MP3, the original aristocratic product, has been accepted by the public. However, the price of MP3 in the market is confusing. How can some MP3 players with the same size 128M cost thousands of dollars, while others only cost 300 dollars? What is the reason for the huge price difference? Here's how to solve the puzzle from the MP3 decoding chip.
Before introducing the decoding chip, let's first understand the working principle of MP3: firstly, take the MP3 song file out of the memory (flash memory medium, hard disk medium and CD medium), read the signal in the memory → decode the signal by the decoding chip → convert the solved digital signal into an analog signal through a digital-to-analog converter → amplify the converted analog audio → low-pass filter it and send it to the headphone output port, and then the music we hear will be output.
The decoding chip, as its name implies, is to decode MP3 files on the memory. To a great extent, it determines the final sound quality performance. MP3 is a lossy compression format. If MP3 player has excellent decoding chip, it can better restore the quality of audio signal and make up for the loss of audio signal to a great extent. On the contrary, the low-end decoding chip will further lose the encoding information of MP3. At present, the most common chips in MP3 players on the market are Sigmatel, Actions, Sunplus (Sunplus), MosArt (Medium Silicon), Atmel, Telechip, Philips and so on. , and the most common chips are: SAA 7750/SAA 7751PNX 010/06. Stmp3410/3420/1342 from Sigmatel, TCC730/TCC73 1 from telechips and SPC A514A/SPCA751A from Lingyang are the mainstream models.
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PP5020
Representative products: iPod Mini, iPod Photo, iRiver H 10.
Main functions:
Ability to copy, view, edit and modify images without a PC;
Support PictBridge standard, and can print directly on HP and Canon printers without PC;
It supports the direct transmission of the images inside the digital camera to the player anytime and anywhere, and supports the high-speed USB 2.0 transmission protocol;
Be able to connect TV and play images (JPG, GIF and TIFF) and videos (MPEG) in the player;
You can listen to music directly in mainstream online music services such as MusicMatch, Napster and RealAudio, or listen to audio books on Audible.com.
Automatically networking, identifying music labels and generating playlists through online Gracenote music service;
Record captions for the images collected in the player, and add background music from the same player.
Suggest matching headphones: Koss KSC35, PX 100, ATH-CM3, ATH-EQ33, Goethe sr60, Motorola SCF5249.
Representative products: iRiver H320, M5 Cowen, MPIO HD200.
SCF5249 is a single-chip product that integrates the sound decoding of DSP and the system management function of microcontroller, so it is more competitive than other non-single-chip products in system development cost and overall power consumption performance.
The battery life of this SCF5249 is 40 hours, far exceeding the current industry standard of 30 hours. It also supports many different decoding and file formats, including compact discs, flash cards, micro hard drives, etc. In this way, portable audio equipment with this product can be used not only as personal audio equipment, but also as walkman, portable MP3 and CD-ROM platforms.
SCF5249 also supports different music formats, including MP3, WMA, AAC and so on. So as to meet the different music needs of consumers simultaneously. Considering the scalability of different music formats in the future, it can be further expanded by upgrading with this single-chip product.
SCF5249 is based on Motorola's 32-bit CordFire kernel, which makes it have the functions of audio decoding and file management at the same time, and supports various decoding and file formats. At the same time, it is equipped with an integrated SDRAM controller, which can support DRAM synchronously and access external data content quickly. This single-chip product can also support flash memory devices such as MMC and CF.
Suggestions for using headphones: b &；; O A8, ATH-CM5 (Discman with general quality)
Texas instruments: TMS320DA2XX
Representative products: innovative and creative Zen
I don't need to say more about the power of this chip. Choose if you have money.
Headphones are recommended: Sony 838 or above or ATH-CM or above.
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Sigmatel 34 10/3420
Representative products: Samsung Sumsung 55H, MSC ha 128, JNC SSF800.
If we want to talk about the current market share of MP3 chips, the Sigmatel family in the United States certainly deserves it, but the quality of Sigmatel chips is always different. Generally speaking, MP3 of Sigmatel decoding chip will be quite satisfactory in sound quality, bright in sound, mediocre in midrange, lacking in bass sense and stiff in treble, and inferior to Philips and Telechips in music performance.
This kind of chip has average sound quality and is mostly used in middle and low-grade products. At present, the scheme of using SigmaTel 34 10 chip is very mature, but if the peripheral circuit is not designed more, its sound quality will be very general. This is why although there are many products using this chip, the sound quality performance is different.
Sigmatel 3420 is more like an upgraded version of Sigmatel 34 10. Compared with STMP34 10, which does not support MP3 hardware coding, the processing speed is slow. Sigmatel 3420 adds support for USB2.0 on the basis of Sigmatel 34 10. Fixed the incompatibility between Sigmatel 34 10 and USB2.0 of some motherboards, added MP3 hardware coding function, and improved the sound quality compared with Sigmatel 34 10.
Headphones are recommended: original headphones are enough, and using too high-end headphones will waste resources.
Sigmatel 35XX
Compared with Sigmatel 34 10, Sigmatel 35 10 not only supports USB2. 0, and improve the overall energy management, support the detection of battery charging function, strengthen the digital-to-analog converter and the music amplifier circuit of headphones, and have the ability of subdirectory management. It can be said that the development of Sigmatel family chips to Sigmatel 3520 has taken a big step.
Sigmatel 3520 has improved the shortcomings of Sigmatel 34101342, such as ordinary midrange performance and stiff treble, with clear sound quality and signal-to-noise ratio of 95dB. Added MP3 hardware coding, FM radio and USB2. 0 and other functions; The processing speed of Sigmatel 3520 is also higher than the previous generation, reaching 75 MHz (65MHz for 34xx series). At present, there is the shadow of Sigmatel 3520 chip in MP3 at all price points on the market, which also shows the great progress of Sigmatel 3520 chip.
It is said that Sigmatel 3502, which is aimed at the high-end market, has greatly improved the design of chips and peripheral circuits, and is known as the third generation decoding chip. It improves the main frequency of DSP digital signal processor to 75MHz, the signal-to-noise ratio reaches 95db, the output power reaches 1 1mW, and the total harmonic distortion rate is less than 0.05%.
The differences between Sigmatel 34XX and Sigmatel 35XX series are mainly in the following two aspects: USB 1. 1 upgraded to USB2.0；; The battery life has increased, such as the innovative TX-FM, which can play continuously for 1 5 hours with the 7th battery.
Suggest matching headphones: innovative HQ-65, Philips HE26 1, Sony E828LP.
Philips saa775x/pnx0101et/pnx0102.
Representative products: WeWa voice of the king, super magic sound series.
If we must judge the best MP3 decoding chip on the market at present, it is undoubtedly Philips' chip. The decoding chip of Philips family has always been known as "full function, good sound quality and high price" in the industry.
Philips SAA775x chip is one of the most common (supporting CD direct recording) and effective decoding chips in MP3 player decoding chipset on the market at present. The sound quality of the decoding chip is as follows: the bass sinks deeply, the midrange is excellent, and the treble is average.
Because SAA775x includes DSP (Digital Signal Processing) and 32-bit ARM RISC processor, it can work with ultra-high integration single chip, such as audio decoding and speech coding, and can be protected by SDMI (Secure Digital Music Initiative).
SAA7750 includes DSP and 32-bit ARM RISC processor, and the signal-to-noise ratio is 90dB. The chip is compatible with multi-stage and multi-file EQ intelligent sound effects, supports ADPCM format to save voice records, synchronously display song titles and information, and directly record in Line-in, and also supports USB 1. 1/2。 0 standard, supporting decoding of multiple music formats. However, SAA775 1 only has a DSP core and a flash memory, excluding the audio multimedia decoder, so it can only be used for the upgradeable MP3 CD player. SAA7752 is a price-oriented solution, which only contains DPS chip and uses external memory to store data, mainly for CD walkman. As for SAA7753, only the DSP chip has been changed more thoroughly. It just replaces flash memory with embedded memory, which corresponds to a low-cost CD player system as an additional MP3 function.
The embedded processor used by Philips SAA775x has advanced energy management function, which can control the running speed of the processor according to the workload to extend the battery life, similar to the energy-saving technology commonly used in high-end PDA and notebook computers. Therefore, when SAA775x chip plays 128Kbps MP3 at normal volume, the power supply time of a single AA battery can be as long as 24 hours. Of course, this is the theoretical working time of the chip. For MP3 players, due to the limitation of production technology, the specific working hours are another matter.
PNX0 10x series decoding chips are also a large series, including PNX0 10 1, PNX0 102, PNX0 105. Among them, PNX0 102 and PNX0 102 are products specially developed for flash MP3 walkman, while PNX0 105 is products for hard disk multimedia players.
PNX0 10 1 embeds 4Mbit programmable FLASH, and only supports USB 1. 1. At present, all USB2.0 interfaces equipped with MP3 chips PNX0 10 1 are realized by adding USB2.0 control chips. (Note: When used with Molex, USB2 can be supported. 0, SD/MMC extension, etc. ) and PNX0 102 embeds 8mb programmable FLASH, which provides support for USB2.0. PNX0 105 also supports USB2.0, GDMA, IDE(ATA/ATAPI/PC card) and other interfaces, but there is no embedded programmable FLASH.
Headphones are recommended: Sennheiser MX500 or above, Sony E888, Intemet ER6.
Telchips TCC73X/TCC72X
The South Korean Telechips decoding chip, which went on the market only last year, won unanimous praise as soon as it came out and grew rapidly with the strong support of many Korean manufacturers. In terms of function, performance and sound quality, Telechips TCC730/73 1 is indeed better than Sigmatel's STMP34 10, with sufficient bass sense, balanced performance in all frequency bands and wider sound stage. However, there is still a certain gap compared with Philips SAA7750/775 1. In addition, although Telechips TCC730 is a little cheaper than SAA7750, it needs external ROM and many peripheral components, so there are few exquisite MP3 products using this chip.
Generally speaking, the performance of Telechips is between Sigmatel STMP34 10 and SAA7750/775 1 series. On the basis of its own sound quality, MP3 with this chip will be improved if it is equipped with more advanced headphones. This kind of machine usually comes standard with Sennheiser MX300 (or OEM Sennheiser) headphones, which belong to the most popular headphones in Sennheiser MX series, so it is suggested that friends who have higher requirements on sound quality can try Sennheiser MX500, or higher-grade KOSSP/KOSSP and Sennheiser PX 100/PX200. Because the MP3 with this chip has a certain potential in sound quality, unlike what all dealers told you, the sound quality of all MP3 players has improved after replacing high-end headphones. In fact, there is no room for exploring the sound quality of some MP3 players due to the limitations of their own chips, designs and manufacturing processes.
Suggest matching headphones: Sony Q55SL, Sony E888.
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Ruixin products >> digital audio and video processing chip
The RK26XX series of digital audio and video processing chips of Credit Suisse is a digital audio and video processing chip that supports MPEG-4 video decoding and playback function. It is manufactured by 0. 18 micron process and can be applied to portable MP3 player products with MP4 playback function. RK26XX series chips adopt a highly integrated mixed digital-analog design, integrating a 32-bit DSP core, 16-bit ADC and 18-bit DAC. This chip is an ideal solution for customers to develop portable multimedia products supporting MPEG-4 playback, such as portable digital audio and video players and digital foreign language learning machines, with high cost performance. RK26XX can decode and play MPEG-4 video files with low frequency and low power consumption, and the picture quality is clear and smooth. At the same time, RK26XX integrates a large number of I/O control interfaces to provide maximum application flexibility. The low power consumption performance of RK26XX can prolong the battery life of portable players, and its integrated intelligent lithium battery charger supports voltage control (AVC), which saves system power consumption compared with similar products. The integrated power management unit includes an efficient on-chip DC-DC converter, which supports various battery configurations, such as 1×AA, 1×AAA and lithium-ion batteries. In addition, compared with the traditional voltage control system, AVC enables the chip to work at a higher peak CPU frequency, thus achieving the highest running speed of 100 MIPS. RK26XX supports the digital rights management technology based on Microsoft DRM 10, and at the same time, Credit Suisse's software development tools also integrate other advanced functions specifically for RK26XX, which helps to speed up customers' design. RK26XX has the function of supporting multi-tasks, and can realize the product functions of listening to music, reading e-books and playing games. RK26XX chip integrates USB 2.0 high-speed/full-speed PHY, and the transmission speed is faster. The controller supporting TFT/CSTN/ OLED color screen is integrated.
RK27XX adopts a more advanced dual-core architecture of ARM+DSP, which can simultaneously carry the operating system and low-power high-speed digital signal processing algorithm, and is the most powerful MP3 solution at present. RK27XX video has more comprehensive compatibility, including AVI(XVID, DIVX), WMV and RMVB, on the basis of retaining all functions of RK26XX series, and can support smooth playback and FLASH animation with a resolution of up to D 1(720*480). Support for RA and ACC audio formats has been added, and the function of music media library has been newly introduced, which is convenient for users to manage a large number of music files. Support DC/DV, Bluetooth and 16-bit game functions; Embedded in the MiniOS operating system, you can develop personalized UI (picture overlay, perspective, fade in and out, etc. In addition, in order to cope with the development trend of portable multimedia technology to 3C convergence, RK27xx will have built-in HD radio or DAB function, and will also support GPS and mobile TV functions in the future.
Excellent features:
1. Video playback: supports video playback in MPEG-4 format.
2. Music playback: supports MPEG 1/2/2.5 layer 1/2/3 full-rate (8 kbps to 384 kbps) audio playback; Support WMA audio playback with bit rate of 32Kbps-320Kbps.
3. Image browsing: supports JPEG format image browsing.
4. Text reading: supports TXT text reading.
5. Live recording: Support live recording, built-in microphone and noise reduction. There are long-term recordings and high-quality recordings to choose from.
6.Line recording: supports the function of LINE IN line direct recording MP3 (supports multi-rate recording).
7. Lyrics display: the song title, singer and LRC lyrics are displayed synchronously.
8, a variety of sound effects: support 3D surround sound effects, support rock, pop, classical, jazz, bass and other sound effects, and provide users with DIY sound effects.
9.USB function: compatible with USB 2.0 high speed/full speed.
10, radio function: FM radio function (75MHz~ 108MHz) is provided to support campus broadcasting and radio function.
1 1. Display interface: supports STN/CSTN/TFT/ OLED, and PWM controls backlight brightness.
12. Spectral display: It has real spectral display function.
13, game function: At present, Tetris and Push Box games are built in.
14, multi-tasking function: you can listen to music, read e-books and play games at the same time.
15. Firmware upgrade: supports firmware upgrade and realizes the function expansion of this machine.
16. System language: supports simplified and traditional Chinese, English, Korean, Japanese, French and German.
17, multi-storage compatibility: support multi-brand multi-capacity flash memory and flash memory cards (SD card, Mini SD card, MMC card).