EVALUATION KIT AVAILABLE MAX98358 PDM Input Class D Audio Power Amplifier General Description The MAX98358 is a digital pulse-density modulated (PDM) input Class D power amplifier that provides Class AB audio performance with Class D efficiency. This IC offers five selectable gain settings (3dB, 6dB, 9dB, 12dB, and 15dB) set by a single gain-select input (GAIN). The IC can be configured to produce a left channel, right channel, or (left/2 + right/2) output from the stereo input data. The MAX98358 takes a stereo pulse density modulated (SPDM) input signal directly into the DAC. Data on the rising edge of PDM_CLK is considered left-channel data while data on the falling PDM_CLK edge is right channel. A mono sum feature is also implemented with SPDM data input by summing the data from both rising and falling clock edges. Active emissions-limiting, edge-rate limiting, and overshoot control circuitry greatly reduce EMI. A filterless spread-spectrum modulation scheme eliminates the need for output filtering found in traditional Class D devices and reduces the component count of the solution. Features Single-Supply Operation (2.5V to 5.5V) 3.2W Output Power into 4 at 5V 1.8mA Quiescent Current (VDD = 3.7V) 92% Efficiency (RL = 8, POUT = 1.5W) 29VRMS Output Noise (AV = 6dB) Low 0.015% THD+N at 1kHz Supported PDM_CLK Rates of 1.84MHz-4.32MHz and 5.28MHz-8.64MHz Supports Left, Right, or Left/2 + Right/2 Outputs Sophisticated Edge Rate Control Enables Filterless Class D Outputs 77dB PSRR at 217Hz Low RF Susceptibility Rejects TDMA Noise from GSM Radios Extensive Click-and-Pop Reduction Circuitry Robust Short-Circuit and Thermal Protection The IC is available in 9-pin WLP (1.345mm x 1.435mm x 0.64mm) and 16-pin TQFN (3mm x 3mm x 0.75mm) packages and is specified over the -40C to +85C temperature range. Available in Space-Saving Packages: 1.345mm x 1.435mm WLP (0.4mm Pitch) 3mm x 3mm TQFN Applications Simplified Block Diagram Notebook and Netbook Computers Cellular Phones Tablets Portable Media Players Ordering Information and Functional Diagram appears at end of data sheet. PDM INPUT 19-6786; Rev 5; 8/17 SHUTDOWN AND CHANNEL SELECT MAX98358 GAIN CONTROL DIGITAL AUDIO INTERFACE DAC CLASS D OUTPUT STAGE MAX98358 PDM Input Class D Audio Power Amplifier TABLE OF CONTENTS General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Simplified Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Package Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Speaker Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Bump/Pin Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Bump/Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Detailed Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Digital Audio Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Supported PDM_CLK Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 PDM_CLK Jitter Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 PDM Timing Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Standby Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 SD_MODE Pin and Shutdown Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Class D Speaker Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Ultra-Low EMI Filterless Output Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Speaker Current Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Gain Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Click-and-Pop Suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Filterless Class D Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Power-Supply Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Layout and Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 WLP Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Functional Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 www.maximintegrated.com Maxim Integrated 2 MAX98358 PDM Input Class D Audio Power Amplifier LIST OF FIGURES Figure 1. PDM Audio Interface Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 2. PDM Digital Audio Interface Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 3. SD_MODE Resistor Connection Using Open-Drain Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 4. SD_MODE Resistor Connection Using Push-Pull Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 5. EMI with 12in of Speaker Cable and No Output Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 6. Left-Channel Operation with 6dB Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 8. Right-Channel Operation with 6dB Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 7. Left-Channel Operation with 12dB Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 9. Stereo Operation Using Two MAX98358s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Figure 10. Monomix (Left/2 + Right/2) PDM Operation with 6dB Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 11. MAX98358 WLP Ball Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 LIST OF TABLES Table 1. PDM_CLK Channel Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 2. PDM_CLK Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 3. Calculated PDM_CLK Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 4. RMS Jitter Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 5. SD_MODE Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 6. Examples of SD_MODE Pullup Resistor Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 7. Gain Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 www.maximintegrated.com Maxim Integrated 3 MAX98358 PDM Input Class D Audio Power Amplifier Absolute Maximum Ratings VDD, PDM_CLK and PDM_DATA to GND...............-0.3V to +6V All Other Pins to GND............................... -0.3V to (VDD + 0.3V) Continuous Current In/Out of VDD/GND/OUT_...................1.6A Continuous Input Current (all other pins)..........................20mA Duration of OUT_ Short Circuit to GND or VDD.........Continuous Duration of OUTP Short to OUTN..............................Continuous Continuous Power Dissipation ...............................(TA = +70C) WLP (derate 13.7mW/C above +70C)....................1096mW TQFN (derate 20.8mW/C above +70C)..................1666mW Junction Temperature......................................................+150C Operating Temperature Range........................... -40C to +85C Storage Temperature Range............................. -65C to +150C Soldering Temperature (reflow).......................................+260C Lead Temperature (soldering, 10s, TQFN)......................+300C 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. Package Thermal Characteristics (Note 1) WLP Junction-to-Ambient Thermal Resistance (JA)...........73C/W Junction-to-Case Thermal Resistance (JC)................50C/W TQFN Junction-to-Ambient Thermal Resistance (JA)...........48C/W Junction-to-Case Thermal Resistance (JC)..................7C/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. Electrical Characteristics (VDD = 5V, VGND = 0V, GAIN = VDD (+6dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, ZSPK = , TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 2) PARAMETER SYMBOL Supply Voltage Range VDD Undervoltage Lockout UVLO Quiescent Current IDD Shutdown Current ISHDN Standby Current ISTNDBY CONDITIONS MAX UNITS 5.5 V 1.8 2.3 V TA = +25C 2.2 2.7 TA = +25C, VDD = 3.7V 1.8 2.2 SD_MODE = 0V, TA = +25C 0.6 2 A SD_MODE = 1.8V, no PDM_CLK, TA = +25C 340 400 A Guaranteed by PSSR test MIN TYP 2.5 1.4 mA Turn-On Time tON Time from receipt of first clock cycle to full operation 0.6 0.7 ms Output Offset Voltage VOS TA = +25C, gain = 15dB 0.3 2.5 mV -72 KCP Peak voltage, TA = Into shutdown +25C, A-weighted, 32 samples per Out of shutdown second (Note 3) Click-and-Pop Level VDD = 2.5V to 5.5V, TA = +25C Power-Supply Rejection Ratio www.maximintegrated.com PSRR TA = +25C (Notes 3, 4) dBV -66 60 75 f = 217Hz, 200mVP-P ripple 77 f = 10kHz, 200mVP-P ripple 60 dB Maxim Integrated 4 MAX98358 PDM Input Class D Audio Power Amplifier Electrical Characteristics (continued) (VDD = 5V, VGND = 0V, GAIN = VDD (+6dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, ZSPK = , TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 2) PARAMETER SYMBOL CONDITIONS THD+N 10% Output Power (Note 3) POUT THD+N = 1% Total Harmonic Distortion + Noise THD+N 3.2 ZSPK = 8 + 68H 1.8 ZSPK = 8 + 68H, VDD = 3.7V 0.93 ZSPK = 4 + 33H 2.5 ZSPK = 8 + 68H 1.4 ZSPK = 8 + 68H, VDD = 3.7V 0.77 f = 1kHz, POUT = 1W, TA = +25C, ZSPK = 4 + 33H (WLP) 0.02 f = 1kHz, POUT = 1W, TA = +25C, ZSPK = 4 + 33H (TQFN) 0.02 f = 1kHz, POUT = 0.5W, TA = +25C, ZSPK = 8 + 68FH 0.013 99 DR A-weighted, PDM_CLK = 6.144MHz, VRMS = 2.54V Output Noise VN A-weighted (Note 4) AV Current Limit ILIM Efficiency h MAX 0.06 % dB 29 VRMS 14.4 15 15.6 GAIN = GND 11.4 12 12.6 GAIN = unconnected 8.4 9 9.6 GAIN = VDD 5.4 6 6.6 GAIN = VDD through 100k 2.4 3 3.6 ZSPK = 8 + 68H, THD+N = 10%, f = 1kHz, gain = 12dB Frequency Response fOSC Spread-Spectrum Bandwidth UNITS W GAIN = GND through 100k DAC Gain Error Class D Oscillator Frequency TYP ZSPK = 4 + 33H Dynamic Range Gain (Relative to a 2.1dBV Reference Level) MIN dB 2.8 A 92 % 1 % 0.5 dB 330 kHz 20 kHz DIGITAL AUDIO INTERFACE PDM_CLK High Frequency Range fCLKH 5.28 8.64 MHz PDM_CLK Low Frequency Range fCLKL 1.84 4.32 MHz PDM_CLK High Time tPDM_CLKH 40 ns PDM_CLK Low Time tPDM_CLKL 40 ns Maximum Low-Frequency PDM_CLK Jitter RMS jitter below 40kHz 0.5 ns Maximum Low-Frequency PDM_CLK Jitter RMS jitter above 40kHz 12 ns www.maximintegrated.com Maxim Integrated 5 MAX98358 PDM Input Class D Audio Power Amplifier Electrical Characteristics (continued) (VDD = 5V, VGND = 0V, GAIN = VDD (+6dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, ZSPK = , TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 2) PARAMETER SYMBOL CONDITIONS Input High Voltage VIH Digital audio inputs Input Low Voltage VIL Digital audio inputs Input Leakage Current IIH, IIL Input Capacitance VIN = 0V, VDD = 5.5V, TA = +25C MIN PDM_DATA to PDM_CLK Setup Time tSETUP PDM_DATA to PDM_CLK Hold Time tHOLD MAX 1.3 UNITS V -1 CIN PDM Ones Density TYP 0.6 V +1 A 3 Maximum 75 Minimum 25 pF % 10 ns 10 SD_MODE COMPARATOR TRIP POINTS B0 See SD_MODE and shutdown operation for details B1 B2 SD_MODE Pulldown Resistor RPD 0.08 0.16 0.355 0.65 0.77 0.825 1.245 1.4 1.5 92 100 108 V k GAIN COMPARATOR TRIP POINTS VGAIN AV = 3dB gain 0.65 x VDD 0.85 x VDD AV = 6dB gain 0.9 x VDD VDD AV = 9dB gain 0.4 x VDD 0.6 x VDD AV = 12dB gain 0 0.1 x VDD AV = 15dB gain 0.15 x VDD 0.35 x VDD V Note 2: 100% production tested at TA = +25C. Specifications over temperature limits are guaranteed by design. Note 3: Class D amplifier testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For RL = 8, LL = 68H. For RL = 4, LL = 33H. Note 4: Digital silence used for input signal. Note 5: Dynamic range is measured using the EIJA method. -60dbFS 1kHz output signal. A-weighted and normalized to 0dBFS. f = 20Hz to 20kHz. www.maximintegrated.com Maxim Integrated 6 MAX98358 PDM Input Class D Audio Power Amplifier tPDM_CLK tPDM_CLKH tPDM_CLKL PDM_CLK tSETUP LEFT PDM_DATA tHOLD tSETUP RIGHT tHOLD LEFT RIGHT Figure 1. PDM Audio Interface Timing Diagram Typical Operating Characteristics (VDD = 5V, VGND = 0V, GAIN = GND (12dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) QUIECENT CURRENT vs. SUPPLY VOLTAGE 4.0 VDDIO = 1.8V 3.0 2.5 2.0 1.5 1.0 0.5 0.0 -10 2.5 3.0 3.5 4.0 4.5 SUPPLY VOLTAGE (V) 0.7 0.6 0.5 0.4 0.3 0.2 5.0 0.0 5.5 2.5 3.0 3.5 4.0 4.5 SUPPLY VOLTAGE (V) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER toc03 0 VDD = 3.7V ZSPK = 8 + 68H -10 -20 toc04 5.0 0 VDD = 4.2V ZSPK = 8 + 68H -10 -20 -30 -30 -40 -40 -40 -50 -60 6kHz -70 -80 -90 -100 0.001 -50 -60 THDN (dB) -30 THDN (dB) THDN (dB) -20 0.8 0.1 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER 0 6kHz -70 1kHz -80 100Hz 0.01 0.1 1 OUTPUT POWER (W) www.maximintegrated.com toc02 VDDIO = 1.8V 0.9 SHUTDOWN CURRENT (A) QUIECENT CURRENT (mA) 3.5 SHUTDOWN CURRENT vs. SUPPLY VOLTAGE 1.0 toc01 -90 10 -100 0.001 5.5 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER toc05 VDD = 5V ZSPK = 8 + 68H -50 -60 6kHz -70 1kHz -80 100Hz 0.01 0.1 1 OUTPUT POWER (W) -90 10 -100 0.001 1kHz 100Hz 0.01 0.1 1 OUTPUT POWER (W) 10 Maxim Integrated 7 MAX98358 PDM Input Class D Audio Power Amplifier Typical Operating Characteristics (continued) (VDD = 5V, VGND = 0V, GAIN = GND (12dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER 0 VDD = 3.7V ZSPK = 4 + 33H -10 -20 toc07 -20 -30 -40 -40 -40 6kHz -50 -70 -80 -80 -100 0.001 100Hz -100 0.001 10 VDD = 3.7V ZSPK = 8 + 68H -10 -20 -20 THD+N RATIO(dB) -40 -50 -60 POUT = 75mW -70 0.01 0.1 1 OUTPUT POWER (W) -50 POUT = 100mW -70 POUT = 350mW -90 10 100 1000 10000 FREQUENCY (Hz) www.maximintegrated.com 100000 -100 VDD = 5V ZSPK = 8 + 68H -30 -40 -50 -60 POUT = 850mW -70 -80 POUT = 500mW -90 10 100 POUT = 150mW -90 1000 10000 FREQUENCY (Hz) 100000 10 toc11 0 -20 -40 0.01 0.1 1 OUTPUT POWER (W) 100Hz TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT FREQUENCY -10 -80 -80 -100 0.001 10 -30 -60 1kHz -90 VDD = 4.2V ZSPK = 8 + 68H -10 -30 -100 0 toc09 6kHz -60 -80 100Hz TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT FREQUENCY toc10 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT FREQUENCY 0 1kHz -90 0.01 0.1 1 OUTPUT POWER (W) -50 -70 THD+N RATIO(dB) 1kHz 6kHz -60 -70 THDN (dB) -30 -60 VDD = 5V ZSPK = 4 + 33H -10 -30 -50 toc08 0 VDD = 4.2V ZSPK = 4 + 33H -20 -90 THD+N RATIO(dB) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER -10 THDN (dB) THDN (dB) 0 toc06 -100 10 100 1000 10000 FREQUENCY (Hz) 100000 Maxim Integrated 8 MAX98358 PDM Input Class D Audio Power Amplifier Typical Operating Characteristics (continued) (VDD = 5V, VGND = 0V, GAIN = GND (12dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) THD+N RATIO(dB) THD+N RATIO(dB) -20 -40 -50 -60 POUT = 150mW -70 POUT = 600mW -90 10 100 -50 POUT = 250mW -70 10000 -100 100000 10 100 OUTPUT POWER vs. LOAD RESISTANCE 2.5 VDD = 3.7V OUTPUT POWER (W) OUTPUT POWER (W) 1.5 10% THD+N 1.0 1% THD+N 0.5 100000 toc16 10 LOAD RESISTANCE www.maximintegrated.com 100 POUT = 1.5W -70 POUT = 350mW 10 100 1000 10000 FREQUENCY (Hz) OUTPUT POWER vs. LOAD RESISTANCE 4.5 100000 toc18 VDD = 5V 3.5 2.0 10% THD+N 1.5 1% THD+N 1.0 3.0 2.5 10% THD+N 2.0 1% THD+N 1.5 1.0 0.5 1 -60 4.0 2.5 0.0 -50 -100 VDD = 4.2V 3.0 2.0 0.0 OUTPUT POWER vs. LOAD RESISTANCE 3.5 toc15 -40 -90 1000 10000 FREQUENCY (Hz) FREQUENCY (Hz) -30 -80 POUT = 850mW -90 1000 -20 -40 -60 VDD = 5V ZSPK = 4 + 33H -10 -30 -80 -80 -100 VDD = 4.2V ZSPK = 4 + 33H -10 -30 0 THD+N RATIO(dB) VDD = 3.7V ZSPK = 4 + 33H -20 toc13 0 OUTPUT POWER (W) 0 -10 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT FREQUENCY toc14 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT FREQUENCY toc12 0.5 1 10 LOAD RESISTANCE 100 0.0 1 10 LOAD RESISTANCE 100 Maxim Integrated 9 MAX98358 PDM Input Class D Audio Power Amplifier Typical Operating Characteristics (continued) (VDD = 5V, VGND = 0V, GAIN = GND (12dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) 2.5 4.0 toc18 ZSPK = 8 + 68H 1.5 OUTPUT POWER (W) THD+N = 10% 1.0 THD+N = 1% 0.5 THD+N = 10% 2.5 2.0 THD+N = 1% 1.5 1.0 3.0 3.5 4.0 4.5 5.0 0.0 5.5 2.5 3.0 SUPPLY VOLTAGE (V) EFFICIENCY vs. OUTPUT POWER 100 VDD = 3.7V 80 VDD = 4.2V VDD = 5V 4.0 4.5 5.0 EFFICIENCY vs. OUTPUT POWER 50 40 30 toc22 VDD = 4.2V 60 VDD = 5V 50 40 30 10 ZSPK = 8 + 68H 0.5 1.0 1.5 OUTPUT POWER (W) www.maximintegrated.com 10 2.0 0.20 0.18 VDD = 3.7V 20 20 0.0 -1 -3 5.5 ZSPK = 8 + 68H 70 EFFICIENCY (%) EFFICIENCY (%) 3.5 80 60 0 100 toc21 70 10 0 100 SUPPLY VOLTAGE (V) 90 90 1 -2 0.5 2.5 toc20 NORMALIZED TO 1kHz 2 0 0.0001 1000 10000 FREQUENCY (Hz) POWER DISSIPATION vs. OUTPUT POWER 100000 toc23 ZSPK = 8 + 68H 0.16 POWER DISSIPATION (W) OUTPUT POWER (W) 3.0 NORMALIZED GAIN vs. FREQUENCY 3 toc19 ZSPK = 4 + 33H 3.5 2.0 0.0 OUTPUT POWER vs. SUPPLY VOLTAGE NORMALIZED GAIN (dB) OUTPUT POWER vs. SUPPLY VOLTAGE 0.14 VDD = 5V 0.12 0.10 0.08 0.06 0.04 VDD = 4.2V VDD = 3.7V 0.02 0.001 0.01 0.1 OUTPUT POWER (W) 1 0.00 0.001 0.01 0.1 1 OUTPUT POWER (W) 10 Maxim Integrated 10 MAX98358 PDM Input Class D Audio Power Amplifier Typical Operating Characteristics (continued) (VDD = 5V, VGND = 0V, GAIN = GND (12dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) 100 100 toc24 80 VDD = 3.7V 60 50 40 30 VDD = 4.2V 50 VDD = 5V 40 30 0 1 2 OUTPUT POWER (W) 3 0.001 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY toc27 VDD = 5V 0.35 0.30 VDD = 4.2V 0.25 0.20 0.15 0.10 0.01 0.1 0.00 0.001 1 OUTPUT POWER (W) POWER-SUPPLY REJECTION RATIO vs. SUPPLY VOLTAGE toc28 100 VDD = 3.7V 0.01 0.1 1 OUTPUT POWER (W) TURN-ON RESPONSE 60 60 PSRR (dB) 70 50 40 50 40 30 30 20 20 10 100 SD_MODE 1V/div 10 ZSPK = 8 + 68H 10 toc29 OUTPUT 1V/div 80 70 10 ZSPK = 8 + 68H 90 80 toc26 ZSPK = 4 + 33H 0.05 0 0.0001 90 PSRR (dB) VDD = 3.7V 60 10 ZSPK = 4 + 33H POWER DISSIPATION vs. OUTPUT POWER 0.40 20 100 0 0.45 70 20 10 0.50 80 VDD = 5V EFFICIENCY (%) EFFICIENCY (%) 70 VDD = 4.2V toc25 ZSPK = 4 + 33H 90 90 0 EFFICIENCY vs. OUTPUT POWER POWER DISSIPATION (W) EFFICIENCY vs. OUTPUT POWER 1000 FREQUENCY (Hz) www.maximintegrated.com 10000 100000 0 2.50 3.00 3.50 4.00 4.50 SUPPLY VOLTAGE (V) 5.00 5.50 2ms/div Maxim Integrated 11 MAX98358 PDM Input Class D Audio Power Amplifier Typical Operating Characteristics (continued) (VDD = 5V, VGND = 0V, GAIN = GND (12dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) INBAND OUTPUT SPECTRUM 20 toc30 -20 AMPLITUDE (dBV) -40 -60 -80 1ms/div -40 -60 -80 -100 -100 -120 -120 -140 0 5000 10000 15000 -140 20000 0 5000 FREQUENCY (Hz) INBAND OUTPUT SPECTRUM 20 fPDMCLK = 6.144MHz ZSPK = 8 + 68H 0 toc34 0 -60 -80 -40 -60 -80 -40 -60 -80 -100 -100 -120 -120 -120 -140 -140 5000 10000 15000 FREQUENCY (Hz) www.maximintegrated.com 20000 toc35 fPDMCLK = 5.6448MHz ZSPK = 8 + 68H 0 -100 0 20000 -20 AMPLITUDE (dBV) AMPLITUDE (dBV) -40 10000 15000 FREQUENCY (Hz) INBAND OUTPUT SPECTRUM 20 fPDMCLK = 5.6448MHz ZSPK = 8 + 68H -20 -20 AMPLITUDE (dBV) INBAND OUTPUT SPECTRUM 20 toc33 toc32 fPDMCLK = 6.144MHz ZSPK = 8 + 68H 0 -20 SD_MODE 1V/div INBAND OUTPUT SPECTRUM 20 fPDMCLK = 6.144MHz ZSPK = 8 + 68H 0 OUTPUT 1V/div toc31 AMPLITUDE (dBV) TURN-OFF RESPONSE 0 5000 10000 15000 FREQUENCY (Hz) 20000 -140 0 5000 10000 15000 FREQUENCY (Hz) 20000 Maxim Integrated 12 MAX98358 PDM Input Class D Audio Power Amplifier Typical Operating Characteristics (continued) (VDD = 5V, VGND = 0V, GAIN = GND (12dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) INBAND OUTPUT SPECTRUM 20 fPDMCLK = 5.6448MHz ZSPK = 8 + 68H 0 -60 -80 -20 -40 -60 -80 -40 -60 -80 -100 -100 -100 -120 -120 -120 -140 -140 0 5000 10000 15000 FREQUENCY (Hz) INBAND OUTPUT SPECTRUM 20 20000 5000 10000 15000 INBAND OUTPUT SPECTRUM 20 fPDMCLK = 3.072MHz ZSPK = 8 + 68H 0 0 -140 20000 toc40 -80 -40 -60 -80 -60 -80 -100 -100 -120 -120 -140 -140 FREQUENCY (Hz) www.maximintegrated.com 20000 toc41 -40 -120 15000 20000 fPDMCLK = 2.8224MHz ZSPK = 8 + 68H 0 -100 10000 15000 -20 AMPLITUDE (dBV) -60 10000 INBAND OUTPUT SPECTRUM 20 fPDMCLK = 2.8224MHz ZSPK = 8 + 68H 0 AMPLITUDE (dBV) -40 5000 5000 FREQUENCY (Hz) -20 -20 0 0 FREQUENCY (Hz) toc39 toc38 fPDMCLK = 3.072MHz ZSPK = 8 + 68H 0 AMPLITUDE (dBV) -40 INBAND OUTPUT SPECTRUM 20 -20 AMPLITUDE (dBV) AMPLITUDE (dBV) toc37 fPDMCLK = 3.072MHz ZSPK = 8 + 68H 0 -20 AMPLITUDE (dBV) INBAND OUTPUT SPECTRUM 20 toc36 0 5000 10000 15000 FREQUENCY (Hz) 20000 -140 0 5000 10000 15000 FREQUENCY (Hz) 20000 Maxim Integrated 13 MAX98358 PDM Input Class D Audio Power Amplifier Typical Operating Characteristics (continued) (VDD = 5V, VGND = 0V, GAIN = GND (12dB). PDM_CLK = 3.072MHz, speaker loads (ZSPK) connected between OUTP and OUTN, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) INBAND OUTPUT SPECTRUM 20 toc42 fPDMCLK = 2.8224MHz ZSPK = 8 + 68H 0 -20 AMPLITUDE (dBV) AMPLITUDE (dBV) -40 -60 -80 -40 -60 -80 -100 -100 -120 -120 0 5000 10000 15000 -140 20000 0 5000 FREQUENCY (Hz) INBAND OUTPUT SPECTRUM 20 toc44 AMPLITUDE (dBV) AMPLITUDE (dBV) toc45 -20 -40 -60 -80 -40 -60 -80 -100 -100 -120 -120 0 5000 10000 FREQUENCY (Hz) www.maximintegrated.com 20000 fPDMCLK = 2.048MHz ZSPK = 8 + 68H 0 -20 10000 15000 FREQUENCY (Hz) INBAND OUTPUT SPECTRUM 20 fPDMCLK = 2.048MHz ZSPK = 8 + 68H 0 -140 toc43 fPDMCLK = 2.048MHz ZSPK = 8 + 68H 0 -20 -140 INBAND OUTPUT SPECTRUM 20 15000 20000 -140 0 5000 10000 15000 FREQUENCY (Hz) 20000 Maxim Integrated 14 MAX98358 PDM Input Class D Audio Power Amplifier OUTP + OUTN TOP VIEW MAX98358 GND TOP VIEW BUMP SIDE DOWN N.C. Bump/Pin Configurations 12 11 10 9 SD_MODE VDD OUTP A1 A2 A3 N.C. 13 8 VDD PDM_DATA GAIN OUTN GND 14 7 VDD B1 B2 B3 6 N.C. PDM_CLK GND GND C1 C2 C3 5 N.C. MAX98358 GND 15 3 TQFN 4 SD_MODE 2 GND 1 GAIN WLP + PDM_DATA PDM_CLK 16 Bump/Pin Description BUMP PIN WLP TQFN A1 4 SD_MODE A2 7, 8 VDD A3 9 B1 1 NAME OUTP FUNCTION Shutdown and Channel Select. Determines left, right, or (left/2 + right/2) mix and also used for shutdown. See Table 5. Power-Supply Input Positive Speaker Amplifier Output PDM_DATA Digital Input Signal Amplifier Gain B2 2 Gain Connections Gain (dB) GND through 100k resistor 15 GAIN GND 12 Unconnected 9 VDD 6 VDD through 100k resistor 3 B3 10 OUTN C1 16 PDM_CLK C2, C3 3, 11, 14, 15 GND Ground -- 5, 6, 12, 13 N.C. No Connection -- -- EP www.maximintegrated.com Negative Speaker Amplifier Output PDM Bit Clock Input Signal. Supports frequency ranges: 1.84MHz-4.32MHz and 5.28 MHz- 8.64MHz. Exposed Pad. The exposed pad is not internally connected. Connect the exposed pad to a solid ground plane for thermal dissipation. Maxim Integrated 15 MAX98358 PDM Input Class D Audio Power Amplifier Detailed Description The output stage features low-quiescent current, comprehensive click-and-pop suppression, and excellent RF immunity. The IC offers Class AB audio performance with Class D efficiency in a minimal board-space solution. The Class D amplifier features spread-spectrum modulation with edge-rate and overshoot control circuitry that offers significant improvements in switch-mode amplifier radiated emissions. The amplifier features click-and-pop suppression that reduces audible transients on startup and shutdown. The amplifier includes thermal-overload and short-circuit protection. The MAX98358 is a digital PDM input Class D power amplifier. The PDM modulation scheme uses the relative density of digital pulses to represent the amplitude of an analog signal. The IC accepts stereo PDM data through PDM_DATA and PDM_CLK. SD_MODE selects which audio channel is output by the amplifier and is used to put the IC into shutdown. The GAIN pin offers five gain settings and allows the output of the amplifier to be tuned to the appropriate level. Digital Audio Interface The IC takes a stereo PDM input signal directly into the DAC. Data read on the rising edge of PDM_CLK is leftchannel data while data read on the falling PDM_CLK edge is right channel (Table 1). Table 1. PDM_CLK Channel Select PDM_CLK EDGE DIRECTION CHANNEL Rising edge Left Falling edge Right Supported PDM_CLK Rates Table 2 indicates the range of PDM_CLK rates that are supported by the IC. Table 3 indicates the specific clock rates to use based on the baseband rate and the oversample rate of the incoming PDM signal. Table 2. PDM_CLK Rates SUPPORTED CLOCK RATES (MHz) PDM_CLK Jitter Tolerance The IC features a very high PDM_CLK jitter tolerance of 0.5ns for RMS jitter below 40kHz and 12ns for wideband RMS jitter while maintaining a dynamic range greater than 98dB (Table 4). 1.84-4.32 5.28-8.64 Table 3. Calculated PDM_CLK Rates BASEBAND SAMPLE RATE (kHz) INPUT CLOCK RATES (MHz) 32x OVERSAMPLED PDM 64x OVERSAMPLED PDM 128x OVERSAMPLED PDM 256x OVERSAMPLED PDM 8 -- -- -- 2.048 16 -- -- 2.048 4.096 32 -- 2.048 4.096 -- 44.1 -- 2.8224 5.6448* -- 48 -- 3.072 6.144* -- 88.2 2.8224 5.6448* -- -- 96 3.072 6.144* -- -- *The mono left/2 + right/2 feature is not supported at PDM_CLK rates of 5.28MHz and above. Table 4. RMS Jitter Tolerance FREQUENCY RMS JITTER TOLERANCE (ns) < 40kHz 0.5 40kHz-PDM_CLK 12 www.maximintegrated.com Maxim Integrated 16 MAX98358 PDM Input Class D Audio Power Amplifier SD_MODE Pin and Shutdown Operation PDM Timing Characteristics Figure 2 shows the PDM operation of the IC. The bitdepth is one bit and each bit alternates between leftchannel and right-channel data. The IC features a low-power shutdown mode, drawing less than 0.6A (typ) of supply current. During shutdown, all internal blocks are turned off, including setting the output stage to a high-impedance state. Drive SD_MODE low to put the IC into shutdown. If the PDM generator produces data that is stuck at logichigh or logic-low, then the output of the IC is railed, forcing DC at the load. Therefore, it is recommended that the PDM generator includes protection to detect this invalid condition. If such a condition is detected, then the IC should either be put into shutdown or PDM_CLK should be stopped. The state of SD_MODE determines the audio channel that is sent to the amplifier output (Table 5). Drive SD_MODE high to select the left channel of the stereo input data. Drive SD_MODE high through a sufficiently small resistor to select the right channel of the stereo input data. Drive SD_MODE high through a sufficiently large resistor to select monomix mode where both the left and right words of the stereo input data are summed (left/2 + right/2). The monomix (left/2 + right/2) mode is not supported for PDM_CLK rates 5.28MHz. and above. RLARGE and RSMALL are determined by the VDDIO voltage (logic voltage from control interface) that is driving SD_MODE according to the following two equations: Standby Mode The MAX98358 automatically enters standby mode when PDM_CLK is removed. In standby mode, the Class D speaker amplifier is turned off and the outputs go into a high-impedance state, ensuring that the unwanted current is not transferred to the load during this condition. Standby mode should not be used in place of the shutdown mode because the shutdown mode provides the lowest power consumption and the best power-on/off click-and-pop performance. RSMALL (k) = 94.0 x VDDIO - 100 RLARGE (k) = 222.2 x VDDIO - 100 SD_MODE = LOGIC-HIGH PDM_CLK PDM_DATA L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R L R RIGHT CHANNEL IGNORED SD_MODE = PULLUP THROUGH RSMALL PDM_CLK PDM_DATA L R L R L R L R L R L R L R L R L R LEFT CHANNEL IGNORED SD_MODE = PULLUP THROUGH RLARGE PDM_CLK PDM_DATA L R L R L R L R L R L R L R L R L R LEFT AND RIGHT CHANNELS AVERAGED Figure 2. PDM Digital Audio Interface Timing Table 5. SD_MODE Control SD_MODE STATUS SELECTED CHANNEL High VSD_MODE > B2 trip point Left Pullup through RSMALL B2 trip point (1.4V typ) > VSD_MODE > B1 trip point Right Pullup through RLARGE* B1 trip point (0.77V typ) > VSD_MODE > B0 trip point (Left/2 + right/2) Low B0 trip point (0.16V typ) > VSD_MODE Shutdown www.maximintegrated.com Maxim Integrated 17 MAX98358 Figure 3 and Figure 4 show how to connect an external resistor to SD_MODE when using an open-drain driver or a pullup/down driver. When the device is configured in left channel mode (SD_MODE is directly driven to logic-high by the control interface) care must be taken to avoid violating the Absolute Maximum Ratings limits for SD_MODE. Ensuring that VDD is always greater than VDDIO is one way to prevent SD_MODE from violating the Absolute Maximum Ratings limits. If this is not possible in the application (e.g., if VDD < 3.0V and VDDIO = 3.3V), then it is necessary to add a small resistance (~2k) in series with SD_MODE to limit the current into the SD_MODE pin. This is not a concern when using the right channel or monomix modes. Class D Speaker Amplifier The filterless Class D amplifier offers much higher efficiency than Class AB amplifiers. The high efficiency of a Class D amplifier is due to the switching operation of the output stage transistors. Any power loss associated with the Class D output stage is mostly due to the I2R loss of the MOSFET on-resistance and quiescent current overhead. Ultra-Low EMI Filterless Output Stage Traditional Class D amplifiers require the use of external LC filters, or shielding, to meet EN55022B electromagnetic-interference (EMI) regulation standards. Maxim's active emissions-limiting edge-rate control circuitry and spreadspectrum modulation reduces EMI emissions while maintaining up to 92% efficiency. Maxim's spread-spectrum modulation mode flattens wideband spectral components while proprietary techniques ensure that the cycle-to-cycle variation of the switching period does not degrade audio reproduction or efficiency. The ICs' spread-spectrum modulator randomly varies the switching frequency by 20kHz around the center frequency (330kHz). Above 10MHz, the wideband spectrum looks like noise for EMI purposes (Figure 5). Speaker Current Limit If the output current of the speaker amplifier exceeds the current limit (2.8A typ), the IC disables the outputs for approximately 100s. At the end of the 100s, the outputs are re-enabled. If the fault condition still exists, the IC continues to disable and re-enable the outputs until the fault condition is removed. www.maximintegrated.com PDM Input Class D Audio Power Amplifier Gain Selection The IC offers five programmable gain selections through a singel gain input (GAIN). Gain is referenced to the full-scale output of the DAC, which is 2.1dBV (Table 7). Assuming that the desired output swing is not limited by the supply voltage rail, the IC's output level can be calculated based on the PDM input ones's density and selected amplifier gain according to the following equation: Output signal level (dBV) = 20 x log[abs(PDM one's density(%) - 50) /25] (dBFS) + 2.1dB + selected speaker amplifier gain (dB) where the one's density of the PDM input ranges from 75% (maximum positive magnitude) to 25% (maximum negative magnitude). 0dFBS is referenced to 0dBV. Click-and-Pop Suppression The IC speaker amplifier features Maxim's comprehensive click-and-pop suppression. During startup, the click-and-pop suppression circuitry reduces audible transient sources internal to the device. To achieve optimal click-and-pop reduction at startup, it is recommended that idle data be sent to the digital audio interface for the first 0.5ms of turn-on time. When entering shutdown, the differential speaker outputs simultaneously drop to GND. Table 6. Examples of SD_MODE Pullup Resistor Values LOGIC VOLTAGE LEVEL (VDDIO) (V) RSMALL (k) RLARGE (k) 1.8 69.8 300 3.3 210 634 Table 7. Gain Selection GAIN GAIN (dB) Connect to GND through 100k 5% resistor 15 Connect to GND 12 Unconnected 9 Connect to VDD 6 Connect to VDD through 100k 5% resistor 3 Maxim Integrated 18 MAX98358 PDM Input Class D Audio Power Amplifier PROCESSOR VDDIO LEFT MODE MAX98358 R VSD_MODE GPIO 100k 8% B2 (1.4V typ) RIGHT MODE B1 (0.77V typ) LEFT/2 + RIGHT/2 MODE B0 (0.16V typ) Figure 3. SD_MODE Resistor Connection Using Open-Drain Driver PROCESSOR VDDIO GPIO LEFT MODE MAX98358 R VSD_MODE 100k 8% B2 (1.4V typ) RIGHT MODE B1 (0.77V typ) LEFT/2 + RIGHT/2 MODE B0 (0.16V typ) Figure 4. SD_MODE Resistor Connection Using Push-Pull Driver EMISSION LEVEL (dBV/m) 90 70 50 30 10 -10 0 100 200 300 400 500 600 700 800 900 1000 FREQUENCY (MHz) Figure 5. EMI with 12in of Speaker Cable and No Output Filtering www.maximintegrated.com Maxim Integrated 19 MAX98358 PDM Input Class D Audio Power Amplifier 2.5V TO 5.5V 2.5V TO 5.5V 10F 10F 0.1F CODEC GPIO* SD_MODE A1 A2 A3 PDM CLOCK PDM DATA OUT PDM_CLK PDM_DATA C1 GPIO* OUTP SD_MODE A1 VDD GAIN B2 A2 A3 MAX98358 B3 B1 CODEC VDD GAIN B2 0.1F PDM CLOCK OUTN PDM DATA OUT C2, C3 PDM_CLK PDM_DATA GND C1 MAX98358 B3 B1 OUTP OUTN C2, C3 GND *RESPONDS TO LEFT CHANNEL WHEN GPIO IS HIGH. THE MAX98358 IS SHUTDOWN WHEN GPIO IS LOW. *RESPONDS TO LEFT CHANNEL WHEN GPIO IS HIGH. THE MAX98358 IS SHUTDOWN WHEN GPIO IS LOW. Figure 6. Left-Channel Operation with 6dB Gain Figure 7. Left-Channel Operation with 12dB Gain 2.5V TO 5.5V 10F CODEC RSMALL (69.8k)** GPIO* PDM CLOCK PDM DATA OUT 0.1F VDD GAIN SD_MODE PDM_CLK A1 C1 PDM_DATA B1 B2 A2 A3 OUTP MAX98358 B3 OUTN C2, C3 GND *RESPONDS TO RIGHT CHANNEL WHEN GPIO IS HIGH. **69.8k ASSUMES VGPIO = 1.8V. THE MAX98358 IS SHUTDOWN WHEN GPIO IS LOW. Figure 8. Right-Channel Operation with 6dB Gain www.maximintegrated.com Maxim Integrated 20 MAX98358 PDM Input Class D Audio Power Amplifier 2.5V TO 5.5V 10F 0.1F VDD GAIN SD_MODE A1 B2 A2 A3 PDM_CLK PDM_DATA OUTP MAX98358 C1 B3 B1 OUTN C2 GND CODEC *RESPONDS TO LEFT CHANNEL WHEN GPIO IS HIGH. THE MAX98358 IS SHUTDOWN WHEN GPIO IS LOW. GPIO* 2.5V TO 5.5V PDM CLOCK 10F PDM DATA OUT RSMALL (69.8k)** 0.1F VDD GAIN SD_MODE A1 B2 A2 A3 PDM_CLK PDM_DATA C1 MAX98358 B3 B1 OUTP OUTN C2, C3 GND *RESPONDS TO RIGHT CHANNEL WHEN GPIO IS HIGH. **69.8k ASSUMES VGPIO = 1.8V. THE MAX98358 IS SHUTDOWN WHEN GPIO IS LOW. Figure 9. Stereo Operation Using Two MAX98358s www.maximintegrated.com Maxim Integrated 21 MAX98358 Filterless Class D Operation Traditional Class D amplifiers require an output filter to recover the audio signal from the amplifier's output. The filter adds cost, size, and decreases efficiency and THD+N performance. The MAX98358's filterless modulation scheme does not require an output filter. The device relies on the inherent inductance of the speaker coil and the natural filtering of both the speaker and the human ear to recover the audio component of the square-wave output. Because the switching frequency of the IC is well beyond the bandwidth of most speakers, voice coil movement due to the switching frequency is very small. Use a speaker with a series inductance > 10FH. Typical 8I speakers exhibit series inductances in the 20FH to 100FH range. Power-Supply Input VDD, which ranges from 2.5V to 5.5V, powers the IC, including the speaker amplifier. Bypass VDD with a 0.1FF and 10FF capacitor to GND. Some applications might require only the 10FF bypass capacitor, making it possible to operate with a single external component. Apply additional bulk capacitance at the IC if long input traces between VDD and the power source are used. Layout and Grounding Proper layout and grounding are essential for optimum performance. Good grounding improves audio performance and prevents switching noise from coupling into the audio signal. Use wide, low-resistance output traces. As load impedance decreases, the current drawn from the device outputs increases. At higher current, the resistance of the output traces decreases the power delivered to the load. For example, if 2W is delivered from the speaker output to a 4I load through 100mI of total speaker trace, 1.904W is being delivered to the speaker. If power is delivered through 10mI of total speaker trace, 1.951W is being delivered to the speaker. Wide output, supply, and ground traces also improve the power dissipation of the IC. Parasitic capacitance on the output causes higher quiescent current by VDD x 330kHz x CPARASITIC. For example, at VDD and a total parasitic capacitance of 100pF (50pF on each output trace), the increase in quiescent current is: 5 x 330kHz x 100pF = 165A. The IC is inherently designed for excellent RF immunity. For best performance, add ground fills around all signal traces on top or bottom PCB planes. www.maximintegrated.com PDM Input Class D Audio Power Amplifier WLP Applications Information For the latest application details on WLP construction, dimensions, tape carrier information, PCB techniques, bump-pad layout, and recommended reflow temperature profile, as well as the latest information on reliability testing results, refer to the Application Note 1891: Wafer-Level Packaging (WLP) and Its Applications. Figure 11 shows the dimensions of the WLP balls used on the IC. 2.5V TO 5.5V 10F CODEC GPIO* PDM CLOCK PDM DATA OUT RLARGE (300k)** SD_MODE 0.1F A1 VDD GAIN B2 A2 A3 PDM_CLK PDM_DATA C1 OUTP MAX98358 B3 B1 OUTN C2, C3 GND *LEFT AND RIGHT ARE SUMMED WHEN GPIO IS HIGH. **300k ASSUMES VGPIO = 1.8V. THE MAX98358 IS SHUTDOWN WHEN GPIO IS LOW. Figure 10. Monomix (Left/2 + Right/2) PDM Operation with 6dB Gain 0.24mm 0.21mm Figure 11. MAX98358 WLP Ball Dimensions Maxim Integrated 22 MAX98358 PDM Input Class D Audio Power Amplifier Functional Diagram 2.5V TO 5.5V 10F 0.1F VDD A2 (7, 8) C1 PDM_CLK (16) PDM_DATA B1 (1) SD_MODE A1 (3) GAIN B2 (2) MAX98358 DIGITAL AUDIO INTERFACE DAC (3, 11, 14, 15) C2, C3 CLASS D OUTPUT STAGE A3 (9) OUTP B3 (10) OUTN GND () APPLIES TO TQFN PACKAGE Ordering Information PART MAX98358EWL+T MAX98358ETE+ TEMP RANGE PIN-PACKAGE -40C to +85C -40C to +85C 9 WLP 16 TQFN +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. www.maximintegrated.com Maxim Integrated 23 MAX98358 PDM Input Class D Audio Power Amplifier Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.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 OUTLINE NO. LAND PATTERN NO. 9 WLP W91F1+1 21-0896 Refer to Application Note 1891 16 TQFN T1633+4 21-0136 90-0031 0.05 S 0.05 www.maximintegrated.com AB maxim integrated TM Maxim Integrated 24 MAX98358 PDM Input Class D Audio Power Amplifier Package Information (continued) For the latest package outline information and land patterns (footprints), go to www.maximintegrated.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. www.maximintegrated.com Maxim Integrated 25 MAX98358 PDM Input Class D Audio Power Amplifier Package Information (continued) For the latest package outline information and land patterns (footprints), go to www.maximintegrated.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. www.maximintegrated.com Maxim Integrated 26 MAX98358 PDM Input Class D Audio Power Amplifier Revision History REVISION NUMBER REVISION DATE PAGES CHANGED DESCRIPTION 0 9/13 Initial release -- 1 11/13 Removed future product reference 21 2 8/14 Added THD+N TQFN typical only spec to Electrical Characteristics table 3 3 1/15 Added Table of Contents, updated SSM spec, replaced all typical operating characteristics, and corrected typos 4 8/15 Corrected package outline for WLP package 24 8/17 Updated soldering temperature and added lead temperature in the Absolute Maximum Ratings section 4 5 5-12, 16-18 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated's website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. (c) 2017 Maxim Integrated Products, Inc. 27