On Semi NCS8353立体声每路20W D类功率放大方案
2011-07-07
作者:On Semi公司
On Semi公司的NCS8353是立体声每路输出20W的D类音频功率放大器,具有可编程" title="可编程">可编程程的功率限制和可选择的增益: 20 dB, 26 dB, 32 dB, 36 dB。NCS8353的效率高达86%,每路的输出功率限制有10W,12W,15W和20W.工作电压8 V 到26 V,主要用在平板电视机和有源扬声器。本文介绍了NCS8353主要特性,基本方框图和8欧姆扬声器典型应用电路图。
Stereo 20W/Ch Class D Audio Power Amplifier with Programmable Power Limit and Selectable Gain
The NCS8353 is a stereo Class D audio power amplifier capable of delivering a continuous power of up to 20 W/ch into an 8ohm bridge tied load (BTL). It can be powered from the existing 24 V rail in Flat Panel Television (FPTV) systems. The high efficiency of the NCS8353, 86%, reduces the requirement of an external heat sink when driving
high power.
The digital power limit feature can program the output power limit at 10 W, 12 W, 15 W, or 20 W/ch, allowing the NCS8353 to be a single system solution in FPTV audio applications.
The NCS8353 includes a digital power limit feature. The digital power limiter quickly reduces the internal gain of the amplifier when high amplitude signals would cause excessive clipping on the output.
The NCS8353 minimizes pop and click artifacts in the audio system by reducing voltage and current transients during power supply cycling, entering or recovering from shutdown, and mute. The shutdown feature reduces the quiescent current draw of the amplifier
to 100u NCS8353uA typical. The mute feature ensures that audio is not present at the output during audio source switching.
The gain of the NCS8353 is programmed via two gain pins, G0 and G1, allowing four selectable ranges: 20 dB, 26 dB, 32 dB, and 36 dB.
Auto recovery short circuit and over temperature protection circuitry are incorporated to ensure device functionality after short circuit and high temperature events occur.
NCS8353主要特性:
Powered from 8 V to 26 V to include FPTV Backlight Supply (24 V 5%)
Digital Power Limiter Controlled by Two External bits: 10 W, 12 W,
15 W,or 20 W per Channel
♦Allows for Maximum System Flexibility
♦Reduces Distortion with Excessive Inputs
Pop and Click Suppression
Selectable Gain: 20 dB, 26 dB, 32 dB, 36 dB
High Efficiency Eliminates the Need for External Heat Sink
Low Supply Current: IQ = 100uA Typical During Shutdown at 12 V
Mute Function
Auto−recovery Short−Circuit Protection
Over Temperature Protection
Fully Differential Architecture
This is a Pb−Free Device
NCS8353典型应用:
Flat Panel Television (FPTV)
Powered Speakers
图1。NCS8353基本方框图
图2。NCS8353 8欧姆扬声器典型应用电路图
详情请见:
http://www.onsemi.cn/pub_link/Collateral/NCS8353-D.PDF