cxa3516r Sony Electronics, cxa3516r Datasheet - Page 61

• Manufacturer Part Number: cxa3516r
• Description: 3-channel 8-bit 165msps A/d Converter Amplifier Pll
• Manufacturer: Sony Electronics

Here, n and are as follows.
A capacitor C2 is added to the actual loop filter.
This added capacitor C2 is used to reduce the R noise, and a value of around 1/10 to 1/1000 of C1 should be
selected as necessary.
Current input type active filter with added capacitor C2
The filter transmittance is as follows.
Here, assuming C2 = C1/100, then:
n characteristic angular frequency:
The oscillatory angular frequency when PLL oscillation is assumed to have been maintained by the loop filter
and individual loop gains is called the characteristic angular frequency: n.
This is the PLL transient response characteristic, and serves as a measure of the PLL stability. It is
determined by the loop gain and the loop filter.
damping factor:
F (S) =
2
=
=
=
101
101
i
i
=
C1 · C1/100 · R
1
1
1
2
C1 + C1/100
S ((C1 + C2) + C1 · C2 · R · S)
S (C1 + C2) (1 + 2 · S)
= C1 · R
=
C1 · R
C1 · C2 · R
1
C1
C1 + C2
–A
C2
1 + 1 · S
1 + C1 · R · S
R
–Vo
–1
Vo
................... (3)
– 61 –
The Bode diagram for formula (3) is as follows.
–90
0
–45deg
log
log
1
1
1
2
CXA3516R