The MAX9791 combines a stereo 2W Class D power amplifier, a stereo 180mW DirectDrive® headphone amplifier, and a 120mA low-dropout (LDO) linear regulator in a single device. The MAX9792 combines a mono 3W Class D power amplifier, a stereo 180mW DirectDrive headphone amplifier, and a 120mA LDO linear regulator in a single device. The MAX9791/MAX9792 feature Maxim’s DirectDrive headphone amplifier architecture that produces a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, board space, and component height. High 107dB DC PSRR and low 0.006% THD+N ensure clean, low-distortion amplification of the audio signal. The ground sense feature senses and corrects for the voltage difference between the output jack ground and device signal ground. This feature minimizes headphone amplifier crosstalk by sensing the impedance in the ground return trace and correcting for it at the output jack. This feature also minimizes ground-loop noise when the output socket is used as a line out connection to other grounded equipment (for example, a PC connected to a home hi-fi system). The MAX9791/MAX9792 feature low RF susceptibility, allowing the amplifiers to successfully operate in close proximity to wireless applications. The MAX9791/MAX9792 Class D amplifiers feature Maxim’s spread-spectrum modulation and active emissions limiting circuitry. Industry-leading click-and-pop suppression eliminates audio noise and pops.
The MAX9791 combines a stereo 2 W Class D speaker amplifier with a stereo 180 mW DirectDrive® headphone amplifier and a 120 mA low‑dropout linear regulator. The MAX9792 provides a mono 3 W Class D speaker amplifier with the same headphone and LDO features. Both devices include spread‑spectrum modulation, click‑and‑pop suppression, wake‑on‑beep control, and independent enable pins for the speaker, headphone, and LDO sections.
Designed for Windows Vista‑compatible portable audio platforms, the amplifiers operate from a 2.7 V to 5.5 V supply, deliver up to 83 % efficiency, and feature high DC power‑supply rejection (107 dB) and ultra‑low total harmonic distortion (0.006 %). Thermal‑overload and short‑circuit protection ensure reliable operation in harsh environments.
| Speaker Output Power (MAX9791) | 2 W stereo |
|---|---|
| Speaker Output Power (MAX9792) | 3 W mono |
| THD+N | 0.006 % |
| Power‑Supply Rejection Ratio (PSRR) | 107 dB |
| Integrated LDO Current | 120 mA |
The amplifiers achieve a very low THD+N of 0.006 %.
Yes, a qualified beep on the BEEP input wakes up the speaker and headphone amplifiers.
They provide thermal‑overload and output short‑circuit protection.