May 9, 2005 #21 A amarnath Advanced Member level 1 Joined Apr 24, 2003 Messages 402 Helped 26 Reputation 52 Reaction score 7 Trophy points 1,298 Activity points 3,141 the ripple is caused due to the up and down pulses generated by the pfd even after the pll has acquired lock.so the cause of your problem is the pfd. regards amarnath
the ripple is caused due to the up and down pulses generated by the pfd even after the pll has acquired lock.so the cause of your problem is the pfd. regards amarnath
May 10, 2005 #22 J jerryhuang Member level 1 Joined Feb 3, 2005 Messages 38 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,286 Activity points 357 2 amarnath the pfd works at 20Mhz,why the ripple frequence is 120Khz?
May 10, 2005 #23 A amarnath Advanced Member level 1 Joined Apr 24, 2003 Messages 402 Helped 26 Reputation 52 Reaction score 7 Trophy points 1,298 Activity points 3,141 dont worry about the frequency of the ripple,just worry about the amplitude of the ripple.i advise you to change the value of the loop filter capacitance and see the amplitude of the ripple. regards amarnath
dont worry about the frequency of the ripple,just worry about the amplitude of the ripple.i advise you to change the value of the loop filter capacitance and see the amplitude of the ripple. regards amarnath
May 11, 2005 #24 V vbhupendra Full Member level 4 Joined May 11, 2005 Messages 235 Helped 15 Reputation 30 Reaction score 10 Trophy points 1,298 Location GOA, INDIA Activity points 3,219 you can use eldo for eye diagram
May 12, 2005 #25 A amarnath Advanced Member level 1 Joined Apr 24, 2003 Messages 402 Helped 26 Reputation 52 Reaction score 7 Trophy points 1,298 Activity points 3,141 u can also do the same using the functions in the calculator of cadence ic. regards amarnath