MAX98390 Amplifiers with Integrated Dynamic Speaker Management

Analog Devices' MAX98390 is a high-efficiency mono Class-D integrated DSM smart amplifier that features an integrated boost converter and FET scaling for higher efficiency at low output power.

The maximum boost converter output voltage is programmable from 6.5 V to 10 V in 0.125 V increments from a battery voltage as low as 2.65 V. The boost converter supports bypass mode for lower quiescent current and improved mid-power efficiency as well as envelope tracking which automatically adjusts the output voltage for maximum efficiency. The boosted supply efficiently delivers up to 6.2 W at 10% THD+N into a 4 Ω load.

Integrated IV sense and DSM allow louder, fuller audio while protecting the speaker against damage and improving sound quality.

The PCM interface supports I²S, left-justified, and 16-channel TDM formats as a slave or master device with I²C control. Either BCLK or MCLK can be used as the internal clock source providing system-level flexibility. Thermal and other status data can also be read from the I²C interface.

Patented active emissions limiting edge rate and overshoot control circuitry minimizes EMI and eliminates the need for output filtering found in traditional Class-D devices.

A flexible brownout-detection engine (BDE) can be programmed to initiate various current limiting, signal limiting, and clip functions to prevent dips in battery voltage. Threshold, hysteresis, and attack-and-release rates are programmable.

The MAX98390C/D evaluation system (EV system) evaluates the MAX98390C or the MAX98390D boosted Class D audio amplifier with integrated dynamic speaker management (DSM) IC. DSM senses the voltage and current at the load and uses patented Analog Devices algorithms to unlock the full potential of the speaker. The EV system comprises the MAX98390C or the MAX98390D Development Board (DEV board), Analog Devices’ Audio Interface Board III (AUDINT3), 5 V power supply, reference micro- speaker, USB cable, DSM Sound Studio software, and MAX98390 evaluation software.

It is recommended that the DEV board be evaluated with the AUDINT3 board as an EV system. MAX98390C/D supports standard I²S, left-justified, and TDM digital audio interfaces, as well as I²C for control.