74HCT9046AN Philips, 74HCT9046AN Datasheet - Page 12

• Manufacturer Part Number: 74HCT9046AN
• Description: PLL with bandgap controlled VCO
• Manufacturer: Philips

Philips Semiconductors
LOOP FILTER COMPONENT SELECTION
1999 Jan 11
PLL with bandgap controlled VCO
a.
b. Amplitude characteristic:
c. Pole zero diagram.
a.
b. Amplitude characteristic:
c. Pole zero diagram.
A = DC gain limit, due to leakage.
1
1
2
=
=
=
R
------ -
R
------ -
R4 C2
17
17
R b
R b
I P
17
I P
17
b
b
C2
C2
=
=
R3' C2
R3' C2
INPUT
INPUT
F
F
j
j
C2
R4
C2
=
a.
a.
=
I P
I P
---------------------------- -
1 A
---------------------------- -
1 A
1
+
+
1
Fig.12 Simple loop filter for PC2 without damping.
+
j
j
Fig.13 Simple loop filter for PC2 with damping.
OUTPUT
OUTPUT
j
2
1
1
---------- -
j
1
1
F
F
j ( )
j ( )
A
1/
A
m
A
1
1/
12
A
1
b.
b.
1 /
2
1/
O
74HCT9046A
2
Product specification
MBD045 - 1
1/
c.
c.
A
MBD044 - 1
1
1/
A
1