Class D Audio Drivers

High-power audio systems are adopting digital audio technology and evolving toward lower-power, "green" products that meet Energy Star™ guidelines. Class D audio systems have begun penetrating the high-end markets, where low noise, extremely good THD performance and very high output power are required in consumer and industrial applications. The Si824x audio drivers are isolated Class D gate drivers that power audio systems delivering from 30 W up to 1000 W of audio power. See the sound quality performance of the Si824x audio driver over the audible spectrum using the Class D Sound Quality Demonstration.

Based on Silicon Labs’ proprietary isolation technology, the Si824x audio drivers incorporate input-to-output isolation, which enables level-translation of signals without additional external circuits. The Si824x audio drivers feature adjustable dead-time control for achieving optimal THD, overlap protection that safeguards against shoot-through current damage, robust immunity to latch-up and high-voltage transients, and lower BOM costs and PCB footprints compared to non-isolated gate drive solutions.

 Si824x audio drivers help achieve optimal sound quality in Class D applications

Class D Audio Driver Products

Family	Input Type	Outputs	Isolation Rating	Drive Strength	UVLO Voltage	Package
Si8241	PWM	High Side / Low Side	2.5 kVrms	0.5 A	8 or 10 V	NB SOIC-16
Si8244	PWM	High Side / Low Side	2.5 kVrms	4.0 A	8 or 10 V	NB SOIC-16
Si824x Reference Design

 

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Class D Audio Driver Features & Benefits

Key Feature	Benefit
Adjustable Dead-Time control	Enables precise synchronization of pull-up and pull-down signals to minimize THD
Input-to-output isolation	Enables level-shifting from input supply to output supply with no external components required Output voltage inherently supports 0 V reference, eliminating expensive DC-blocking capacitors High-voltage and low-voltage domains are electrically isolated, eliminating noise transfer between domains
High immunity to latch-up	Prevents system from going into destructive high-power modes due to voltage surges at either start-up or during operation Enables simpler system design with fewer BOM components
Ultra-low propagation delay	Supports modulation frequencies of up to 8 MHz Very low jitter enables robust system performance