11.7W Digital Input Class DG Amplifier with I/V Sense and Ultra-Low Quiescent Power

The MAX98395 is a 11.7W high-efficiency, mono Class-DG speaker amplifier with industry leading quiescent power and a wide supply range that can even support single cell Li+ batteries or an external boost. MAX98395 also features current and voltage sense (I/V sense) and dynamic headroom tracking (DHT). Precision output current and voltage monitoring (I/V sense) enables speaker protection algorithms to be run by a host device. Spread spectrum modulation (SSM) and edge rate control minimize EMI and eliminate the need for the output filtering found in traditional Class-D devices.

To achieve industry-leading quiescent power, the Class-DG amplifier employs two supply rails, VBAT and PVDD, to supply the speaker amplifier. Additionally, as the power-supply voltage varies due to sudden transients and declining battery life, DHT automatically optimizes the headroom available to the Class-DG amplifier to maintain consistent distortion and listening levels. The DHT block provides both a dynamic range compressor (DRC) and a limiter that can operate as either a signal distortion limiter (SDL) or standard signal level limiter (SLL).

The device provides a PCM interface for audio data and a standard I2C interface for control data communication. The PCM interface supports audio playback using I2S, left-justified, and TDM audio data formats. In TDM mode, the device can support up to 16 channels of audio data. A unique clocking structure eliminates the need for an external master clock for PCM communication, which reduces pin count and simplifies board layout.

Thermal-foldback protection ensures robust behavior when the thermal limits of the device are reached. When enabled, it automatically reduces the output power when the temperature exceeds a user-specified threshold. This allows for uninterrupted music playback even at high ambient temperatures. Traditional thermal protection is also available in addition to robust over-current protection.

The device is available in a 0.4mm pitch, 28-bump wafer-level package (WLP). The device operates over the extended -40°C to +85°C temperature range.

Applications

* Mobile Speakers * Notebook Computers * Smart IoT * Smart Speakers * Soundbars * Tablets

* Wide Input Supply Range (3.0V to 14V)

* Class-DG Operation Enables Industry Leading Quiescent Power

* 16mW at VPVDD = 3.8V

* 15mW at VPVDD = 12V

* Ultra-Low Noise Floor

* 11µVRMS Output Noise

* 116dB Dynamic Range

* Low Distortion

* -83dB THD+N at 2W into 8Ω, f = 1kHz and 3kHz

* -77dB THD+N at 2W into 8Ω, f = 6kHz

* Output Power at 1% THD+N:

* 7.7W into 8Ω, VPVDD = 12V

* 11.7W into 4Ω, VPVDD = 12V

* Speaker Amplifier Efficiency:

* 88% at 5W into 8Ω, VPVDD = 12V

* Class-D EMI Reduction Enables Filterless Operation

* Spread-Spectrum Modulation

* Switching Edge Rate Control

* Integrated Speaker Current and Voltage Sense Requires no External Components

* I2S/16-Channel TDM and I2C Digital Interfaces

* Playback and IV Paths Support Sample Rates up to 96kHz

* Dynamic Headroom Tracking (DHT) Maintains a Consistent Listening Experience

* Extensive Click-and-Pop Suppression

* 28-Bump WLP (1.62mm x 2.88mm x 0.5mm, 0.4mm Pitch)