Programmable MGT RC21008A REF Clocks

VEK280 Evaluation Board User Guide (UG1612)

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1.1 English

[Figure 1, callout 36]

The VEK280 evaluation board has one I2C programmable RC21008A high-performance frequency synthesizer (U299) that provides excellent phase jitter on reference clocks. The output has been configured in various outputs. See the Clock Sources table in the Clock Generation section for more details.

At power-up, this clock defaults to an output frequency of 200 MHz for the LPDDR4, 100 MHz for the transceivers attached to the FMC+, 156.25 MHz for the transceivers attached to the zSFP+, and 25 MHz for the onboard Ethernet. User applications or the system controller can change the output frequency within the range of 0.001 MHz to 650 MHz through the I2C bus interface. Power cycling the VEK280 evaluation board reverts this user clock to the default frequencies listed previously.

  • Programmable frequency synthesizer: Renesas RC21008A097#BB0
  • 0.001 MHz-650 MHz range, 156.25 MHz default
  • I2C address 0x09
  • LVDS differential output