LMK04828

Hello David,

There are two ways to get high frequency signals out of the LMK04828:

1. Use the bypass mode to directly drive DCLKoutX with the clock distribution frequency. There is no digital or analog delay correction in bypass mode, so the skew between the outputs must be calibrated out externally. This approach uses two different DCLKoutX outputs, for instance DCLKout4 and DCLKout6. 

Use a divide-by-1 and enable the Divider+DCC+HS in DCLKoutX_MUX, then set SDCLKoutY_MUX to use device clock output. The two outputs will draw from the same source and phase skew between them should remain consistent between power cycles. Same X_Y pair skew in the same output format should be smaller than ±25ps.

1. Alternately, two different DCLKoutX outputs could be configured in divide-by-1 and analog delay + divider path, with half-step and duty cycle correction enabled for the analog delay path using DCLKoutX_ADLY_MUX. After synchronizing both of the clocks, the device clock analog delays could be used to further fine-tune delay variation. Same format but different DCLKoutX is typically ±50ps skew in the datasheet, so analog delay tuning may be required for optimal alignment.

Make sure to use the same output format and termination for both outputs.

Regards,