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Electrical Characteristics
Characteristic Sym Notes Minimum Typical Maximum Units
Center Frequency, +25 °C Absolute Frequency fC2,3,4,5 314.950 315.050 MHz
Tolerance from 315.0 MHz ∆fC±50 kHz
Insertion Loss IL 2,5,6 1.5 2.2 dB
Quality Factor Unloaded Q QU5,6,7 8000
50 Ω Loaded Q QL1300
Temperature Stability Turnover Temperature TO6,7,8 10 25 40 °C
Turnover Frequency fOfC
Frequency Temperature Coefficient FTC 0.032 ppm/°C2
Frequency Aging Absolute Value during the First Year |fA|1≤10 ppm/yr
DC Insulation Resistance between Any Two Terminals 5 1.0 MΩ
RF Equivalent RLC Model Motional Resistance RM5, 7, 9 19.4 Ω
Motional Inductance LM78.4 µH
Motional Capacitance CM3.3 fF
Shunt Static Capacitance CO5, 6, 9 4.1 pF
Test Fixture Shunt Inductance LTEST 2, 7 64.2 nH
Lid Symbolization (in addition to Lot and/or Date Codes) 742 // YWWS
• Ideal for 315.0 MHz Transmitters
• Very Low Series Resistance
• Quartz Stability
• Surface-mount Ceramic Case
• Complies with Directive 2002/95/EC (RoHS)
The RO3073A-1 is a true one-port, surface-acoustic-wave (SAW) resonator in a surface-mount, ceramic case.
It provides reliable, fundamental- mode, quartz frequency stabilization of fix ed-frequency transmitters
operating at 315.0 MHz. This SAW is designed specifically for remote control and wireless security
transmitters.
Absolute Maximum Ratings
Rating Value Units
CW RF Power Dissipation (See: Typical Test Circuit) +0 dBm
DC Voltage Between Terminals (Observe ESD Precautions) ±30 VDC
Case Temperature -40 to +85 °C
Soldering Temperature (10 seconds / 5 cycles maximum) 260 °C
315.0 MHz
SAW
Resonator
RO3073A-1
CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.
Notes:
1. Frequency agin g is the chang e in fC with time an d is specif ied at +65 °C or
less. Aging may exceed the specification for prolonged temper atures
above +65 °C. Typically, aging is greatest the first year after manufacture,
decreasing in subsequent years.
2. The cen ter frequency, fC, is measured at the minimum insertion los s point,
ILMIN, wi th the resonator in the 50 Ω test system (VSWR ≤ 1.2:1) . Th e
shunt inductance, LTEST, is tuned for parallel resonance with CO at fC.
Typi cally, fOSCILLATOR or fTRANSMITTER is approx imately equal to the
resonator fC.
3. One or more of the following United States patents apply: 4,454,488 and
4,616,197.
4. Typically, equipment utilizing this device requires emissions testing and
government approval, which is the responsibility of the equipment
manufacturer.
5. Unless noted otherwise, case temperat ure TC= +25 ± 2 °C.
6. The design, manufacturing process, and specifications of this device are
subject to change without notice.
7. Derived mat hematically from one or more of the following directly
measured parameters: fC, IL, 3 dB bandwidth, fC versus TC, and CO.
8. Turnover temperature, TO, is the temperature of maximum (or turnover)
frequenc y, fO. The n ominal f requency at any ca se tempera ture, T C, may be
calculated from: f = fO[1 - FTC (TO-TC)2]. Typical ly oscillator T O is
approximately equal to the specified resonator TO.
9. This equiv alent RLC model approximates resonator performance near the
resonan t frequen cy and is provided for refer ence o nly. The capaci tanc e CO
is the static (nonmotional) capacitance between the two terminals
measured at low frequenc y (10 MHz) with a capacitance meter. The
measuremen t includes p arasitic cap acitanc e with "NC” pads unconne cted.
Case par asitic capacitance is approximately 0.05 pF. Transducer p arallel
capacitance can by calculated as: CP≈CO-0.05pF.
10. Tape and Reel standard per ANSI / EIA 481.
SM5035-4
Pb
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© 2008-2011 by RF Monolithics, Inc. RO3073A-1 6/29/11
Electrical Connections
The SAW resonator is bidirectional and may be
installed with either orientation. T he two terminals
are interchangeable and unnumbered. The callout
NC indicates no internal connection. The NC pads
assist with mechanical positioning and stability.
External grounding of the NC pads is
recommended to help reduce parasitic
capacitance in the circuit.
Typical Test Circuit
The test circuit inductor , LTEST, is tuned to resonate with the static
capacitance, CO, a t FC.
Typical Application Circuits
Equivalent Model
Temperature Characteristics
The curve shown on the right
accounts for resonator
contribution only and does not
include LC component
temperature contributions.
Case
Terminal
Terminal
Case Ground
Case Ground
ELECTRICAL TEST
From 50 Ω
Network Analyzer To 50 Ω
Networ k A nalyzer
50 Ω Source
at FCREFLECTED
INCIDENT
P
P
Low-Loss
Matching
Network to
50 Ω
Terminal
Terminal
NC NC
POWE R T EST
CW RF Power Dissipation = INCIDENT - REFLECTED
P P
C1
C2
L1
(Antenna)
+9VDC
47
RF Bypass
Modulation
Input
Typical Low-Power Transmitter Application
RO3XXXA
Bottom View 470
200kΩ
C1
C2
L1
Output
+VDC
RF Bypass
+VDC
Typical Local Oscillator Applications
RO3XXXA
Bottom View
Dimensions Millimeters Inches
Min Nom Max Min Nom Max
A 4.87 5.00 5.13 0.191 0.196 0.201
B 3.37 3.50 3.63 0.132 0.137 0.142
C 1.45 1.53 1.60 0.057 0.060 0.062
D 1.35 1.43 1.50 0.040 0.057 0.059
E 0.67 0.80 0.93 0.026 0.031 0.036
F 0.37 0.50 0.63 0.014 0.019 0.024
G 1.07 1.20 1.33 0.042 0.047 0.052
H - 1.04 - - 0.041 -
I - 1.46 - - 0.058 -
J - 0.50 - - 0.019 -
K - 1.05 - - 0.041 -
L - 1.44 - - 0.057 -
M - 0.71 - - 0.028 -
0.05 pF*
0.05 pF
Cp
Co+
=
*Case Parasitics
Cp
Rm
Lm C m
-80 -60 -40 -20 0 +20 +40 +60
0
-50
-
100
-
150
+80
-
200
0
-50
-100
-150
-200
f
C
= f
O
, T
C
= T
O
∆
T = T
C
- T
O
( °C )
(f-foo
)/f(ppm)
A
B C
D
E ( 3 x )
F ( 4 x )
G ( 1 x )
T o p V i e w S i d e V i e w B o t t o m V i e w
1
2
3
4
H
I
H H
J
J
K
L
MM
PCB Land Pattern
Top View
