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Tiny, Low-Cost, PCM Class D Amplifier with Class AB Performance

Supports I2S and 8-Channel TDM Data

Product Details

For improved performance, functionality, and even lower power consumption Maxim Integrated recommends the MAX98360.

The MAX98357A/MAX98357B is an easy-to-use, low-cost, digital pulse-code modulation (PCM) input Class D amplifier that provides industry-leading Class AB audio performance with Class D efficiency. The digital audio interface automatically recognizes up to 35 different PCM and TDM clocking schemes which eliminates the need for I2C programming. Operation is further simplified by eliminating the need for an external MCLK signal that is typically used for PCM communication. Simply supply power, LRCLK, BCLK, and digital audio to generate audio! Furthermore, a novel pinout allows customers to use the cost-effective WLP package with no need for expensive vias (refer to Application Note 6643: Optimize Cost, Size, and Performance with MAX98357 WLP for more information).

The digital audio interface is highly flexible with the MAX98357A supporting I2S data and the MAX98357B supporting left-justified data. Both ICs support 8 channel time division multiplexed (TDM) data. The digital audio interface accepts specified sample rates between 8kHz and 96kHz for all supported data formats. The ICs can be configured to produce a left channel, right channel, or (left/2 + right/2) output from the stereo input data. The ICs operate using 16/24/32-bit data for I2S and left-justified modes as well as 16-bit or 32-bit data using TDM mode. The ICs eliminate the need for the external MCLK signal that is typically used for PCM communication. This reduces EMI and possible board coupling issues in addition to reducing the size and pin count of the ICs.

The ICs also feature a very high wideband jitter tolerance (12ns typ) on BCLK and LRCLK to provide robust operation.

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.

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 -40°C to +85°C temperature range.

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Key Features

  • Single-Supply Operation (2.5V to 5.5V)
  • 3.2W Output Power into 4Ω at 5V
  • 2.4mA Quiescent Current
  • 92% Efficiency (RL = 8Ω, POUT = 1W)
  • 22.8µVRMS Output Noise (AV = 15dB)
  • Low 0.013% THD+N at 1kHz
  • No MCLK Required
  • Sample Rates of 8kHz to 96kHz
  • Supports Left, Right, or (Left/2 + Right/2) Output
  • Sophisticated Edge Rate Control Enables Filterless Class D Outputs
  • 77dB PSRR at 1kHz
  • Low RF Susceptibility Rejects TDMA Noise from GSM Radios
  • Extensive Click-and-Pop Reduction Circuitry
  • Robust Short-Circuit and Thermal Protection
  • Available in Space-Saving Packages: 1.345mm x 1.435mm WLP (0.4mm Pitch) and 3mm x 3mm TQFN
  • Solution Size with Single Bypass Capacitor is4.32mm2

Applications/Uses

  • Cameras
  • Gaming Devices (Audio and Haptics)
  • IoT Devices
  • Notebook Computers
  • Single Li-ion Cell/5V Devices
  • Smart Speakers
  • Smartphones
  • Tablets
Parametric specs for Speaker Amplifiers
# Channels 1
Class D
Spkr. Amp. VCC (V) (min) 2.5
Spkr. Amp. VCC (V) (max) 5.5
Spkr. Amp. ICC (mA) (typ) 2.5
POUT into 4Ω @ 1% THD+N (W) (min) 2.5
POUT into 4Ω @ 10% THD+N (W) (min) 3.2
POUT into 8Ω @ 1% THD+N (W) (min) 1.4
POUT into 8Ω @ 10% THD+N (W) (min) 1.8
Spkr. Amp. Half Pwr. THD+N (%) 0.013
SNR (dB) (A- Weighted) 105
PSRR (dB) (min) 77
Package/Pins TQFN/16
WLP/9
Budgetary
Price (See Notes)
$0.91 @1k
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Simplified Block Diagram

PCM Class D Amplifier with Class AB performance Functional Diagram MAX98357A/B MAX98357A, MAX98357B: Functional Diagram Zoom icon

Technical Docs

Design & Development

Click any title below to view the detail page where available.

Description

The MAX98357 development board (DEV board) is a fully assembled and tested PCB that evaluates the MAX98357 I2S digital input Class D power amplifier. The DEV board operates from a single 2.5V to 5.5V DC power supply and is capable of delivering 3.2W into a 4Ω load. The device outputs can be connected directly to a speaker load for filterless applications. However, a filter can be added to ease evaluation. The MAX98357A accepts standard I2S data and the MAX98357B accepts left-justified digital audio data. Both versions also support 8-channel TDM audio data.

The MAX98357 evaluation system (EV system) includes the MAX98357 DEV board and Maxim Integrated’s audio interface board (MAXAUDINT001# board).

The MAXAUDINT001# board provides an easy-to-use USB audio-to-I2S converter. This allows for any computer to become a digital audio source, which can be used to evaluate the devices. The MAXAUDINT001# board can also be used to power the MAX98357. This allows for a complete evaluation from a single USB connection.

View Details

Features

  • 2.5V to 5.5V Single-Supply Operation
  • Only a Single External Component (VDD Capacitor) Required in Many Applications
  • I2S, Left-Justified, or TDM Input
  • Five Selectable Gains (3dB, 6dB, 9dB, 12dB, and 15dB)
  • Audio Channel Select (Left, Right, and Mono Mix)
  • Filterless Operation
  • Optional Class D Output Filters for Ease of Evaluation
  • Proven PCB Layout
  • Fully Assembled and Tested

Description

The MAX98357 development board (DEV board) is a fully assembled and tested PCB that evaluates the MAX98357 I2S digital input Class D power amplifier. The DEV board operates from a single 2.5V to 5.5V DC power supply and is capable of delivering 3.2W into a 4Ω load. The device outputs can be connected directly to a speaker load for filterless applications. However, a filter can be added to ease evaluation. The MAX98357A accepts standard I2S data and the MAX98357B accepts left-justified digital audio data. Both versions also support 8-channel TDM audio data.

The MAX98357 evaluation system (EV system) includes the MAX98357 DEV board and Maxim Integrated’s audio interface board (MAXAUDINT001# board).

The MAXAUDINT001# board provides an easy-to-use USB audio-to-I2S converter. This allows for any computer to become a digital audio source, which can be used to evaluate the devices. The MAXAUDINT001# board can also be used to power the MAX98357. This allows for a complete evaluation from a single USB connection.

View Details

Features

  • 2.5V to 5.5V Single-Supply Operation
  • Only a Single External Component (VDD Capacitor) Required in Many Applications
  • I2S, Left-Justified, or TDM Input
  • Five Selectable Gains (3dB, 6dB, 9dB, 12dB, and 15dB)
  • Audio Channel Select (Left, Right, and Mono Mix)
  • Filterless Operation
  • Optional Class D Output Filters for Ease of Evaluation
  • Proven PCB Layout
  • Fully Assembled and Tested

Description

The MAX98357 development board (DEV board) is a fully assembled and tested PCB that evaluates the MAX98357 I2S digital input Class D power amplifier. The DEV board operates from a single 2.5V to 5.5V DC power supply and is capable of delivering 3.2W into a 4Ω load. The device outputs can be connected directly to a speaker load for filterless applications. However, a filter can be added to ease evaluation. The MAX98357A accepts standard I2S data and the MAX98357B accepts left-justified digital audio data. Both versions also support 8-channel TDM audio data.

The MAX98357 evaluation system (EV system) includes the MAX98357 DEV board and Maxim Integrated’s audio interface board (MAXAUDINT001#).

The MAXAUDINT001# board provides an easy-to-use USB audio-to-I2S converter. This allows for any computer to become a digital audio source, which can be used to evaluate the devices. The MAXAUDINT001# board can also be used to power the MAX98357. This allows for a complete evaluation from a single USB connection.

View Details

Features

  • 2.5V to 5.5V Single-Supply Operation
  • Only a Single External Component (VDD Capacitor) Required in Many Applications
  • I2S, Left-Justified, or TDM Input
  • Five Selectable Gains (3db, 6dB, 9dB, 12dB, and 15dB)
  • Audio Channel Select (Left, Right, and Mono Mix)
  • Filterless Operation
  • Optional Class D Output Filters for Ease of Evaluation
  • Proven PCB Layout
  • Fully Assembled and Tested

Description

The MAX98357 development board (DEV board) is a fully assembled and tested PCB that evaluates the MAX98357 I2S digital input Class D power amplifier. The DEV board operates from a single 2.5V to 5.5V DC power supply and is capable of delivering 3.2W into a 4Ω load. The device outputs can be connected directly to a speaker load for filterless applications. However, a filter can be added to ease evaluation. The MAX98357A accepts standard I2S data and the MAX98357B accepts left-justified digital audio data. Both versions also support 8-channel TDM audio data.

The MAX98357 evaluation system (EV system) includes the MAX98357 DEV board and Maxim Integrated’s audio interface board (MAXAUDINT001#).

The MAXAUDINT001# board provides an easy-to-use USB audio-to-I2S converter. This allows for any computer to become a digital audio source, which can be used to evaluate the devices. The MAXAUDINT001# board can also be used to power the MAX98357. This allows for a complete evaluation from a single USB connection.

View Details

Features

  • 2.5V to 5.5V Single-Supply Operation
  • Only a Single External Component (VDD Capacitor) Required in Many Applications
  • I2S, Left-Justified, or TDM Input
  • Five Selectable Gains (3db, 6dB, 9dB, 12dB, and 15dB)
  • Audio Channel Select (Left, Right, and Mono Mix)
  • Filterless Operation
  • Optional Class D Output Filters for Ease of Evaluation
  • Proven PCB Layout
  • Fully Assembled and Tested

Description

When used as a component in the MAX98357/MAX98358 dev kit or evsys NO driver is required.

The Maxim Audio Interface 1 (AUDINT1) board provides both an I2C and I2S interface to facilitate the evaluation of compatible Maxim Development (DEV) boards. Maxim DEV boards that are evaluated with the AUDINT1 interface board can require custom GUI software, which is available as a download from Maxim’s evkit-software web page.

The AUDINT1 board and a compatible DEV board are ordered together as an evaluation system (EV system). Ordering information for EV systems is located in the EV system data sheet.

Refer to the appropriate EV system data sheet for quick start and detailed operating instructions.

The AUDINT1 board is provided as part of selected Maxim evaluation systems (EV system) to evaluate Maxim parts only. The use of the AUDINT1 board as a development target is not supported. Refer to the MAXQ2000 evaluation kit data sheet for this purpose.

View Details

Features

  • USB Powered (+5V)
  • USB-to-I2C (USB CONTROL)
  • USB-to-I2S (USB AUDIO)
  • On-Board Master Clock Sources
  • On-Board LDOs (+1.2V, +1.8V, +3.3V)
  • Compatible with Standard FTDI VCP Drivers
  • Fully Assembled and Tested

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Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal

Parameters

Parametric specs for Speaker Amplifiers
# Channels 1
Class D
Spkr. Amp. VCC (V) (min) 2.5
Spkr. Amp. VCC (V) (max) 5.5
Spkr. Amp. ICC (mA) (typ) 2.5
POUT into 4Ω @ 1% THD+N (W) (min) 2.5
POUT into 4Ω @ 10% THD+N (W) (min) 3.2
POUT into 8Ω @ 1% THD+N (W) (min) 1.4
POUT into 8Ω @ 10% THD+N (W) (min) 1.8
Spkr. Amp. Half Pwr. THD+N (%) 0.013
SNR (dB) (A- Weighted) 105
PSRR (dB) (min) 77
Package/Pins TQFN/16
WLP/9
Budgetary
Price (See Notes)
$0.91 @1k

Key Features

  • Single-Supply Operation (2.5V to 5.5V)
  • 3.2W Output Power into 4Ω at 5V
  • 2.4mA Quiescent Current
  • 92% Efficiency (RL = 8Ω, POUT = 1W)
  • 22.8µVRMS Output Noise (AV = 15dB)
  • Low 0.013% THD+N at 1kHz
  • No MCLK Required
  • Sample Rates of 8kHz to 96kHz
  • Supports Left, Right, or (Left/2 + Right/2) Output
  • Sophisticated Edge Rate Control Enables Filterless Class D Outputs
  • 77dB PSRR at 1kHz
  • Low RF Susceptibility Rejects TDMA Noise from GSM Radios
  • Extensive Click-and-Pop Reduction Circuitry
  • Robust Short-Circuit and Thermal Protection
  • Available in Space-Saving Packages: 1.345mm x 1.435mm WLP (0.4mm Pitch) and 3mm x 3mm TQFN
  • Solution Size with Single Bypass Capacitor is4.32mm2

Applications/Uses

  • Cameras
  • Gaming Devices (Audio and Haptics)
  • IoT Devices
  • Notebook Computers
  • Single Li-ion Cell/5V Devices
  • Smart Speakers
  • Smartphones
  • Tablets

Description

For improved performance, functionality, and even lower power consumption Maxim Integrated recommends the MAX98360.

The MAX98357A/MAX98357B is an easy-to-use, low-cost, digital pulse-code modulation (PCM) input Class D amplifier that provides industry-leading Class AB audio performance with Class D efficiency. The digital audio interface automatically recognizes up to 35 different PCM and TDM clocking schemes which eliminates the need for I2C programming. Operation is further simplified by eliminating the need for an external MCLK signal that is typically used for PCM communication. Simply supply power, LRCLK, BCLK, and digital audio to generate audio! Furthermore, a novel pinout allows customers to use the cost-effective WLP package with no need for expensive vias (refer to Application Note 6643: Optimize Cost, Size, and Performance with MAX98357 WLP for more information).

The digital audio interface is highly flexible with the MAX98357A supporting I2S data and the MAX98357B supporting left-justified data. Both ICs support 8 channel time division multiplexed (TDM) data. The digital audio interface accepts specified sample rates between 8kHz and 96kHz for all supported data formats. The ICs can be configured to produce a left channel, right channel, or (left/2 + right/2) output from the stereo input data. The ICs operate using 16/24/32-bit data for I2S and left-justified modes as well as 16-bit or 32-bit data using TDM mode. The ICs eliminate the need for the external MCLK signal that is typically used for PCM communication. This reduces EMI and possible board coupling issues in addition to reducing the size and pin count of the ICs.

The ICs also feature a very high wideband jitter tolerance (12ns typ) on BCLK and LRCLK to provide robust operation.

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.

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 -40°C to +85°C temperature range.

Mobile App

Simplified Block Diagram

PCM Class D Amplifier with Class AB performance Functional Diagram MAX98357A/B MAX98357A, MAX98357B: Functional Diagram Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal