MAX9875 is a high-efficiency Class D audio power amplifier with a built-in stereo AB-class capacitor-less DirectDrive headphone amplifier. This amplifier uses Maxim's third-generation filterless Class D amplifier technology with active emissions limiting technology to provide Class AB performance with Class D efficiency. The MAX9875 can provide up to 725mW of power from a 3.7V supply to an 8Ω load with an efficiency of 87%, extending battery life. The filterless modulation scheme combined with active emissions limiting circuitry and spread-spectrum modulation greatly reduces EMI while eliminating the need for output filtering used in traditional Class D devices. The stereo AB-class headphone amplifier in the MAX9875 uses Maxim's DirectDrive architecture, which produces a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, space and component height. The device uses a user-defined input architecture, three preamplifier gain settings, an input mixer, volume control, comprehensive click-and-pop suppression and I2C control. The MAX9875 is available in a thermally efficient, space-saving 20-bump WLP package.
The MAX9875 combines a high‑efficiency Class‑D speaker amplifier with a stereo Class‑AB DirectDrive® headphone amplifier. It delivers up to 725 mW speaker output and 53 mW headphone output while maintaining low emissions and 87 % efficiency. The device offers user‑defined input architecture, three pre‑amplifier gain settings, click‑and‑pop suppression, and I²C control in a compact 20‑bump WLP package.
Typical applications include cell phones and portable multimedia players. The document provides absolute maximum ratings, detailed electrical characteristics, typical operating curves, a reference application circuit, and full package dimensions for designers.
| Speaker Output Power | 725 mW into 8 Ω |
|---|---|
| Headphone Output Power | 53 mW into 16 Ω |
| Speaker THD+N | 0.05 % at 1 kHz |
| Headphone THD+N | 0.016 % at 1 kHz |
| Efficiency | 87 % (at 750 mW output) |
| Current Limit | 1.5 A |
| Package | 20‑bump WLP, 5 × 4 mm |
The MAX9875 can deliver up to 725 mW into an 8 Ω load.
The device achieves 87 % efficiency.
It is available in a 20‑bump WLP package measuring 5 × 4 mm.