Infineon CY2XF24FLXIT

The CY2XF24 is a high-performance and high-frequency XO. It uses a Cypress-proprietary low-noise PLL to synthesize the frequency from an integrated crystal. The output frequency can be changed using the I2C bus serial interface, allowing easy frequency margin testing in applications. The CY2XF24 is a PLL-based high-performance clock generator. It uses an internal crystal oscillator as a reference, and outputs one differential LVPECL clock. It has an I2C bus serial interface, which is used to change the output frequency. The CY2XF24 comes configured for four different frequencies. At power-on, the four configurations are transparently loaded into an internal volatile memory which, in turn, controls the PLL. You can switch between the four frequencies through the I2C bus. You can also configure the CY2XF24 with new output frequencies by shifting new data into the internal memory. Frequency margining is a common application for this feature. One frequency is used for the standard operating mode of the device, while additional frequencies are available for margin testing, either during product development or in-system manufacturing test. The configuration for a particular frequency is stored in a 6-byte block of memory, known as a word. The CY2XF24 has four such words, labeled ‘Frequency Word 0’ through ‘Frequency Word 3’. An additional register byte contains a 2-bit field, which selects one of the four frequency words. By writing to this Select Byte, you can switch back and forth between the four programmed frequencies. The select byte can be configured to select any of the four frequency words at power on. When changing the output frequency, the frequency transition is not guaranteed to be smooth. There can be frequency excursions beyond the start frequency and the new frequency. Glitches and runt pulses are possible, and time must be allowed for the PLL to relock. If more than four frequencies are needed, the I2C Bus can be used to change any of the four frequency words. When writing frequency words through I2C, you should not change the currently selected word. Instead, write one of the three unselected words before changing the select byte to select that new word.

• Low jitter crystal oscillator (XO)
• Less than 1 ps typical root mean square (RMS) phase jitter
• Differential low-voltage positive emitter coupled logic (LVPECL) output
• Output frequency from 50 MHz to 690 MHz
• Frequency margining through I2C bus
• Factory-configured or field-programmable
• Integrated phase-locked loop (PLL)
• Pb-free package: 5.0×3.2 mm leadless chip carrier (LCC)
• Supply voltage: 3.3 V or 2.5 V
• Commercial and industrial temperature ranges