©2010-2014 by Murata Electronics N.A., Inc.
RO3120A (R) 4/18/14 Page 1 of 2 www.murata.com
RFM products are now
Murata products.
Characteristic Sym Notes Minimum Typical Maximum Units
Frequency, +25 °C Nominal Frequency fC2, 3, 4, 5 403.475 403.625 MHz
Tolerance from 403.055 MHz fC±75 kHz
Insertion Loss IL 2, 5, 6 1.1 1.5 dB
Quality Factor Unloaded Q QU5, 6, 7 16,400
50 Loaded Q QL2,000
Temperature Stability Turnover Temperature TO
6, 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, 6 10 ppm/yr
DC Insulation Resistance between Any Two Terminals 5 1.0 M
RF Equivalent RLC Model Motional Resistance RM
5, 6, 7, 9
14
Motional Inductance LM90 µH
Motional Capacitance CM1.7 fF
Shunt Static Capacitance CO5, 6, 9 1.5 2.1 pF
Test Fixture Shunt Inductance LTEST 2, 7 75 nH
Lid Symbolization 824 // YYWWS
• Designed for 403.55 MHz Transmitters
• Very Low Series Resistance
• Quartz Stability
• Surface-mount Ceramic Case
• Complies with Directive 2002/95/EC (RoHS)
The RO3120A is a one-port, surface-acoustic-wave (SAW) resonator packaged in a surface-mount ceramic
case. It provides reliable, fundamental-mode quartz frequency stabilization of fixed-frequency transmitters
operating at 403.55 MHz.
Absolute Maximum Ratings
Rating Value Units
CW RF Power Dissipation (See Typical Test Circuit) +5 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
403.55 MHz
SAW
Resonator
RO3120A
CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.
NOTES:
1. Frequency aging is the change in fC with time and is specified at +65°C or
less. Aging may exceed the specification for prolonged temperatures
above +65 °C. Typically, aging is greatest the first year after manufacture,
decreasing in subsequent years.
2. The center frequency, fC, is measured at the minimum insertion loss point,
ILMIN, with the resonator in the 50 test system (VSWR 1.2:1). The
shunt inductance, LTEST
, is tuned for parallel resonance with CO at fC.
Typically, fOSCILLATOR or fTRANSMITTER is approximately 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 temperature TC= +25 ± 2 °C.
6. The design, manufacturing process, and specifications of this device are
subject to change without notice.
7. Derived mathematically 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)
frequency, fO. The nominal frequency at any case temperature, TC, may be
calculated from: f = fO[1 - FTC (TO-TC)2]. Typically oscillator TO is
approximately equal to the specified resonator TO.
9. This equivalent RLC model approximates resonator performance near the
resonant frequency and is provided for reference only. The capacitance CO
is the static (nonmotional) capacitance between the two terminals
measured at low frequency (10 MHz) with a capacitance meter. The
measurement includes parasitic capacitance with "NC” pads unconnected.
Case parasitic capacitance is approximately 0.05 pF. Transducer parallel
capacitance can by calculated as: CPCO-0.05pF.
SM5035-4
Pb
©2010-2014 by Murata Electronics N.A., Inc.
RO3120A (R) 4/18/14 Page 2 of 2 www.murata.com
Electrical Connections
The SAW resonator is bidirectional and may be
installed with either orientation. The 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, at FC.
Typical Application Circuits
Equivalent RLC 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
Network Analyzer
To 50
Network Analyzer
50 Source
at FCREFLECTED
INCIDENT
P
P
Low-Loss
Matching
Network to
50
Terminal
Terminal
NC NC
POWER TEST
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
200k
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 - 3.01 - - 0.119 -
K - 1.44 - - 0.057 -
L - 1.92 - - 0.076 -
L
M
C
M
R
M
C
S
C
P
C
P
= 0 . 0 5 p F ( C a s e P a r a s i t i c s )
C
S
= S A W S t a t i c C a p a c i t a n c e
C
O
= C
S
+ C
P
-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
HH
I
H
J
I
H
I
K
L
PCB Land Pattern
Top View
