Class-D stereo audio amplifier saves battery power and has superior sound quality

Diodes Incorporated has released the PAM8965 Class-D stereo audio power amplifier with an integrated synchronous boost converter. This high-efficiency device is aimed at employment in AI-enabled speaker systems and portable musical instruments, where elevated output power, extended battery life, and compact construction are all essential demands.

Running off a 2.8V to 8.5V supply, the device can drive 12W into 4Ohm speakers through each of its two channels, with 92% efficiency. By including a synchronous boost converter, with PFM operation at light loads, this device is not only able to produce augmented performance and efficiency levels, but it also decreases board space usage and lowers the overall BOM costs.

The product’s SSM results in more effective EMI suppression across a wide range of frequencies. This enables the use of inexpensive ferrite bead filters rather than more costly and bulky LC filters. The boost converter’s ultrasonic PFM operation minimises the impact of audible noise emanating from other components on the PCB. Also, Class-D and boost SSM switching is synchronised to avoid beats.

The device's non-clipping power limit assures that speakers continue to produce superior audio fidelity with no risk of damage. The thermal foldback function decreases output power if the amplifier device begins to overheat. Undervoltage, overvoltage, and short-circuit protection, as well as thermal shutdown, are also incorporated. A low quiescent current of only 10mA serves to further conserve battery charge.