Any-rate clock generators are the industry’s first clocks targeting cost-sensitive applications
- click to enlarge
The Si5355/56 any-rate clock generators are the industry’s first clocks targeting cost-sensitive communications, computing and general purpose applications capable of synthesizing four completely non-integer related frequencies up to 200 MHz. The device has four banks of outputs; each bank supports two CMOS outputs at the same frequency. All outputs are guaranteed to have 0 ppm frequency synthesis error regardless of configuration, enabling the replacement of multiple clock ICs and crystal oscillators with a single device. Through a flexible web configuration utility called ClockBuilder™, factory-customized pin-controlled Si5355 devices are available in less than two weeks. By providing made-to-order, frequency flexible clock generators with short lead times, you can leverage the benefits of a custom clock solution which provides simpler design, faster time to market and lower BOM costs.
The key feature supported by the Si5356 is spread spectrum clock generation, a technique used to reduce electromagnetic interference (EMI) noise and ensure compliance with FCC regulations regarding peak emissions. Spread spectrum clocking (SSC) reduces the RF energy peak of the clock signal by modulating its frequency and spreading the energy over a broader frequency range. The Si5356 supports the two spread spectrum techniques common in the industry, center spread and down spread. The Si5356 uses a triangle modulation profile, a common profile for SSC applications. If system-level EMI testing confirms that spread spectrum is required by an application, it can be simply enabled by pin selection without the need for component or firmware changes, simplifying qualification testing and shortening the overall development cycle.
ClockBuilder enables mass customization of clock generators and allows the use of a broad range of application-specific clocks that minimize BOM costs while significantly reducing design and layout complexity. Custom versions of the Si5355 are made to order by programming the frequency plan into non-volatile memory at outgoing test. This eliminates the need for metal mask changes required by traditional clock ICs.
ClockBuilderTM key features
- Provides custom, application-specific clocks in two weeks
- Supports any combination of input frequency and output frequencies
- Simple point-and-click configuration: www.silabs.com/ClockBuilder
- Generates a custom part number for each application-specific configuration
- No minimum order quantity restrictions
- Samples (2 pcs) and production orders of any part number available directly from the website
The Si5355/56 is complimented nicely by the Si5xx XO/VCXOs, the Si5338 any-rate, any-output clock generator and the Si5315/19/26/68 any-rate precision clocks. The Si5355/56 provide processor, memory and system interface clocking in lower end applications, and provide control plane (FPGA, processor) clocking in higher performance applications.