MAX98415A

The MAX98415A/MAX98425A is a high-efficiency, stereo Class-D speaker amplifier with industry-leading quiescent power featuring Envelope Tracking control, Brownout Prevention Engine (BPE), Dynamic Headroom Tracking (DHT), and RMS Limiter. MAX98415A includes precision output current monitoring (I_SENSE) and speaker feedback voltage (V_FEEDBACK) to enable speaker protection algorithms that can be run by a host device. Both devices support sample rates up to 192kHz and a higher passband (for f_S> 50kHz) to enable high-resolution audio and ultrasound use cases. A separate bypass path is available for inputs, such as an ultrasound signal, so that it is not attenuated by audio processing. SSM and edge rate control minimize EMI and eliminate the need for output filtering found in traditional Class-D devices.The Envelope Tracking algorithm on the device monitors the incoming audio signal and generates a PWM signal to control an external DC-DC converter to keep the amplifier supply close to the peak output audio signal, thereby improving system efficiency, idle quiescent power consumption, and thermal efficiency.For battery-powered applications, the BPE helps avoid a system brownout by reducing the device’s current consumption. This is achieved by either attenuating or limiting the amplifier output when the device supply drops below a set of programmable thresholds. In addition, as the amplifier supply varies due to sudden transients and declining battery life, DHT automatically optimizes the headroom available to the amplifier to maintain a consistent distortion level.The device provides a PCM interface for audio data and a standard I²C interface for control data communication.Thermal foldback, when enabled, 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 overcurrent protection.