M672 Datasheet, PDF (1/4 Pages) Integrated Circuit Systems – VCSO WITH SELECTABLE OUTPUT FREQUENCY DIVIDER

Integrated
Circuit
Systems, Inc.
Preliminary Information
M672
VCSO WITH SELECTABLE OUTPUT FREQUENCY DIVIDER
GENERAL DESCRIPTION
PIN ASSIGNMENT (5 x 7.5mm SMT)
The M672 is a Voltage Controlled SAW Oscillator
(VCSO) with a selectable output frequency
divider. The output frequency can be
pin-selected to be either the VCSO
fundamental frequency (Fvcso) or a
fraction of Fvcso (¹/8, ¹/4, or ¹/2 depending
on frequency and order code). Available center
fundamental frequencies for the VCSO are between
125 and 700MHz. Divided Fvcso frequencies are in the
60 to 175MHz range. The M672 SAW (surface acoustic
wave) VCO is a high Q frequency source for low-jitter
clock generation. It is well suited for phase-locked loop
implementations, clock and data recovery circuits, and
other timing applications in telecom and optical fiber
networking systems (e.g., SONET/SDH).
FEATURES
◆ Selectable divider chooses one of two output
frequencies; the Fvcso or its divided output frequency
◆ Low phase jitter 0.2ps rms typical (50kHz to 80MHz)
◆ Differential 3.3V LVPECL output
◆ Single 3.3V power supply
◆ Small 5 x 7.5mm SMT (surface mount) package
M⁶⁷7²2
(Top View)
Figure 1: Pin Assignment
Sample of Available Output Frequencies
VCSO Center Corresponding
Fundamental
P Divider¹
Frequency¹ (MHz)
Output Frequency
Selections (MHz)
622.0800
4
622.0800, 155.5200
622.0800
8
622.0800, 77.7600
311.0400
2
311.0400, 155.5200
155.5200
2
155.5200, 77.7600
Table 1: Sample of Available Output Frequencies
Note 1: Specify VCSO center frequency and valid
corresponding P divider value at time of order.
See Ordering Information on pg. 4.
BLOCK DIAGRAM
M672
VIN
P_SEL
SAW Delay Line
Phase
Shifter
P Divider
P=1 (P_SEL=0)
or d (P_SEL=1) *
FOUT
nFOUT
Figure 2: Block Diagram
* The P divider value d (4, 8, or 2) is specified as part
of the order number (format is M672-d-xx).
M672 Datasheet Rev 0.2
Revised 07Apr2004
M672 VCSO with Selectable Output Frequency Divider
Integrated Circuit Systems, Inc. ● Communications Modules ● www.icst.com ● tel [phone]