EVALUATION KIT AVAILABLE Click here for production status of specific part numbers. MAX98357A/ Tiny, Low-Cost, PCM Class D Amplifier with MAX98357B Class AB Performance General Description Features The MAX98357A/MAX98357B is an easy-to-use, low-cost, Single-Supply Operation (2.5V to 5.5V) digital pulse-code modulation (PCM) input Class D ampli- 3.2W Output Power into 4 at 5V fier that provides industry-leading Class AB audio perfor- 2.4mA Quiescent Current mance with Class D efficiency. The digital audio interface 92% Efficiency (R = 8, P = 1W) L OUT automatically recognizes up to 35 different PCM and TDM 2 22.8V Output Noise (A = 15dB) clocking schemes which eliminates the need for I C pro- RMS V gramming. Operation is further simplified by eliminating Low 0.013% THD+N at 1kHz the need for an external MCLK signal that is typically used No MCLK Required for PCM communication. Simply supply power, LRCLK, Sample Rates of 8kHz to 96kHz BCLK, and digital audio to generate audio Furthermore, Supports Left, Right, or (Left/2 + Right/2) Output a novel pinout allows customers to use the cost-effective WLP package with no need for expensive vias (refer Sophisticated Edge Rate Control Enables to Application Note 6643: Optimize Cost, Size, and Filterless Class D Outputs Performance with MAX98357 WLP for more information). 77dB PSRR at 1kHz The digital audio interface is highly flexible with the Low RF Susceptibility Rejects TDMA 2 MAX98357A supporting I S data and the MAX98357B Noise from GSM Radios supporting left-justified data. Both ICs support 8 channel Extensive Click-and-Pop Reduction Circuitry time division multiplexed (TDM) data. The digital audio Robust Short-Circuit and Thermal Protection interface accepts specified sample rates between 8kHz and 96kHz for all supported data formats. The ICs can Available in Space-Saving Packages: be configured to produce a left channel, right channel, or 1.345mm x 1.435mm WLP (0.4mm Pitch) (left/2 + right/2) output from the stereo input data. The ICs and 3mm x 3mm TQFN 2 operate using 16/24/32-bit data for I S and left-justified Solution Size with Single Bypass Capacitor is modes as well as 16-bit or 32-bit data using TDM mode. 2 4.32mm The ICs eliminate the need for the external MCLK signal that is typically used for PCM communication. This reduc- Applications es EMI and possible board coupling issues in addition to Single Li-ion Cell/5V Devices reducing the size and pin count of the ICs. Smart Speakers The ICs also feature a very high wideband jitter toler- Notebook Computers ance (12ns typ) on BCLK and LRCLK to provide robust IoT Devices operation. Gaming Devices (Audio and Haptics) Active emissions-limiting, edge-rate limiting, and over- Smartphones shoot control circuitry greatly reduce EMI. A filterless Tablets spread-spectrum modulation scheme eliminates the need Cameras for output filtering found in traditional Class D devices and reduces the component count of the solution. Simplified Block Diagram The ICs are 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 are specified over the -40C to +85C tem- SHUTDOWN perature range. AND GAIN MAX98357A CHANNEL CONTROL MAX98357B SELECT Ordering Information appears at end of data sheet. DIGITAL CLASS D PCM AUDIO DAC OUTPUT Functional Diagram appears at end of data sheet. INPUT STAGE INTERFACE 19-6779 Rev 13 7/19MAX98357A/ Tiny, Low-Cost, PCM Class D Amplifier with MAX98357B Class AB Performance TABLE OF CONTENTS General Description ............................................................................ 1 Features ..................................................................................... 1 Applications .................................................................................. 1 Simplified Block Diagram........................................................................ 1 Absolute Maximum Ratings ...................................................................... 4 Package Thermal Characteristics ................................................................. 4 Electrical Characteristics ........................................................................ 4 Typical Operating Characteristics ................................................................. 9 Pin Configurations ............................................................................ 15 Pin Description ............................................................................... 15 Detailed Description........................................................................... 16 Digital Audio Interface Modes 16 MCLK Elimination 16 BCLK Jitter Tolerance . 16 BCLK Polarity 16 LRCLK Polarity 16 Standby Mode . 16 DAC Digital Filters . 17 SD MODE and Shutdown Operation . 17 Startup . 18 2 I S and Left Justified Mode . 19 TDM Mode 19 Class D Speaker Amplifier 28 Ultra-Low EMI Filterless Output Stage 28 Speaker Current Limit . 28 Gain Selection . 28 Click-and-Pop Suppression . 28 Applications Information........................................................................ 29 Filterless Class D Operation . 33 Power-Supply Input 33 Layout and Grounding 33 Functional Diagram ........................................................................... 33 WLP Applications Information 34 Ordering Information .......................................................................... 34 Package Information .......................................................................... 35 Revision History .............................................................................. 38 Maxim Integrated 2 www.maximintegrated.com