Hi
Your op-amp noise is either 1/f sloped or flat spectrally. The EFC transfer
function has
a 1/f slope due to FM to PM conversion (you modulate FM and you look at PM).
The noise out
of the amp will roll off pretty fast.
The gotcha is that your oscillator noise may also be rolling of pretty
Hi,
The PLL acts like a combined lowpass and highpass filter.
Noise in the loop is high-pass filtered, thus, the further down from the
loop bandwidth, the better suppression of the noise.
Noise on the reference input is low-pass filtered, so that it passes
through DC and a bit more, but high
Thank you Bob.
I was thinking of the contribution outside the loop, as for most part my
PLL loops are around 1Hz and resolving closer than 10Hz isn't easy with a
analyzer that stops at 10Hz.
I guess what I'm asking is: should I take any care in the unity gain
buffers or would any normal garden
Hi
Ok, let’s back up a bit:
There are two basic regions when measuring a phase locked oscillator. You
can be “inside” the loop bandwidth or “outside”. Yes it’s a bit more complex
than that, but go with the idea for now. Inside the bandwidth, everything about
the PLL can / may matter. It can
Hi.
When measuring Phase Noise using PLL, what noise would be contribuded from
the PLL into the amplifier?
Lets say we disconnect the control voltage from the oscillator, shouldn't
the input stage of the PLL contribute some, altough miniscule part to the
total noise seen?
Would this noise be
