If I have the ref clock running at 27MHz, what is the frequency range of the incoming data clock that this device will lock to? The only spec the data sheet gives me is that the ref clock must be +/-100 ppm.
Thanks, in advance.
Hi Scott,
The parallel clock rate corresponding to the serial data can be found by dividing the serial data rate by 12. This rate should be within 200 ppm of the deserializer's reference clock rate. In your case, the nominal serial data rate should be 324 Mbps. If your reference clock is specified to within +/- 100 ppm, then the data rate should be specified to within +/- 100 ppm as well. If your reference clock spec is tighter (e.g., +/- 50 ppm), then the serial data spec can be relaxed (e.g., to +/- 150 ppm) and vice-versa.
Regards,Max RobertsonAnalog Applications EngineerTexas Instrumentsm-robertson@ti.com
If you are having difficulty meeting the timing requirements for this device you could consider using the DS92LV1224. The DS92LV1224 allows for +/-5% tolerance on the reference clock compared to the +/-100ppm of the SN65LV1224.
Mike Wolfe
DPS APPS / SVA