OP4008B Datasheet, PDF (2/6 Pages) RF Monolithics, Inc – Quartz SAW Stabilized and Filtered “Diff Sine” Technology

BLOCK DIAGRAM
OP4008B
VCC
669.8
669.7
Q
_
V _tune
Q
SAW Oscillator Buffer Amplifier
669.6
669.5
MHz _669.4
669.3
669.2
OP4008B Tuning
669.1
669
0
2 Tune Volts
4
6
The OP4008B will tune from 0 to 5 volts as shown in the adjacent
plot. For normal use in a PLL, the tuning voltage will not change
much from the nominal operating point. The operating point is
determined by: (1) the temperature of the OP4008B case, (2) the
reference frequency from the PLL, and (3) the internal
characteristics of the key components used in the OP4008B part.
Although the nominal operating point may be different from part to
part by up to 1 volt, the locked operation of the part in a PLL will not
tune more than 0.5 volts, allowing good linearity over the operating
range.
REF
holdover
Xtal
Typical PLL
+Vcc
Loop Filter
Tune
Q
Q
OP4008B
.. _N
RFM's OPB-series Voltage Controlled SAW Clocks are designed for use in Phase Lock Loops (PLL’s) for optical timing applications. PLL operating
parameters such as loop bandwidth are typically determined by optical timing requirements, and noise reduction demands in a given system. The phase
noise in the OP4008B Clock is good enough to allow the loop bandwidth to be set at 100 Hz or less. Optical timing systems containing multiple or cascaded
timing loops have additional considerations that apply. For example, jitter peaking is often determined by VCO linearity.
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