X-1 digital interface of our team to develop a high-performance USB digital audio interface, using the XMOS latest xCORE-200 series chips. X-1 is the rare Japanese KDS low jitter TCXO clock digital system interface. X-1 digital interface using standard USB2.0 input interface, while X-1 has a wealth of output interfaces, including coaxial RCA and I2S interfaces.
1.X-1 is the first use of XMOS latest xCORE-200 series USB interface digital products. New generation XMOS chip, using more advanced process technology, performance than the older U8 chip doubled, reaching 1000MIPS processing capabilities.
2.It is known, the core of the algorithm is heavy digital audio. Our team in the field of digital audio work for many years, at the same time get XMOS FAE support team, we conducted a number of technical improvements and optimization algorithms on the basis of the original firmware.
Each output interface supports sample rates:
PCM: 44.1KHz, 48KHz, 88.2KHz, 96KHz,
176.4KHz, 192KHz, 352.8KHz, 384KHz
DSD: 2.8 MHz (DSD64) - DoP, native
5.6 MHz (DSD128) - DoP, native
11.2 MHz (DSD256) - native
Bits wide: the highest 32 bit over I2S output
The highest 24 bit over S / PDIF
Each interface electrical standards:
1 . USB input socket is a standard USB-B type female, USB power supply range 4.5V-5.1V ;
2 . RCA connector outputs standard S / PDIF signal level is 550mV ( standard connection load ), the output impedance of 75 ohms;
1 . Carry out electricity as the mother of the acoustic design concept, pay attention to the power supply circuit design, high-performance, low noise and fast response of the LDO as the main power source. The entire board using a 2 -way independent of the LDO power supply, wherein the clock even partially adopted ADI 's ultra low noise LDO , in order to ensure the ultimate output performance laid a solid foundation.
2 .PCB motherboard with 4 -layer circuit board design, make sure you have a complete ground plane and power planes, high-speed digital design methods to ensure signal integrity and power integrity of the entire board. The clock signal special treatment, the use of package design and precise impedance control, thereby ensuring the signal quality and increase the clock anti-jamming capability. Input and output signals are to follow standard design, especially USB high speed signals using a 90 ohm differential impedance control.