keikei wrote on Jan 20th, 2008, 8:24pm:I had a question about Dr. Maneatis' paper "Low-Jitter Process-Independent DLL and PLL Based on Self-Biased Techniques" published in JSSCC 1996.
According to Fig.2, the bias voltages VBP and VBN are generated from the control voltage VCTRL. As VCTRL increases, VBP increases and VBN drops.
I think the VCO oscillating frequency should lower when VCTRL increases, Since VBN is used to bias the tail current sources in the buffer stages.
However Fig. 10 shows that the VCO runs faster when VCTRL increases.
Can anyone tell me what the problem is?
hi
actually, VCTRL is refer to vdd, so VCTRL= vdd- VCTRL'