.4 Human Body Model (HPR, HPL) V/µs ±8 500 550 kV 600 kHz 5.5 V LOW-DROPOUT LINEAR REGULATOR Regulator Input Voltage Range VDD Ground Current IGND Output Current IOUT Inferred from line regulation 4.5 IOUT = 0mA 0.1 IOUT = 120mA -40 120 Crosstalk VOUT = 4.75V, f = 1kHz, speaker POUT = 2W Fixed Output Voltage Accuracy IOUT = 1mA Adjustable Output Voltage Range LDO_SET Reference Voltage -88 1.21 VSET 1.19 LDO_SET Dual-Mode Threshold 1.21 ISET Dropout Voltage (Note 5) VDO VOUT = 4.75V (fixed output operation), TA = +25°C mA mA dB ±1.5 % 4.75 V 1.23 200 LDO_SET Input Bias Current (Note 4) 4 0.16 V mV ±20 ±500 IOUT = 50mA 25 50 IOUT = 120mA 75 150 nA mV _______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers (VDD = PVDD = CPVDD = HPVDD = LDO_EN (MAX9789A only) = +5V, GND = PGND = CPGND = LDO_SET (MAX9789A only) = 0V, ILDO_OUT (MAX9789A only) = 0, C1 = C2 = CBIAS = 1µF. RL = ∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL Current Limit CONDITIONS MIN TYP ILIM Startup Time UNITS mA 20 µs 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 f = 1kHz 59 f = 10kHz 42 Output Voltage Noise 20Hz to 22kHz, CLDO_OUT = 2 x 1µF, ILDO_OUT = 120mA 125 -4.8 MAX 300 +0.8 +4.8 mV/V 0.2 mV/mA dB µVRMS DIGITAL INPUTS (SPKR_EN, HP_EN, MUTE, GAIN1, GAIN2, LDO_EN (MAX9789A Only)) Input-Voltage High VINH Input-Voltage Low VINL 2 V Input Bias Current 0.8 V ±1 µA Note 1: All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design. Note 2: 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 3: Amplifier inputs AC-coupled to GND. Note 4: Maximum value is due to test limitations. Note 5: VLDO_OUT = VLDO_OUTNOMINAL - 2%. Typical Operating Characteristics (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_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 -80 RL = 10kΩ 1 fIN = 20Hz 0.1 fIN = 10kHz 0.01 -90 -100 10 MAX9789A toc03 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 MAX9789A toc01 -60 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT VOLTAGE (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) MAX9789A toc02 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) fIN = 1kHz -110 0.001 -100 10 100 1k FREQUENCY (Hz) 10k 100k 10 100 1k FREQUENCY (Hz) 10k 100k 0 0.5 1.0 1.5 2.0 OUTPUT VOLTAGE (VRMS) _______________________________________________________________________________________ 5 MAX9789A/MAX9790A ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_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.) -20 CROSSTALK (dB) 0.1 fIN = 10kHz -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 10k FS = 0.300VRMS VOUT = -60dB FS RL = 10kΩ 5k 0 100k 10k 15k 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 MAX9789A toc09 -75 MAX9789A toc07 -75 MAX9789A toc08 THD+N (%) 1 fIN = 20Hz FS = 0.707VRMS VOUT = -20dB FS RL = 10kΩ -10 CROSSTALK (dB) HPVDD = 3V RL = 10kΩ HEADPHONE OUTPUT SPECTRUM 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 MAX9789A toc06 0 MAX9789A toc04 10 CROSSTALK vs. FREQUENCY (HEADPHONE MODE) MAX9789A toc05 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT VOLTAGE (HEADPHONE MODE) VOUT = -3dB FS -80 -85 -90 THD+N (dB FS) THD+N (dB FS) THD+N (dB FS) -85 -85 -90 -90 -95 -100 -95 -95 FS = 0.707VRMS RL = 3Ω -100 100 1k 10k 100k -105 FS = 0.707VRMS RL = 4Ω -100 10 10 FS = 0.707VRMS RL = 8Ω -110 100 1k 10k 100k 100 10 1k 10k 100k FREQUENCY (Hz) FREQUENCY (Hz) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (SPEAKER MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (SPEAKER MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (SPEAKER MODE) RL = 4Ω fIN = 10kHz 0.1 THD+N (%) 0.1 RL = 8Ω 1 1 THD+N (%) 1 10 MAX9789A toc11 10 MAX9789A toc10 RL = 3Ω MAX9789A toc12 FREQUENCY (Hz) 10 THD+N (%) MAX9789A/MAX9790A Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers fIN = 10kHz 0.1 fIN = 10kHz fIN = 20Hz fIN = 1kHz 0.01 fIN = 1kHz fIN = 20Hz 0.001 fIN = 20Hz 0.001 0 0.5 1.0 1.5 2.0 OUTPUT POWER (W) 6 0.01 0.01 2.5 3.0 0 0.5 fIN = 1kHz 1.0 1.5 OUTPUT POWER (W) 2.0 2.5 0.001 0 0.5 1.0 OUTPUT POWER (W) _______________________________________________________________________________________ 1.5 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers -50 LEFT TO RIGHT RIGHT TO LEFT -70 -80 -90 -100 100 1k 10k 100k 2.5 THD+N = 10% 2.0 1.5 1.0 THD+N = 1% 0 0 5k FREQUENCY (Hz) 10k 15k FREQUENCY (Hz) 20k POWER DISSIPATION PER CHANNEL vs. OUTPUT POWER (SPEAKER MODE) 1.50 fIN = 1kHz 1.25 1 10 RL (Ω) 100 POWER-SUPPLY REJECTION RATIO (SPEAKER MODE) 0 MAX9789A toc16 10 fIN = 1kHz 3.0 0.5 VRIPPLE = 200mVP-P OUTPUT REFERRED -10 -20 -30 1.00 PSRR (dB) -60 3.5 MAX9789A toc17 -40 FS = 0.707VRMS VOUT = -60dB FS RL = 8Ω OUTPUT POWER (W) CROSSTALK (dB) -30 POWER DISSIPATION PER CHANNEL (W) CROSSTALK (dB) -20 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 MAX9789A toc14 FS = 0.707VRMS VOUT = -20dB FS RL = 8Ω MAX9789A toc13 0 -10 OUTPUT POWER vs. LOAD RESISTANCE (SPEAKER MODE) SPEAKER OUTPUT SPECTRUM MAX9789A toc15 CROSSTALK vs. FREQUENCY (SPEAKER MODE) 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 SPEAKER STARTUP WAVEFORM 10 100 1k 10k FREQUENCY (Hz) SPEAKER SHUTDOWN WAVEFORM MAX9789A toc18 20ms/div 100k MAX9789A toc19 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 _______________________________________________________________________________________ 7 MAX9789A/MAX9790A Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_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, GND = PGND = CPGND = LDO_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.) -75 VOUT = -3dB FS -85 -90 VOUT = -3dB FS -80 -70 -75 THD+N (dB FS) -80 -70 THD+N (dB FS) -85 -90 -85 -90 -95 -95 -95 -100 -100 FS = 0.300VRMS RL = 32Ω -105 -110 10 100 HPVDD = 3V FS = 0.300VRMS RL = 32Ω -105 -110 1k 10k 100k 10 VOUT = -3dB FS -80 -100 FS = 0.300VRMS RL = 16Ω -105 -110 100 1k 10k 10 100k 100 1k 10k 100k FREQUENCY (Hz) FREQUENCY (Hz) FREQUENCY (Hz) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE) MAX9789A toc25 -75 10 VOUT = -3dB FS -80 f = 10kHz -85 -90 -95 f = 20Hz 0.1 -100 HPVDD = 3V FS = 0.300VRMS RL = 16Ω -105 -110 10 100 10k 100k RL = 16Ω 0 f = 1kHz 0.1 f = 1kHz 0.01 1k f = 10kHz 1 THD+N (%) THD+N (%) 1 50 100 150 f = 20Hz RL = 32Ω 0.01 0 200 20 40 60 80 100 FREQUENCY (Hz) OUTPUT POWER (mW) OUTPUT POWER (mW) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE) CROSSTALK vs. FREQUENCY (HEADPHONE MODE) 10 MAX9789A toc26 10 0 -20 f = 10kHz f = 1kHz 0.1 CROSSTALK (dB) f = 20Hz -30 f = 10kHz 1 THD+N (%) 1 f = 20Hz 0.1 FS = 0.300VRMS VOUT = -20dB FS RL = 32Ω -10 MAX9789A toc28 -70 MAX9789A toc24 10 MAX9789A toc23 -65 MAX9789A toc27 THD+N (dB FS) -75 -65 MAX9789A toc21 -70 THD+N (dB FS) -65 MAX9789A toc20 -65 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) MAX9789A toc22 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE) THD+N (%) MAX9789A/MAX9790A Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers f = 1kHz -40 -50 -60 LEFT TO RIGHT -70 -80 -90 HPVDD = 3V RL = 16Ω 0.01 0 50 100 OUTPUT POWER (mW) 8 HPVDD = 3V RL = 32Ω 0.01 150 0 20 40 60 OUTPUT POWER (mW) 80 100 -100 RIGHT TO LEFT -110 10 100 1k FREQUENCY (Hz) _______________________________________________________________________________________ 10k 100k Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers 100 THD+N = 10% 50 MAX9789A toc31 MAX9789A toc30 HPVDD = 3V fIN = 1kHz THD+N = 10% 50 THD+N = 1% 0 0 POWER DISSIPATION PER CHANNEL vs. OUTPUT POWER (HEADPHONE MODE) 15 MAX9789A toc32 300 275 250 225 200 175 150 125 100 75 10 20 RL = 16Ω RL = 32Ω 50 25 0 1000 125 HPVDD = 3V 100 75 RL = 16Ω 50 RL = 32Ω 25 10 125 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (HEADPHONE MODE) 100 RL = 16Ω 75 50 RL = 32Ω 25 THD+N = 1% fIN = 1kHz 0 0 20 40 60 OUTPUT POWER PER CHANNEL (mW) 80 3.0 3.5 4.0 HPVDD (V) -10 -20 MAX9789A toc35 VRIPPLE = 200mVP-P OUTPUT REFERRED 4.5 5.0 HEADPHONE SHUTDOWN WAVEFORM HEADPHONE STARTUP WAVEFORM MAX9789A toc37 MAX9789A toc36 0 1000 125 0 25 50 75 100 OUTPUT POWER PER CHANNEL (mW) 100 RL (Ω) HEADPHONE OUTPUT POWER vs. HPVDD MAX9789A toc33 10 MAX9789A toc34 POWER DISSIPATION vs. OUTPUT POWER (HEADPHONE MODE) 5 HEADPHONE OUTPUT POWER (mW) FREQUENCY (kHz) 100 RL (Ω) 0 HP_EN HP_EN 5V/div -30 PSRR (dB) 100 OUTPUT POWER (mW) OUTPUT POWER (mW) fIN = 1kHz THD+N = 1% 0 POWER DISSIPATION PER CHANNEL (mW) 150 MAX9789A toc29 FS = 0.707VRMS VOUT = -60dB FS RL = 32Ω POWER DISSIPATION PER CHANNEL (mW) AMPLITUDE (dB) 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 OUTPUT POWER vs. LOAD RESISTANCE (HEADPHONE MODE) OUTPUT POWER vs. LOAD RESISTANCE (HEADPHONE MODE) HEADPHONE OUTPUT SPECTRUM MAX9789A/MAX9790A Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_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.) 5V/div -40 -50 -60 HP_ 500mV/div -70 HP_ 500mV/div -80 -90 -100 10 100 1k 10k FREQUENCY (Hz) 100k 20ms/div 20ms/div _______________________________________________________________________________________ 9 Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_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.) SUPPLY CURRENT vs. SUPPLY VOLTAGE SPKR_EN = 0 HP_EN = 1 10 5 SPKR_EN = 1 HP_EN = 1 SPKR_EN = 0 HP_EN = 0 SPKR_EN = 1 HP_EN = 0 0 -5 SPKR_EN = 5V HP_EN = 0 LDO_EN = 0 (MAX9789A) 0.2 0.1 0 4.75 5.00 5.25 SUPPLY VOLTAGE (V) 5.50 4.50 LDO OUTPUT VOLTAGE ACCURACY vs. ILOAD 1.0 0.5 0 -0.5 -1.0 -1.5 0.10 LDO OUTPUT VOLTAGE ACCURACY (%) -2.0 VLDO_OUT = 4.75V ILDO_OUT = 0A 0.05 0 -0.05 -0.10 0 25 50 75 100 ILOAD (mA) 125 150 0 LDO OUTPUT VOLTAGE ACCURACY vs. TEMPERATURE 1.0 0.5 0 -0.5 -1.0 100 90 DROPOUT VOLTAGE (mV) ILDO_OUT = 1mA 1.5 3.0 DROPOUT VOLTAGE vs. ILOAD MAX9789A toc42 2.0 0.5 1.0 1.5 2.0 2.5 AMPLIFIER OUTPUT POWER (W) MAX9789A toc43 LDO OUTPUT VOLTAGE ACCURACY (%) VLDO_OUT = 4.75V 1.5 5.50 LDO OUTPUT VOLTAGE ACCURACY vs. AMPLIFIER OUTPUT POWER MAX9789A toc40 2.0 4.75 5.00 5.25 SUPPLY VOLTAGE (V) MAX9789A toc41 4.50 VLDO_OUT = 4.75V 80 70 60 50 VLDO_OUT = 3.3V 40 30 20 -1.5 10 0 -2.0 -40 10 MAX9789A toc39 0.3 SHUTDOWN CURRENT (μA) 15 SUPPLY CURRENT (mA) SHUTDOWN CURRENT vs. SUPPLY VOLTAGE MAX9789A toc38 20 LDO OUTPUT VOLTAGE ACCURACY (%) MAX9789A/MAX9790A Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers -15 10 35 TEMPERATURE (°C) 60 85 0 25 50 75 100 125 ILOAD (mA) ______________________________________________________________________________________ 150 Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers RIPPLE REJECTION vs. FREQUENCY -30 -40 VLDO_OUT = 4.75V -50 -60 -70 MAX9789A toc45 1 0.1 VLDO_OUT = 3.3V -80 -90 0.01 10 100 1k 10k 100k 10 100 FREQUENCY (Hz) 1k 10k 100k FREQUENCY (Hz) LINE-TRANSIENT RESPONSE LDO LOAD-TRANSIENT RESPONSE MAX9789A toc46 MAX9789A toc47 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 ILOAD = 0mA -30 LDO_EN 2V/div -40 VLDO_OUT 2V/div -50 MAX9789A toc49 LDO CROSSTALK vs. FREQUENCY MAX9789A toc48 CROSSTALK (dB) RIPPLE REJECTION (dB) -20 OUTPUT NOISE (μV√Hz) VRIPPLE = 200mVP-P IOUT = 10mA OUTPUT REFERRED -10 OUTPUT NOISE vs. FREQUENCY 10 MAX9789A toc44 0 -60 -70 RIGHT SPEAKER TO LDO -80 -90 -100 -110 LEFT SPEAKER TO LDO -120 200ms/div 10 100 1k 10k FREQUENCY (Hz) 100k ______________________________________________________________________________________ 11 MAX9789A/MAX9790A Typical Operating Characteristics (continued) (VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_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.) MAX9789A/MAX9790A Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Pin Description PIN NAME FUNCTION MAX9789A MAX9790A 12 Regulator Feedback Input. Connect to GND for 4.75V fixed output. Connect to a resistordivider for adjustable output. See Figure 1. 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 Headphone Amplifier Negative Power Supply. Connect a 1µF capacitor between PVSS and PGND. 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 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 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. Active-High Headphone Amplifier Enable 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 (MAX9789A). Bypass with one 0.1µF capacitor and two 1µF capacitors to GND (MAX9789A). Bypass with one 0.1µF capacitor and one 1µF capacitor to GND (MAX9790A). No Connection. Not internally connected. Exposed Paddle. Connect to GND. ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers The MAX9789A/MAX9790A 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 MAX9789A/MAX9790A feature high +90dB PSRR, low 0.002% THD+N, industry-leading clickand-pop performance, low-power shutdown mode, and excellent RF immunity. The MAX9789A incorporates an integrated LDO that serves as a clean power supply for a CODEC or other circuits. The MAX9789A/MAX9790A is Microsoft Windows Vista compliant. See Table 1 for a comparison of the Microsoft Windows Vista premium mobile specifications and MAX9789A/MAX9790A 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 MAX9789A/MAX9790A 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, while the headphone amplifier outputs (IEC Air Discharge) can withstand ±8kV ESD strikes. An additional feature of the speaker amplifiers is that there is no phase inversion from input to output. Low-Dropout Linear Regulator (MAX9789A Only) The MAX9789A’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. MAX9789A/MAX9790A Specifications DEVICE TYPE WINDOWS PREMIUM MOBILE Vista SPECIFICATIONS MAX9789A/MAX9790A 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, DR, FREQUENCY ACCURACY, and CROSSTALK should be measured in accordance with AES-17 audio measurements standards. Dual Mode is a trademark of Maxim Integrated Products, Inc. ______________________________________________________________________________________ 13 MAX9789A/MAX9790A Detailed Description MAX9789A/MAX9790A Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers The output voltage is set by the following equation: 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 MAX9789A/MAX9790A 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 MAX9789A/MAX9790A 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 = LDO_OUT R1 1μF MAX9789A 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. 14 ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers 10 0 COUT = 100μF RL = 16Ω -3 -9 330μF THD+N (%) ATTENUATION (dB) 1 DirectDrive -6 -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 100k 10k 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 MAX9789A/MAX9790A 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 BIAS The MAX9789A/MAX9790A 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 MAX9789A/MAX9790A 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. MAX9789A/MAX9790A Programmable Gain Settings MAX9789A/MAX9790A SPEAKER MODE GAIN (dB) HEADPHONE MODE GAIN (dB) 0 6 3.5 1 10 3.5 1 0 15.6 3.5 1 1 21.6 3.5 GAIN1 GAIN2 0 0 ______________________________________________________________________________________ 15 MAX9789A/MAX9790A ADDITIONAL THD+N DUE TO DC-BLOCKING CAPACITORS LOW-FREQUENCY ROLLOFF (RL = 16Ω) MAX9789A/MAX9790A Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Speaker and Headphone Amplifier Enable The MAX9789A/MAX9790A 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 MAX9789A/MAX9790A 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. 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 MAX9789A/MAX9790A do not require output-coupling capacitors, no audible transient occurs. Additionally, the MAX9789A/MAX9790A 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 Shutdown The MAX9789A/MAX9790A feature a low-power shutdown mode, drawing 0.3µA of supply current. By disabling the speaker, headphone amplifiers and the LDO (for MAX9789A), the MAX9789A/MAX9790A enter lowpower shutdown mode. Set SPKR_EN to V DD 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 MAX9789A/MAX9790A 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. BTL Speaker Amplifiers The MAX9789A/MAX9790A 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) MAX9789A/MAX9790A SINGLE CONTROL PIN HP_EN Figure 4. Enabling Either the Speaker or Headphone Amplifier with a Single Control Pin 16 2 x VOUT(P-P) SPKR_EN -1 Figure 5. Bridge-Tied Load Configuration ______________________________________________________________________________________ VOUT(P-P) Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Output Power (Speaker Amplifier) 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 MAX9789A/ MAX9790A 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+ OUTR- CIN2 HP_INL HPL CIN2 LINE_OUTL HP_INR 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 MAX9789A/MAX9790A 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 MAX9789A SPKR_INR LINE_OUTR PDISS(MAX) = HPR Figure 6. Mono Signal Output Configuration for MAX9789A Supply Bypassing The MAX9789A/MAX9790A 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. ______________________________________________________________________________________ 17 MAX9789A/MAX9790A Mono Speaker Configuration The MAX9789A 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 MAX9789A internal resistance. Headphone Amplifier Power-Supply Input (HPVDD and PVSS) 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. 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 8). 18 INPUT COUPLING CAPACITOR-INDUCED THD+N vs. FREQUENCY (HEADPHONE MODE) -50 -55 0402 6.3V X5R 10% 1μF -60 THD+N (dB FS) MAX9789A/MAX9790A Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers 0603 10V X5R 10% 1μF -65 -70 -75 -80 0805 25V X7R 10% 1μF 1206 25 X7R 10% 1μF VOUT = 3dB FS FS = 1VRMS RL = 32Ω -85 -90 10 100 1000 FREQUENCY (Hz) Figure 8. Input Coupling Capacitor-Induced THD 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. ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers CPVDD Bypass Capacitor (C3) The CPVDD bypass capacitor (C3) lowers the output impedance of the power supply and reduces the impact of the MAX9789A/MAX9790A’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. 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 MAX9789A/MAX9790A 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. ______________________________________________________________________________________ 19 MAX9789A/MAX9790A 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. Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A Block Diagrams 4.5V TO 5.5V 0.1μF PVDD 8, 18 MAX9789A 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 GAIN2 32 GAIN1 31 1.0μF LDO_EN VDD 1.0μF 1.0μF LDO_SET LDO_OUT 1.0μF 1.0μF 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 20 15 HPR 17 HPVDD 9 CPVDD 3V TO 5.5V CONTROL 10 C1P 11 CPGND 12 C1N C3 10μF 4 30 CHARGE PUMP 0.1μF TO CODEC HPL TO PVSS 3V TO 5.5V 4.5V TO 5.5V 16 1 LDO BLOCK 29 28 GND 5, 21 PGND 14 13 PVSS CPVSS C2 1.0μF ______________________________________________________________________________________ C1 1μF Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers 4.5V TO 5.5V 0.1μF 0.1μF VDD 30 PVDD 8, 18 MAX9790A 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 17 HPVDD 9 CPVDD TO PVSS 3V TO 5.5V HP_EN 22 MUTE 25 SPKR_EN 23 GAIN2 32 GAIN1 31 CONTROL 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 5, 21 PGND 14 13 PVSS CPVSS 10 C1P 11 CPGND 12 C1N 3V TO 5.5V C3 10μF C1 1μF C2 1.0μF ______________________________________________________________________________________ 21 MAX9789A/MAX9790A Block Diagrams (continued) Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A System Diagrams 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+ HP_L 4Ω HP_INR CIN 1μF OUTR- HP_INL HPL 5.0V MONO DGND 4Ω OUTL- SPKR_INL CIN 1μF SPKR_R HDA CODEC HP_R OUTL+ MAX9789A 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 REG 0.47μF 0.01μF 22 CHOLD PGND AGND ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers +5V 1μF 1μF +3.3V 10μF 0.1μF VDD VLDO_OUT PVDD HPVDD OUTL+ 1μF OUTL- SPKR_INL SPKR_L 1μF SPKR_R HDA CODEC HP1_R SPKR_INR OUTR+ 1μF HP_INR OUTR- 1μF HP1_L HP_INL HP1 HPL +3.3V MAX9789A 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 PGND 1μF ______________________________________________________________________________________ 23 MAX9789A/MAX9790A System Diagrams (continued) Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers HPVDD 17 PVDD 18 OUTR- 19 OUTR+ HPVDD 20 PGND PVDD 21 HP_EN OUTR- 22 SPKR_EN OUTR+ 23 BIAS PGND 24 SPKR_EN BIAS TOP VIEW HP_EN 24 23 22 21 20 19 18 17 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 CPVSS 13 CPVSS 12 C1N 11 CPGND 10 C1P 9 CPVDD 6 7 8 PVDD SPKR_INL 5 OUTL- SPKR_INR 4 OUTL+ 3 PGND 2 LDO_EN 1 LDO_SET GAIN2 32 N.C. 29 CPGND VDD 30 10 C1P GAIN1 31 9 CPVDD GAIN2 32 EP* + 1 2 3 4 5 6 7 8 PVDD EP* + C1N 11 OUTL- GAIN1 31 12 OUTL+ VDD 30 MAX9790A GND LDO_OUT 29 GND 28 PGND MAX9789A SPKR_INL GND 28 N.C. MUTE 25 SPKR_INR MAX9789A/MAX9790A Pin Configurations TQFN TQFN *EP = EXPOSED PADDLE *EP = EXPOSED PADDLE Simplified Block Diagrams (continued) SPEAKER SUPPLY 4.5V TO 5.5V Chip Information PROCESS: BiCMOS HEADPHONE SUPPLY 3.0V TO 5.5V MAX9790A SPKR_INR SPKR_INL HP_INR HP_INL SPKR_EN HP_EN MUTE GAIN1 GAIN2 24 ______________________________________________________________________________________ Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers QFN THIN.EPS ______________________________________________________________________________________ 25 MAX9789A/MAX9790A Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) MAX9789A/MAX9790A Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) 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. 26 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2006 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.