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Application of Femtosecond Crystal Oscillators in High - end DAC Decoders and Players

2025-01-15

The core component responsible for digital - to - analog conversion in electro - acoustic playback systems is the DAC chip. Since the 1970s, monolithic integrated circuit (IC) DACs have emerged, marking the beginning of the DAC chip era.

Mainstream DAC Chips

AKM
AKM is a Japanese chip manufacturer (Asahi Kasei Microdevices Corporation). Besides the well - known TCXO chips, its audio decoding chips are also top - notch. Currently, AKM has introduced a separated solution of modulation (AK4191) and decoding (AK4499EX), and added an asynchronous mode option. In AK4191, a FIFO (First - In - First - Out) memory is installed to buffer data when the audio signal rate and the local rate are out of sync, enabling asynchronous continuous playback. In this way, it is decoupled from the audio signal, and the impact of Jitter only depends on the performance of the local crystal oscillator. The AK4191 + AK4499EX solution has obvious advantages over the previous AK4499 chip. Although the former is a two - channel design, it can achieve the performance level of the latter's four - channel design, and it also has a lower price.
ESS
ESS has also launched many new products, such as ES9017, ES9027PRO, ES9039PRO, etc. These products not only improve audio performance but also consume less power. Some of them integrate an MQA renderer, like ES9068A, ES9039MPRO, etc., which are used to directly decode MQA - format audio signals in hardware. Others add an I/V (current - to - voltage) conversion and a line - drive module, such as ES9080, ES9033, etc., increasing the integration level and reducing the overall PCB area and complexity of the device. Most high - end DAC chips of ESS have an asynchronous mode and a Jitter elimination circuit.
CL
Meanwhile, CL has launched new products CS4302P/04P/08P, which are two - channel, four - channel, and eight - channel chips respectively. They support PCM32 - bit 768Hz and DSD512, and their performance has been significantly improved compared with the previous generation.

Ranking of Mainstream DAC Chips

Application of Femtosecond Dual Crystal Oscillators in High - end Decoders and Players

Currently, high - end DACs and players have all chosen two high - precision, ultra - low phase - noise, and low - jitter crystal oscillators, with frequencies of 45.1584MHz and 49.152MHz respectively.

The 45.1584MHz crystal oscillator corresponds to tracks with frequencies of 44.1kHz, 88.2kHz, 176.4kHz, and 352.8kHz.
The 49.152MHz crystal oscillator corresponds to tracks with frequencies of 48kHz, 96kHz, 192kHz, and 384kHz.
Tracks with different encoding frequencies are processed in integer multiples by different crystal oscillators, bypassing fractional conversion and ensuring Hi - Fi sound quality.

Excellent Performance of Femtosecond Crystal Oscillators

For audio - used crystal oscillators, the industry usually uses an integration range of 10 - 1MHz, while communication - used crystal oscillators often focus on their performance within the bandwidth of 12kHz - 20MHz.

In the "femtosecond crystal oscillators" CO22H4 - 49.152 - 33KDTST - LJ and CO22H4 - 45.1584 - 33KDTST - LJ of Hangjing, which are widely used in high - end portable Hi - Fi players, we have provided the Jitter values under these two integration bandwidths. The Jitter value within 10kHz - 1MHz is less than 100fs.

The application of ultra - low - jitter crystal oscillators significantly reduces the jitter and distortion of audio data, enabling accurate sound reproduction and clear presentation of every detail.

润色这段英文使其更符合专业文献的风格

展开介绍一下飞秒晶振的工作原理

飞秒晶振在其他领域有哪些应用？

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Concentric peers, create brilliance together - HCI Hangjing's 10th Anniversary Team Building Annual Meeting was successfully completed!

Application of Constant Temperature Crystal Oscillator OCXO in Radar

Concentric peers, create brilliance together - HCI Hangjing's 10th Anniversary Team Building Annual Meeting was successfully completed!