Clock generators
EMI reduction and non-EMI reduction clock generators for automotive, industrial, consumer, and networking applications
Infineon has a broad portfolio of clock generators with frequency support of 700 MHz and RMS phase jitter of less than 0.7 ps. They support a host of value-added features such as VCXO, spread-spectrum, and output phase alignment, along with supporting reference clocks for popular interface standards such as PCIe 1.0/2.0/3.0, 10 GbE, SATA 1.0/2.0 and USB 1.0/2.0/3.0. We have commercial, industrial, and automotive-grade products.
- VCXO functionality
- Field- and factory-programmable
- Glitch-free frequency switching
- PLL cascading
- AEC-Q100 qualified
- Voltage-controlled frequency synthesis
Infineon's family of clock generators
Clock generators can be broadly classified into two categories:
- EMI reduction (spread-spectrum capability)
- Non-EMI reduction.
Target applications for these devices include automotive, industrial, consumer, and networking.
EMI can cause an increase in ringing, overshoot, and undershoot and make the system more susceptible to other sources of interference. Using filtering techniques or ferrite beads to reduce EMI issues may be minimally effective for the complete system. An effective method is spread-spectrum clock-generation, in which the system clock is modulated over a narrow band of modulating frequency, which results in spreading the clock over a broader band. The CY254x family provides efficient EMI reduction using spread-spectrum clock generation.
Reduced EMI using Infineon's clock generators
Spread-spectrum capability is the feature that sets CY25701 apart from most other crystal oscillators. When an oscillator is used to provide the system clock, a majority of the data and clock signals throughout the system switch at some multiple of the system clock rate. This causes significant EMI at odd harmonics of the system frequency. With the ability to modulate the system clock frequency, the peak energy of the fundamental frequency and odd harmonics can be dispersed over a wider frequency range. Thus, the peak energy in those frequency bands is reduced significantly. A spread-spectrum clock suppresses EMI particularly during EMC compliance testing and saves a lot of time and redesign effort.
