Product Data Sheet
V-Type
Voltage Controlled Crystal Oscillator (VCXO)
Features
• Output Frequencies to 77.760 MHz
• 5.0 or 3.3 volt operation
• Tri-State Output
• Jitter Performance <6 ps rms (freq >12MHz)
• VCXO with SwitchableTTL/CMOS Output
• Robust 6 contact Leadless Ceramic Chip Carrier
• 7.49 x 5.08 x 1.8 mm Surface Mount Device
• Absolute Pull Range Performance to 100 ppm
• Commercial and Industrial Temperature Range
• EIA Compatible Tape and Reel Packaging
Applications
•
•
•
•
xDSL Customer Premise Equipment (CPE)
Cable Modems
HFC Subscriber Equipmemt
ATM/SONET/SDH applications
Description
The VI V-Type Voltage Controlled Crystal
Oscillator (VCXO) is a quartz-stabilized
square-wave generator with selectable TTL or
CMOS output. The device is hermetically
sealed in a leadless ceramic chip carrier with
6 contact pads.
The V-Type’s ultra small footprint and low pro-
file make it ideally suited to applications where
space is limited or where backside assembly
is required.
V-Type Voltage Controlled Crystal Oscillator (VCXO)
Pin Information
Table 1.
Pin #
1
2
2
3
4
5
2
6
Symbol
Vc
TTL/CMOS
1
GND
Output
Tri-state
V
DD
Name/Function
Control Voltage.
TTL logic low for CMOS optimized symmetry
TTL logic high or no connection for TTL optimized symmetry.
Case/circuit ground.
Output waveform.
TTL logic low diables output.
TTL logic high or no connection enables output waveform.
Supply Voltage, 5 V ±10%, or 3.3V ±10%
than 12 MHz, this option is not provided as the waveform tran-
sition times are small compared to the period. Hence, for fo
<12 MHz this pin should be grounded for electrical isolation.
2. Alternate Pin Configuration for Tri-state Control on Pin 2
and TTL/CMOS on pin 5. Alternate Configuration is indicated
by last letter of part code “D” for TriState Pin 2 and TTL/CMOS
on pin 5.
1. This silicon oscillator is fabricated in CMOS technology and
its output waveform will swing between ground and VDD for
all but the highest frequency applications. To account for the
difference in switching thresholds between TTL logic (1.40 V)
and CMOS logic (VDD/2), the TTL/CMOS lead modifies the
“on time” of the oscillator for maximum symmetry about the
TTL or CMOS logic threshold. TTL logic low provides wave-
form symmetry for CMOS. TTL logic high or no connection pro-
vides waveform symmetry for TTL. At output frequencies less
Table 2. Performance Specifications
Parameter
Supply Voltage’ (5V or 3.3V)
Supply Current (Frequency Dependent)
OutputVoltage Levels (V
DD
= 4.5V):
Output Logic High
2
Output Logic Low
2
Transition Times
2
:
Rise Time
Fall Time
Symmetry or Duty Cycle
3
Nominal Output Frequency (see ordering info)
Control Voltage (5v), test conditions for APR
Control Voltage (3.3v), test conditions for APR
Control Voltage
Absolute Pull Range (see ordering info)
Leakage Current of Control Input
Control Voltage Bandwidth (-3 dB,V
C
=2.50V)
Symbol
V
DD
I
DD
V
OH
V
OL
t
R
t
F
SYM
fo
Vc
Vc
Vc
APR
Ivcxo
BW
Min
0.9*V
DD
Max
1.1*V
DD
Unit
V
mA
V
V
ns
ns
%
MHz
V
V
V
uA
kHz
See Figures 7,8
0.8*V
DD
-
-
0.1*V
DD
5
5
See figure 3, 4
1.024
0.5
0.3
0
±20 to ±100
-1.0
10
1.0
-
77.760
4.5
3.0
V
DD
1 A 0.1 uF low frequency tantalum bypass capacitor in parallel with a
0.01 uF high-frequency ceramic capacitor is recommended.
2 Figure 1 defines these parameters. Figure 2 illustrates the equiva-
lent five-gate MTTL load and operating conditions under which
these parameters are specified.
3 Symmetry is defined as (ON TIME/PERIOD), with VS = 1.4 V for
TTL or VS = 2.5 V for CMOS. per Figure 1.
Vectron International • 166 Glover Avenue, Norwalk, CT 06856 • Tel: 1-88-VECTRON-1 • Fax: 1-888-FAX-VECTRON
2
V-Type Voltage Controlled Crystal Oscillator (VCXO)
Table 3: Typical Single-Side Band Phase Noise Data (dBc/Hz)
Offset From Carrier
10 Hz
100 Hz
1 KHz
10 KHz
100 KHz
6.176MHz
-80
-109
-134
-147
-152
12.288MHz
-70
-100
-129
-145
-152
VCXO Center Frequency
19.440MHz 32.768MHz 39.3216MHz
-70
-68
-63
-100
-98
-93
-129
-125
-122
-145
-147
-144
-152
-152
-151
44.736MHz
-63
-93
-122
-144
-151
51.840MHz
-63
-93
-122
-144
-151
Electrical Specifications
Figure 1. Output Waveform
*Includes probe
and test jig
capacitance
Figure 2. Output Test Conditions
(T
amb
= 25 ±5°C)
Characteristic Curves
Vectron International • 166 Glover Avenue, Norwalk, CT 06856 • Tel: 1-88-VECTRON-1 • Fax: 1-888-FAX-VECTRON
3
V-Type Voltage Controlled Crystal Oscillator (VCXO)
Characteristic Curves
(continued)
Vectron International • 166 Glover Avenue, Norwalk, CT 06856 • Tel: 1-88-VECTRON-1 • Fax: 1-888-FAX-VECTRON
4
V-Type Voltage Controlled Crystal Oscillator (VCXO)
Table 4. Absolute Pull Range (APR)
Parameter
Absolute Frequency Pull Range:
Control Voltage, Vc = 0.50V for 5V
Control Voltage, Vc = 4.50V for 5V
Control Voltage, Vc = 0.30V for 3.3V
Control Voltage, Vc = 3.00V for 3.3V
Symbol
APR
-
-
-
-
Min
-
-APR
+APR
-APR
+APR
Max
-
-
-
-
-
Unit
ppm from f
o
ppm from f
o
ppm from f
o
ppm from f
o
ppm from f
o
Absolute pull range (APR) is specified by the fourth character of the
product code (seeTable 5). The APR is the minimum guaranteed fre-
quency shift from fo over variations in temperature, aging, power sup-
ply, and load. Both frequency and environment limit the specified APR.
With Vc between 0.5 V and 4.5 V, total pull range for the V-Type
VCXO is typically between 200 ppm and 400 ppm. A 50 ppm APR
V-Type VCXO will fully track a 50 ppm source oscillator or other 50
ppm reference under all specified environmental conditions.
Table 5. Mechanical and Environmental Compliance
Parameter
Mechanical Shock
Mechanical Vibration
Lead Solderability
Gross Leak
Fine Leak
StorageTemperature
Conditions
MIL-STD-883C, 2002.3 B
MIL-STD-883C, 2007.1 A
MIL-STD-883C, 2003.5
MIL-STD-883C, 1014.7
MIL-STD-883C, 1014.7
-55 °C to 125 °C
Oscillator Aging
Quartz stabilized oscillators typically exhibit a change in out-
put frequency with age. The major factors that contribute to
this change are variations in the mechanical stress applied
to the quartz crystal and mass-loading of foreign material
upon the quartz crystal.
As the oscillator ages, relaxation of the crystal’s mounting
stress can lead to frequency variation. In some oscillator
products, additional variations may be brought about by the
transfer of external environmental stress through the device
package and crystal mounting arrangement. VI has mini-
mized these two effects through the use of a state-of-the-art
miniature AT-Cut rectangular resonator. This crystal allows a
mounting arrangement that results in minimal relaxation and
very little environmental stress transfer.
Mass-loading of the quartz resonator, which generally drives
the frequency lower, is a result of outgassing of materials
within a hermetic package or contamination from external
materials in a less than hermetic device. In general, higher fre-
quency resonators are more susceptible to this aging mecha-
nism. VI has minimized the V-Type’s sensitivity to these effects
by ensuring the hermetic integrity of the package design and
by minimizing the parts count in the device. By using monolith-
ic IC technology, the component count is reduced and the
amount of material likely to outgas is minimized.
Under normal operating conditions with an operating tem-
perature of 40°C, the V-Type VCXO will typically exhibit
2ppm aging in its first year of operation.The device is then
expected to exhibit 1ppm aging the following year and will
continue a logarithmic decline for each year there after.
Vectron International • 166 Glover Avenue, Norwalk, CT 06856 • Tel: 1-88-VECTRON-1 • Fax: 1-888-FAX-VECTRON
5
汽车电子
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
