By Maxim Integrated 270
Maxim's MAX98390 is a high-efficiency mono Class-D DSM smart amplifier that features an integrated boost converter, integrated DSM, 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 allows 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.