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To deal with large frequency offset such as spread-spectrum, often CDR is engaged in second order.
I'm wondering how second order makes frequency tracking range wider in general. I understand phase interpolation step size is also a factor of tracking range regardless of loop order...
As you might know, CEI-6G-LR standard does NOT specifically specify Rx input eye mask but it only defines 1200mVpp maximum.
Maybe I'm missing something but how do you define CEI-6G-LR input eye mask for your design? Is there any jitter tolerance spec defined in it?
Pls give me some help to solve my confusion.
In case a CDR has +/-2000ppm offset tracking ability, is this 2000ppm only on data or only on reference clock?
I think certain ppm from one data rate is much smaller than same ppm from reference clock, assuming some multiplication in Rx PLL.
I've been working on CDR basics study. CDR is supposed to b useful because clock can b embeded. In fact however, many SERDES rx uses external ref clock generated in tx.
I think that ext clk incorporated with phase interpolation may help to deserialize less jittery manner relatively...
Apparently there are so many kinds of known oscillator structure that does not expect LC-tank. I'd like to ask you what fully on-chip oscillator topology you think best around a few tens of MHz in terms of jitter/power/area/psrr. RC oscillator? or n-stage ring oscillator? and Why...
Hi guys here,
Cap-free or cap-less LDO also brings problem with start-up|power-up additionally to other trainsient deals discussed here. Does anyone have simillar problems ? and how was it solved? Stability and faster transient response were managable somehow but this start-up issue now bugs me...
I am very new to SKILL or ocean script . I have problems with following script. Firstly I created this ocean.ocn by ADE>Session>Save ocean script... Then added some lines to output data to file. However it ends up outputing error after successful simulation but I do not know...
how many stages are in vco?
Thank you for your comment and sorry for my word short, behind the simulation, I turned on Kvco boost switch in VCO and lowered Vcnt accordingly to realize same level of osc frequency. So, Kvco is really different with same swing.
I am thinking this...
I've been trying to downsize the volume of VCO noise at 3GHz use.
According to spectreRF (MMSIM7.0.1) pss+pnoise analysis for VCO only, higher Kvco gives same phase noise over entire offset.
But I believe higher Kvco should bring worse phase margin since noise sensitivity...