General Description

The MAX98388/MAX98389 is a small, cost-effective mono digital input amplifier with integrated IV feedback. The device operates over a wide supply voltage range from 2.3V to 10V. With this supply range, both versions support single-cell, two-cell, and externally regulated/boosted portable applications. MAX98388 is optimized for up to 5.5V applications (single-cell), while MAX98389 is optimized for 5V to 10V 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 0.4mm pitch 16-bump WLP package and is specified over the extended -40°C to +85°C temperature range.

Benefits and Features

• Wide Amplifier Supply Range (2.3V to 10V)

• Supports Both Single-Cell and Two-Cell Cases

• High-Performance Class-D Amplifier

• Up to 111dB Dynamic Range (A-Weighted)

• 10μVRMS Output Noise (Single-Cell Mode)

• 14.5μVRMS Output Noise (Two-Cell Mode)

• High Output Power (THD+N ≤ 1)

• 1.32W Output Power into 4Ω (VPVDD = 3.7V)

• 2.4W Output Power into 4Ω (VPVDD = 5V)

• 5.15W Output Power into 4Ω (VPVDD = 7.4V)

• 9.1W Output Power into 4Ω (VPVDD = 10V)

• High Amplifier Efficiency (Playback Only Power)

• 76 Efficiency at 0.1W into 4Ω (VPVDD = 5V)

• 85.5 Efficiency at 1W into 4Ω (VPVDD = 5V)

• 90 Efficiency at 1W into 8Ω (VPVDD = 5V)

• Peak THD+N Better than -83dB at 1kHz

• Low Total Quiescent Power

• 9.3mW (VPVDD = 3.7V, IV Feedback Disabled)

• 13.9mW (VPVDD = 3.7V, IV Feedback Enabled)

• 16.1mW (VPVDD = 5V, IV Feedback Enabled)

• 22.5mW (VPVDD = 7.4V, IV Feedback Enabled)

• Low < 5μW Software Shutdown Power

• 1ms Turn-On Time (fS = 48kHz, Ramp Disabled)

• Five Sample Playback Delay (fS < 50kHz, fIN = 1kHz)

• No External Reference Clock Required

• Playback Sample Rates from 8kHz to 96kHz

• Trimmed Class-D Switching Frequency for EMI Planning

• Extensive Click-and-Pop Reduction Circuitry

• Programmable ALC for Brownout Protection

• Robust Short-Circuit and Thermal Protection

• Available in Space-Saving Package:

• 2.93mm2, 16-pin WLP (0.4mm Pitch)

Applications

• AR/VR Wearables

• LRA Haptic Drive

• Smart Watches and IoT Devices

• Gaming Devices

• Notebooks and Tablets