V3Link

V3Link is a SerDes interface used for industrial applications. This link requires a reliable clock with well-controlled jitter. SiTime offers robust low-jitter clocks in small footprints that meet V3Link requirements with significant margin to support the reliable transfer of high-definition data over long distances and in harsh environments.

Download Application Brief

V3Link requires a single-ended LVCMOS clock, provided by an oscillator such as the SiT8208. The clock frequency depends on various factors such as image resolution, frame rate, or V3Link clocking mode. Clock jitter must be well controlled. Excessive jitter on the clock "closes the eye diagram", resulting in increased bit error rate (BER) on the link.

Asynchronous V3Link clocking

Asynchronous mode represents the traditional way of driving serial data interfaces: both clock + data are provided at the input of the serializer. After transmission, both clock and data are recovered at the deserializer. Because multiple, independent links each run with its own independent clock, this mode is called asynchronous.

Synchronous V3Link clocking

In synchronous mode, the clock is provided from an oscillator to the deserializer side of the V3Link. The clock is then transmitted "uplink" through the V3Link backchannel to the serializer. This mode is called synchronous because the link runs synchronously to the deserializer and multiple links are therefore synchronized.

Synchronizing multiple V3Link with a SiTime clock generator

When multiple cameras are synchronized, their frames are aligned. This reduces the need for a RAM buffer on the image signal processor side, otherwise needed to re-align mismatched video frames. Having all clocks at the same frequency and phase is a prerequisite for synchronizing multiple links.

Up to four cameras can be connected to a V3Link deserializer. When more cameras are needed in a system, a SiTime clock generator can be used to synchronize all clocks toward multiple deserializers. Clock generators can also provide other clocks in a system (such as PCI-Express, Ethernet, etc.), offering all advantages of integration.

SiTime Timing Solutions Advantages

SiTime devices offer the following advantages over quartz crystals:

• Up to 50x better reliability.
• Up to 100x better resilience to shock, vibration and electromagnetic interference, due to the smaller size (0.4 x 0.4 mm) and lower mass of MEMS resonators compared to crystals.
• EMI reduction features including drive strength selection and spread spectrum clocking (select devices).
• Small footprint, enabled by the small size of the MEMS resonator.
• Factory-programmed devices from standard parts enable short lead time and security of supply.
• Reliable semiconductor supply chain.

Resources

• Timing solutions for industrial
• MEMS Timing for FPD-Link
• Resilience and Reliability of Silicon MEMS Oscillators