Silabs公司的Si824x系列是两路隔离的驱动器,输入和输出以及输出间绝缘,峰值电流为0.5 A (Si8241)和4.0 A (Si8244) ,最大音频功率30W,工作最高电压为24V, Si824x还集成了死区发生器,以获得最佳的THD,主要用在D类音频放大器.本文介绍了Si824x主要特性,方框图, D类音频放大器方框图,半桥音频应用框图以及Si824x D类音频放大器参考设计电路图和材料清单(BOM).
The Si824x isolated driver family combines two isolated drivers in a single package. The Si8241/44 are high-side/low-side drivers specifically targeted at high-power (>30 W) audio applications. Versions with peak output currents of 0.5 A (Si8241) and 4.0 A (Si8244) are available. All drivers operate with a maximum supply voltage of 24 V.
Based on Silicon Labs’proprietary isolation technology, the Si824x audio drivers incorporate input-to-output and output-to-output isolation, which enables leveltranslation
of signals without additional external circuits as well as use of bipolar supply voltage up to ±750 V. The Si824x audio drivers feature an integrated deadtime generator that provides highly precise control for achieving optimal THD.
These products also have overlap protection that safeguards against shootthrough current damage. The CMOS based design also provides robust immunity from latch-up and high-voltage transients. The extremely low propagation delays enable faster modulation frequencies for an enhanced audio experience. The TTL level compatible inputs with >400 mV hysteresis are available in PWM input configuration; other options include UVLO levels of 8 V or 10 V. These products are available in narrow body SOIC packages。
Si824x主要特性：
0.5 A peak output (Si8241)
4.0 A peak output (Si8244)
PWM input
High-precision linear programmable dead-time generator 0.4 ns to 1 μs
High latchup immunity >100 V/ns
Up to 1500 Vrms output-output isolation, supply voltage of ±750 V
Input to output isolation for low noise (up to 2500 V)
Up to 8 MHz operation
Wide operating range
–40 to +125℃
Transient immunity >30 kV/μs
RoHS-compliant
SOIC-16 narrow body
Si824x应用：
Class D audio amplifiers
图1.Si824x方框图
图2.Si824x在半桥音频应用框图
Si824x D类音频放大器参考设计
Si824xClassD-KIT
Audio Class D amplifier reference design, a stereo, two-state, halfbridge Class D amplifier leverags the performance advantages of the Si8241 ISOdriver. This two-channel Class D Audio Amplifier delivers 120 W per channel into 8 Ω, while enabling < 0.02% THD at 60 W and > 95 dB SNR. The Class D reference design architecture uses a phase-shift, self oscillating modulation approach that is capable of achieving far greater signal-to-noise ratio than clock driven amplifiers. This self oscillating implementation eliminates the circuitry necessary to generate the triangle waveform. To keep the circuit as simple as possible, a two-state, half-bridge is implemented and exemplifies the benefits of using the Si8241 Audio Gate Driver.
图3.Si824x D类音频驱动器方框图
图4.采用Si8241的D类音频放大器方框图
图5.Si824x D类KIT外形图
图6.Si8241 音频栅极驱动器电路图
图7.过流保护电路图
图8.Si824x D类音频放大器参考设计电路图(1)
图9.Si824x D类音频放大器参考设计电路图(2)
Si824x D类音频放大器参考设计材清单(BOM):
我司长期专注于D类功放IC推广和销售，详细的产品资料请查阅：http://www.szczkjgs.com/tech.htm
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