The MAX9789/MAX9790 combine a stereo, 2W Class AB speaker power amplifier with a stereo 100mW DirectDrive® headphone amplifier in a single device.
The MAX9789/MAX9790 devices combine a 2 W Class‑AB stereo speaker amplifier with a 100 mW DirectDrive® headphone amplifier in a single 32‑pin thin QFN package. They are designed for Microsoft Windows Vista‑compliant systems and operate from a single 4.5 V to 5.5 V supply. Integrated features include a low‑dropout regulator, click‑and‑pop suppression, and independent shutdown control for speaker and headphone sections.
The datasheet provides absolute maximum ratings, detailed electrical characteristics, typical operating curves, pin configurations, and package information. Key performance figures such as +90 dB PSRR, 0.002 % THD+N, and up to 2 W speaker output into 4 Ω are documented, along with LDO output voltage settings and power‑dissipation data.
| Speaker Output Power | 2 W into 4 Ω |
|---|---|
| Power‑Supply Rejection Ratio (PSRR) | +90 dB |
| Integrated LDO Output Voltage | 4.75 V (adjustable 1.21 V–4.75 V) |
It can deliver up to 2 W into a 4 Ω load.