mc145170-2 Freescale Semiconductor, Inc, mc145170-2 Datasheet - Page 21

• Manufacturer Part Number: mc145170-2
• Description: Pll Frequency Synthesizer With Serial Interface
• Manufacturer: Freescale Semiconductor, Inc

Freescale Semiconductor
NOTES:
1.
2.
3.
4.
5.
The φ
Low-Pass Filter Design page for additional information. The φ
Therefore, the user should be careful not to exceed the common mode input range of the op amp used
inthe combiner/loop filter.
capacitors.
required for the VCO. Also, the VCO frequency divided by f
of the N counter.
For optimum performance, bypass the V
The R counter is programmed for a divide value = OSC
May be an R-C low-pass filter.
May be a bipolar transistor.
MCU
V+
R
and φ
V
outputs are fed to an external combiner/loop filter. See the Phase-Locked Loop —
Optional
Figure 24. Example Application
MC145170-2 Technical Data, Rev. 5
VHF VCO
Buffer
Threshold
Detector
Optional
(Note 5)
VHF Output
DD
1
2
3
4
5
6
7
8
pin to V
OSC
OSC
REF
f
D
ENB
CLK
D
in
in
out
Low-pass Filter
in
out
SS
(GND) with one or more low-inductance
in
/f
R
Integrator
(Note 4)
. Typically, f
R
= N, wher e N is the divide value
R
PD
and φ
V
V
LD
φ
φ
DD
out
SS
f
f
R
R
V
V
16
15
14
13
12
11
10
9
V
R
outputs swing rail-to-rail.
is the tuning resolution
V+
Loop Error Signals
Optional
(Note 1)
Design Considerations
21