usuikazkou
Junior Member level 2
Hi guys,
I tried to reproduce a 5Ghz clock and data recovery circuit from a IEEE paper,
when I design v/i converter I found that in DC simulation the result is fine but in tran simulation have some problems. I wonder is this normal or not?
schematic of v/i converter:
M5 provides 500u A current, M0 and M1 steering the current. d1/u1 switching with 5 Ghz frequency.
dc simulation seems to be fine
something unexpected in my trans simulation
when d1 is high, m0 have ~500u current that is normal, but m12 has only 209u current which it should be same as m0, I found that the issues is the M14 gate has ~150u current leakage .
alternative question, what is the difference of v/i converter and charge pump? textbook doesn't discuss about this.
or perhaps v/i converter doesn't expect such high switching speed? or I misunderstanding the function of v/i converter(expectation from PLL/CDR's v/i converter)?
I am new to High speed circuit and PLL/CDR.
I will provide more detail as I can if my question still unclear.
Thank you.
I tried to reproduce a 5Ghz clock and data recovery circuit from a IEEE paper,
when I design v/i converter I found that in DC simulation the result is fine but in tran simulation have some problems. I wonder is this normal or not?
schematic of v/i converter:
M5 provides 500u A current, M0 and M1 steering the current. d1/u1 switching with 5 Ghz frequency.
dc simulation seems to be fine
something unexpected in my trans simulation
when d1 is high, m0 have ~500u current that is normal, but m12 has only 209u current which it should be same as m0, I found that the issues is the M14 gate has ~150u current leakage .
alternative question, what is the difference of v/i converter and charge pump? textbook doesn't discuss about this.
or perhaps v/i converter doesn't expect such high switching speed? or I misunderstanding the function of v/i converter(expectation from PLL/CDR's v/i converter)?
I am new to High speed circuit and PLL/CDR.
I will provide more detail as I can if my question still unclear.
Thank you.