Chinese audio IC difficult to break through, luck + experience + culture?!

Pan, technical director of Tianjin Rui Yin Technology Co., Ltd.

Electronic enthusiasts Network: audio technology in the consumer market application is not uncommon, I believe that everyone is not unfamiliar with audio products-high-fidelity (HiFi) audio, car audio, subwoofer, cell phone speakers, headphones and so on. Now a bit HiFi audio field experts say that audio is actually not as simple as imagined, "bad to do, the water is very deep!" "The product can be made in half by luck and by experience." Pan, a technical director from Tianjin Rui Yin Technology Co., Ltd. expressed the above views. The field of audio technology seems simple, why is it so difficult to enter or develop? Where are the key points of audio design? This Pan as an electronic enthusiast interview expert guests, will be mainly on the audio design and chip design enterprise communication problems, audio products market trends, audio design difficulties, the future of technical highlights such as one to make a point of view.

Electronic enthusiasts Network: machine manufacturers and IC design company design Department communication barriers? What are the main ones? What are the effects of these barriers? How do you think IC design company can design a chip suitable for the whole manufacturer? What are the specific recommendations?

Pan: I have previously on the machine manufacturers and IC design company design department to communicate this issue has written an article (see the report: Audio system chip Select a number of performance parameters detailed), which seriously criticized the domestic chip design manufacturers. They think that the audio is not a complex system, not to communicate with us, this is a very headache. They (some domestic IC manufacturers) believe that video can be done, audio is not a problem. The problem is that the video does not appear, the audio will appear. To give a simple example, in the video from the actual effect, the human eye 25 frames per second can see the smooth picture, even if there is a millisecond of data is not connected, it is difficult for the human eye to detect, and audio as long as a few microseconds intermittent, sound will obviously feel uncomfortable.

At present, domestic and foreign manufacturers out of the embedded Development Board/Evaluation Board does not have the ability to decode High-definition audio, the main problem is that the clock frequency is not followed, such as the chip can be divided into the internal output of 192k sampling rate out of the one can do. So, do audio product development is half the luck component, hit the bad chip product is over, this is not experience can make up. I think the IC design company should design a chip suitable for the whole manufacturer, like the earlier we communicate with an IC design company in Zhuhai, they will accept the proposal, do not affect the overall function of the chip structure on the basis of some parameters to adjust, such as FIFO depth is not enough, they will help to make the corresponding adjustment.

Electronic enthusiast Network: As an expert in hifi/audio field, what do you think is the most important thing in building an audio system? With the right chip, how to design a good overall performance of the audio system? What are the measures?

Pan: In the construction of audio system, the most important chip selection is CPU frequency, system memory size, and i2s FIFO depth is sufficient. For instance, CPU integrated PLL (PLL) produced by the clock quality is very poor, the clock will directly affect its poor quality, and the vast majority of the CPU is from the PLL clock frequency to the chip subsystem, I2S is a chip in one of the subsystems, And we choose to pay attention to the I2S support does not support the passive clock, no passive clock we will not adopt. This is also the current HD video can not do hifi one reason, because many of these chips do not have a passive clock (also called from the clock) this function. To design a good overall performance of the audio system will first have to do the clock part. The second is more critical to pay attention to PCB design wiring and alignment, this part of the design of the basic and design of RF circuit is quite, the requirements are particularly prominent. A certain signal line if line wrong or wiring is not standardized, and even the changes in the PCB plate thickness, a poor consistency of the gold, will affect the entire audio system output quality, and these problems, the current test instruments and testing methods can not be tested.