
RF Monolithics, Inc.
RFM Europe
1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
Phone: (972) 233-2903
Phone: 44 1963 251383
Fax: (972) 387-9148
Fax: 44 1963 251510
E-mail: info@rfm.com
http://www.rfm.com
SC3018B-111799
Page 1 of 2
Case Temperature (Powered or Storage)
CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.
NOTES:
Unless otherwise noted, all specifications include any combination of load
VSWR, VCC, and TA. In addition, Q and Q are terminated into 50
loads to
ground. (See: Typical Test Circuit.)
One or more of the following United States patents apply: 4,616,197; 4,670,681;
4,760,352.
The design, manufacturing process, and specifications of this device are subject
to change without notice.
Only under the nominal conditions of 50
load impedance with VSWR
≤
1.2 and
nominal power supply voltage.
Symmetry is defined as the pulse width (in percent of total period) measured at
the 50% points of Q or Q. (See: Timing Definitions.)
Electrical Characteristics
Characteristic
Absolute Frequency
Tolerance from 250.00 MHz
Voltage into 50
(VSWR
≤
1.2)
Operating Load VSWR
Symmetry
Harmonic Spurious
Nonharmonic Spurious
No Noise on V
CC
200 mV
P-P
from 1 MHz to f
O
on
Amplitude into 50
Sym
f
O
f
O
V
O
Notes
Minimum
249.950
Typical
Maximum
250.050
±200
1.1
2:1
51
-30
-60
30
35
75
Units
MHz
ppm
Output Frequency
1, 2
Q and Q Output
1, 3
0.60
V
P-P
3, 4, 5
49
%
dBc
dBc
ps
P-P
ps
P-P
mV
P-P
K
V
V
mA
mA
ms
VDC
mA
°C
3, 4, 6
Q and Q Period Jitter
3, 4, 6, 7
3, 4, 7, 8
3, 9
3
15
Output (Disabled)
Output DC Resistance (between Q & Q)
ENABLE (Terminal 14)
50
Input HIGH Voltage
Input LOW Voltage
Input HIGH Current
Input LOW Current
Propagation Delay
Operating Voltage
Operating Current
V
IH
V
IL
I
IH
I
IL
t
PD
V
CC
I
CC
T
A
3, 9
V
CC
-0.1
0.0
V
CC
V
CC
+0.1
0.20
5
-1
1
+3.47
40
+70
3
DC Power Supply
1, 3
+3.13
+3.30
20
Operating Ambient Temperature
Lid Symbolization (YY = Year, WW = Week)
1, 3
0
RFM SC3018B 250.00 MHz YYWW
Quartz SAW Frequency Stability
Fundamental Fixed Frequency
Very Low Jitter and Power Consumption
Rugged, Miniature, Surface-Mount Case
Low-Voltage Power Supply (3.3 VDC)
This digital clock is designed for use with high-speed CPUs and communication equipment. Fundamental-
mode oscillation is made possible by surface-acoustic-wave (SAW) technology. The design results in low jit-
ter, compact size, and low power consumption. Differential outputs provide a sine wave that is capable of
driving 50
loads.
Rating
Value
0 to +4.0
0 to +4.0
-40 to +85
Units
VDC
VDC
°C
Power Supply Voltage (V
CC
at Terminal 1)
Input Voltage (ENABLE at Terminal 8)
250.0 MHz
Differential
Sine-Wave
Clock
SC3018B
SMC-8 Case
1.
2.
3.
4.
5.
6.
Jitter and other spurious outputs induced by externally generated electrical noise
on V
CC
or mechanical vibration are not included. Dedicated external voltage
regulation and careful PCB layout are recommended for optimum performance.
Applies to period jitter of Q and Q. Measurements are made with the Tektronix
CSA803 signal analyzer with at least 1000 samples.
Period jitter measured with a 200 mV
P-P
sine wave swept from 1 MHz to one-half
of f
O
at the V
CC
power supply terminal.
The outputs are enabled when Terminal 8 is at logic HIGH. Propagation delay is
defined as the time from the 50% point on the rising edge of ENABLE to the 90%
point on the rising edge of the output amplitude or as the fall time from the 50%
point to the 10% point. (SEE: Timing Definitions.)
7.
8.
9.