MAX98396

The MAX98396 is a high-efficiency, mono Class-DG speaker amplifier with industry-leading quiescent power featuring I/V sense, brownout-prevention engine (BPE), and dynamic-headroom tracking (DHT). The IC enables ultrasound applications by providing support for sample rates up to 192kHz, a higher passband (for f_s> 50kHz), and a bypass path for the ultrasound signals through the amplifier so it is not attenuated by the audio processing. Precision output current and voltage monitoring (I/V sense) enables the host device to run speaker protection algorithms. 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 (3V to 5.5V) and PVDD (3V to 20V) to supply the speaker amplifier. The Class-DG amplifier switches between the two supply rails depending on the input signal level and/or the supply headroom. The brownout-prevention engine in the device allows it to reduce its contribution to the overall system power consumption by either attenuating or limiting the amplifier output when the device supply drops below a set of programmable thresholds. 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 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. A unique clocking structure eliminates the need for an external master clock for PCM communication, which reduces pin count and simplifies board layout. Enabling thermal foldback 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.

The device is available in a 0.4mm pitch, 35-bump wafer-level package (WLP). The device operates over the extended -40°C to +85°C temperature range.