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Design >> Analog Design >> CPPLL unit
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Message started by newic on Jul 12^th, 2010, 3:27am

Title: CPPLL unit
Post by newic on Jul 12^th, 2010, 3:27am

I want to confirm the units of each component for a CPPLL

input=phi_error (rad)
Phase detector + CP : Icp/2pi (A/rad)
LPF: impedance (ohm)
VCO: 2pi*Kvco/s (rad/V)

output of VCO clk: rad*(A/rad)*(ohm)*(rad/V)= rad

is it correct?
should the VCO gain be Hz/V or rad/V?

Title: Re: CPPLL unit
Post by Mayank on Jul 13^th, 2010, 1:43am

2*pi*f = ω(angular velocity) where f is in Hz & ω is in rad/s.

Hence 2*pi* x Hz/V = y rad/V.

Units of Kvco are Hz/V & hence, 2*pi*Kvco translates it to rad/sec/V.

Integrating this i.e. multiplying by (1/s) in Freq. Domain yields rad/V.

--M