Diodes unveils high-efficiency Class-D stereo audio amplifier

This high-efficiency device is targeted for use in AI-enabled speaker systems and portable musical instruments - where elevated output power, extended battery life, and compact construction are all key requirements.

Running off a 2.8V to 8.5V supply, the PAM8965 has the capability to drive 12W into 4Ω speakers via each of its two channels, with 92% efficiency. By incorporating a synchronous boost converter, with pulse frequency modulation (PFM) operation at light loads, this device is not only able to deliver augmented performance and efficiency levels, but it also reduces board space usage and lowers the overall bill-of-materials (BOM) costs.

The product’s spread spectrum modulation (SSM) results in more effective electromagnetic interference (EMI) suppression across a broad range of frequencies. This allows the use of inexpensive ferrite bead filters, rather than more costly and bulky LC filters. The boost converter’s ultrasonic PFM operation reduces the impact of audible noise emanating from other components situated on the PCB. In addition, Class-D and boost SSM switching is synchronized to avoid beats.

The PAM8965's non-clipping power limit ensures that speakers continue to provide superior audio fidelity without risk of damage. The thermal foldback function reduces output power if the amplifier device starts to overheat. Under-voltage, overvoltage, and short-circuit protection, as well as thermal shutdown, are also included. A low quiescent current of just 10mA helps to further conserve battery charge.