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其实,3886生产商TI公司有份应用文档,AN-1192 Overture™ Series High Power Solutions;讲得很清楚,为什么并联,桥接,并联再桥接,这些都是基础知识,下来全面看下,基本上都有答案
文章开遍,
1 Introduction
Texas Instruments has a broad portfolio of monolithic power integrated circuits covering power levels from
a few hundred milliwatts up to 60W of non-clipped continuous average power. These ICs cover most
audio applications by themselves, however, for really high power applications, other methods need to be
employed because IC packages have limited power dissipation capabilities.
There are many different ways of obtaining over 100W of output power. Most high-end power amplifier
manufacturers utilize discrete circuits which allows them to market their amplifiers as “specially designed.”
However, there is a price to be paid for discrete amplifier designs; they are complex, difficult to design,
require many components, lack the comprehensive protection mechanisms of integrated circuits and are
not as reliable.
Other methods of obtaining output power greater than 100W include the use of power ICs as drivers for
discrete power transistors. There are a number of these types of circuits, but they too possess all of the
same flaws as discrete circuits, including a lack of comprehensive output stage protection.
2 Objective
The objective is to provide simple high-power solutions that are conservatively designed, highly reliable
and have low part count. This document provides three specific, but not unique, application circuits that
provide output power of 100W, 200W, and above. These circuits are the parallel, bridged, and
bridged/parallel configurations.
These three circuits are simple to understand, simple to build and require very few external components
compared to discrete power amplifier designs. Simplicity of design and few components make this solution
much more reliable than discrete amplifiers. In addition, these circuits inherently possess the full protection
of each individual IC that is very difficult and time consuming to design discretely. Finally, these circuits
are well known and have been in industry for years.
3 Conclusion
The BR100 (100W Bridged Circuit), PA100 (100W parallel circuit), and the BPA200 (200W
Bridged/Parallel Circuit) are high power solutions that can be used in many applications, but they are
primarily targeted for home theater amplifier applications such as powered subwoofers, self-powered
speakers, and surround sound amplifiers.
While bridged amplifier configurations are able to provide high power levels, they also consume four times
more power than a conventional single-ended solution. However, it is feasible to conservatively design a
100W bridged amplifier solution, as will be shown here. The bridged solution is designed to drive an 8Ω
nominal load for self-powered speaker or powered subwoofer applications.
The parallel amplifier is another configuration that can be used to obtain higher output power levels by
combining two IC outputs and doubling output current drive capability. The parallel topology provides a
great way of achieving higher power levels while keeping within IC power dissipation limits by driving low
impedance loads, which is the case for many self-powered speaker and powered subwoofer designs. The
main advantage of the parallel configuration is its ability to divide total power dissipation between ICs,
since each amplifier is providing half of the load current. Another advantage of the parallel design is that
unlike the bridge design, more than two ICs can be used. In fact, any number of ICs can be used in a
parallel design and when configured the same will share the power dissipation equally. For example, using
four ICs to drive a 1Ω load means that each IC dissipates 1/4 of the total power dissipation. In other
words, the load to each IC looks like a 4Ω load (Number Of ICs in Parallel * Load Impedance = Load
Impedance seen by each individual IC.) Odd numbers of ICs can also be used.
For lower impedance loads (<8Ω), the parallel circuit is a good solution for 100W power levels using just
two devices. Power levels above 100W may be obtained by using more than two devices to increase
output current capability and power dissipation limits along with lower impedance loads.
大家可借翻译软件,应可理解 |
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发表于 2022-5-16 10:53
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