Maximizing PCB wiring flexibility
Integrated the entire clock tree into a single IC
Silicon Labs has expanded its Si5332 arbitrary frequency clock family by releasing a new version that simplifies board layout and design by integrating a clock IC and a quartz crystal reference into a single package.

Unlike existing solutions that can cause interoperability issues when clock ICs and crystals are supplied by third-party manufacturers, the new all-in-one Si5332 solution guarantees reliable startup and operation for the entire product lifespan. Along with this, Silicon Labs introduced multi-profile support applicable to the entire Si5332 product family. Using this feature, developers can support multiple clock tree configurations with a single part number.

Traditional clock generators use an external discrete quartz crystal frequency reference. This crystal interface circuit must be carefully designed, taking capacitive loads into account, to ensure accurate clock synthesis. To minimize noise coupling issues, designers generally avoid routing high-speed signals close to the crystal, which limits the flexibility of PCB wiring.

The Si5332 clock generator resolves design constraints by integrating the crystal reference inside the package. In addition to simplifying the design, this approach minimizes the overall PCB footprint and maximizes PCB wiring flexibility. Because this crystal is shielded from external PCB noise, the Si5332 device with the crystal integrated (175fs RMS 12kHz~20MHz) provides lower jitter compared to the Si5332 version using an external source (190fs RMS).

The Si5332 clock generator utilizes Silicon Labs' MultiSynth technology to provide arbitrary frequency and output clock synthesis capabilities, as well as high jitter performance. Supporting up to 12 clock outputs, selectable signal formats per output clock (LVDS, LVPECL, HCSL, LVCMOS), and independent 1.8V–3.3V VDDOs, the Si5332 can be connected to a wide range of FPGAs, ASICs, Ethernet switches/PHYs, processors, SoCs, and high-speed SerDes, including PCIe. The Si5332 enables the integration of the entire clock tree into a single IC.

The new multi-profile feature elevates the device's integration level to a new level, enabling the integration of up to 16 unique clock tree configurations into a single IC. Developers can now replace Crystal Oscillator (XO) + Buffer, Clock Generator, and Clock Generator + Buffer clock trees with a single Si5332 part number. Since each unique configuration can be selected using hardware pins, there is no need to use the serial interface to reconfigure the device to support different frequencies. Instead of procuring different timing devices for different frequency combinations, this multi-profile feature makes it easy to verify the device with a single part number across different platforms and designs.

The Si5332 clock generator is supported by Silicon Labs' CBPro (ClockBuilder Pro) software, which simplifies device setup and customization. With CBPro, customers can customize clock solutions to their specific requirements and receive samples within a minimum of two weeks. CBPro generates custom part numbers for each device without minimum order quantity (MOQ), initial development costs (NRE), or other constraints.

Silicon Labs' Si5332 clock generator is currently available in both sample and production quantities, with a choice of 32/40/48-pin QFN packages and 6/8/12 output options. Pricing starts at $4.67 per unit (USD) based on a quantity of 10,000. Silicon Labs offers various evaluation boards (EVBs) to accelerate device evaluation and development. The price for clock and oscillator EVBs ranges from $149 to $199 (USD MSRP).

James Wilson, General Manager of Timing Products at Silicon Labs, said, “The Si5332 clock generator provides the industry’s best level of timing integration, enabling complete clock tree integration for 10/25/100G data centers as well as telecommunications, industrial, and broadcast video applications,” adding, “This comprehensive timing solution reduces supply chain complexity because it is supplied by a single manufacturer.”