MAX98388/MAX98389 Mono Digital Input Amplifiers

ADI's MAX98388 and MAX98389 are small, cost-effective mono digital input amplifiers with integrated IV feedback. The device operates over a wide supply voltage range from 2.3 V to 10 V. With this supply range, both versions support one-cell, two-cell, and externally regulated/boosted portable applications. MAX98388 is optimized for up to 5.5 V applications (one-cell), while MAX98389 is optimized for 5 V to 10 V cases (two-cell).

The Class-D playback amplifier pairs Class-AB level audio performance with the efficiency needed to extend battery life in portable applications. Active emissions-limiting (AEL) and edge-rate limiting circuitry combined with a spread-spectrum modulation (SSM) scheme reduces EMI and eliminates the need for the output filtering required for traditional Class-D amplifiers.

The device provides a precision output current sense channel and an output voltage feedback channel. The data collected by these channels can be transmitted on the audio data output and enables algorithms such as audio enhancement, bass boosting, speaker protection, and haptic functions to be run on the host audio DSP. The device includes a programmable threshold playback channel ALC that provides brownout protection for batteries in portable systems, and robust thermal and overcurrent protection to prevent device damage.

The device provides a PCM interface for audio playback and IV feedback data and pairs this with a standard I²C interface for device control and status readback. The PCM interface supports common audio data formats such as I²S, left justified, and TDM timing. A unique clocking structure eliminates the need for an external high-frequency reference clock. In addition to reducing device size and pin count, eliminating this clock saves interface power while reducing the risk of EMI from high-speed switching and potential board coupling issues.

The package connections are designed to only require edge routing, allowing the use of the cost-effective wafer-level package (WLP) with no requirement for expensive bump vias. The device is available in a 0.4 mm pitch 16-bump WLP package and is specified over the extended -40°C to +85°C temperature range.

The MAX98388 and MAX98389 evaluation (EV) systems are fully assembled and tested systems that evaluate the MAX98388 or MAX98389 Class-D audio amplifier. The EV system consists of either the MAX98388 or MAX98389 development board (DEV board), Analog Devices Audio Interface Board III (AUDINT3), and a USB cable.