Si824x Isolated Gate Driver, for Class D Applications with Up to 1000W Output Power
Provides excellent audio performance
Silicon Laboratories Inc. (NASDAQ: SLAB), a global specialist in high-performance analog-intensive mixed-signal ICs, announced the launch of the Si824x family of isolated gate drivers designed for high-power Class D audio systems ranging from 30W to 1,000W. The new Si824x Class D audio driver family provides outstanding high-fidelity performance, robust noise immunity, and precise dead-time control for a diverse range of digital audio applications, such as home entertainment systems, powered speakers, guitar amplifiers, public address (PA) and outdoor speaker systems, alarms and sirens, and car audio.

Class D amplifiers, the best solution for low-power audio design, are rapidly replacing Class AB amplifiers in high-power applications. As the adoption of digital audio technology and high-efficiency standards increases in the Hi-Fi market, developers are creating energy-efficient 'green' systems that meet Energy Star standards while enabling superior audio performance and reduced BOM costs. Silicon Labs' Si824x audio driver provides an ideal solution for these emerging high-power Class D audio designs.

Digital signals in high-power Class D designs require precise 'dead time' control between pull-up and pull-down stages for performance optimization. If the dead time is too short, power is wasted, and if it is too long, total harmonic distortion (THD) increases. Optimal dead time control is critical for achieving the very low THD performance required in high-performance audio systems. While other competing audio driver products offer limited performance for dead time adjustment, the Si824x IC supports precise dead time control based on the value of an external resistor. Developers can simply adjust dead time by changing the resistor value, thereby meeting the requirements of various audio designs.

Based on Silicon Labs' proven digital isolation technology, the Si824x audio driver provides high-voltage isolation of up to 2.5 kV between the input and output stages, allowing the input stage to be driven by a low-voltage Class D control signal while the output drives high-voltage, high-current output stage transistors. By isolating the input stage from the output stage, errors in sensitive signals caused by noise or transient voltages are prevented. With high-side and low-side outputs isolated from each other and capable of driving up to 1500 V, the Si824x IC can support the requirements of high-power audio.

Through the isolation of input and output stages, the Si824x architecture offers the benefits of built-in level shifting. The isolated architecture of the gate driver enables audio systems to smoothly interact between the low-voltage DSP/modulator stage and the high-voltage power stage without the need for any additional BOM components. Additionally, the power voltage is selectable, which is another advantage of this product as it eliminates the need for the expensive DC blocking capacitors typically required in competing systems.

The Si824x driver, designed to operate in noisy environments, generates 'latch-up' that causes device damage.