•
•
•
•
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Ideal for European 868.95 MHz Transmitters
Very Low Series Resistance
Quartz Stability
Surface-Mount Ceramic Case with 21 mm
2
Footprint
Complies with Directive 2002/95/EC (RoHS)
RO3156A
RO3156A-1
RO3156A-2
868.95 MHz
SAW
Resonator
The RO3156A 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 fixed-frequency transmitters
operating at 868.95 MHz. This SAW is designed specifically for remote-control and wireless security
transmitters operating under ETSI-ETS 300 220 in Europe and under FTZ 17 TR 2100 in Germany.
Absolute Maximum Ratings
Rating
CW RF Power Dissipation
DC Voltage Between Terminals
Case Temperature
Soldering Temperature (10 seconds / 5 cycles max.)
Value
+5
±30
-40 to +85
260
Units
dBm
VDC
°C
°C
SM5035-4
Electrical Characteristics
Characteristic
Frequency (+25 °C)
RO3156A
RO3156A-1
RO3156A-2
Tolerance from 868.95 MHz
RO3156A
RO3156A-1
RO3156A-2
Nominal Frequency
Sym
f
C
Notes
Minimum
868.750
868.800
868.850
Typical
Maximum
869.150
869.100
869.050
±200
±150
±100
2.0
Units
MHz
2,3,4,5
Δf
C
IL
Q
U
Q
L
T
O
f
O
FTC
|fA|
R
M
L
M
C
M
C
O
L
TEST
2,5,6
5,6,7
kHz
dB
Unloaded Q
50
Ω
Loaded Q
Temperature Stability
Turnover Temperature
Turnover Frequency
Frequency Temperature Coefficient
Frequency Aging
Absolute Value during the First Year
DC Insulation Resistance between Any Two Terminals
RF Equivalent RLC Model
Motional Resistance
Motional Inductance
Motional Capacitance
Shunt Static Capacitance
Test Fixture Shunt Inductance
Lid Symbolization (in addition to Lot and/or Date Codes)
Insertion Loss
Quality Factor
10
6,7,8
1
5
5, 6, 7, 9
5, 6, 9
2, 7
1.2
6200
850
25
f
C
0.032
<±10
40
°C
kHz
ppm/°C
2
ppm/yr
MΩ
Ω
µH
fF
pF
nH
1.0
14.5
18.0
2.0
2.1
15.8
714 // YWWS
CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.
Notes:
1.
Frequency aging is the change in f
C
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.
The center frequency, f
C
, is measured at the minimum insertion loss point,
IL
MIN
, with the resonator in the 50
Ω
test system (VSWR
≤
1.2:1). The
shunt inductance, L
TEST
, is tuned for parallel resonance with C
O
at f
C
.
Typically, f
OSCILLATOR
or f
TRANSMITTER
is approximately equal to the
resonator f
C
.
One or more of the following United States patents apply: 4,454,488 and
4,616,197.
Typically, equipment utilizing this device requires emissions testing and
government approval, which is the responsibility of the equipment
manufacturer.
Unless noted otherwise, case temperature T
C
= +25°C±2°C.
6.
7.
8.
The design, manufacturing process, and specifications of this device are
subject to change without notice.
Derived mathematically from one or more of the following directly
measured parameters: f
C
, IL, 3 dB bandwidth, f
C
versus T
C
, and C
O
.
Turnover temperature, T
O
, is the temperature of maximum (or turnover)
frequency, f
O
. The nominal frequency at any case temperature, T
C
, may be
calculated from: f = f
O
[1 - FTC (T
O
-T
C
)
2
]. Typically
oscillator
T
O
is
approximately equal to the specified
resonator
T
O
.
This equivalent RLC model approximates resonator performance near the
resonant frequency and is provided for reference only. The capacitance C
O
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: C
P
≈
C
O
- 0.05 pF.
2.
3.
4.
5.
9.
www.RFM.com
E-mail: info@rfm.com
©2008 by RF Monolithics, Inc.
Page 1 of 2
RO3156A - 3/27/08
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.
Terminal
Case Ground
Case Ground
Equivalent LC Mode
l
0.05 pF*
Co = Cp + 0.05 pF
Cp
*Case Parasitics
Terminal
Rm
Lm
Cm
Temperature Characteristics
The curve shown on the right
accounts for resonator
contribution only and does not
include LC component
temperature contributions.
f
C
= f
O
, T
C
= T
O
0
(f-fo ) / fo (ppm)
Typical Test Circuit
The test circuit inductor, L
TEST
, is tuned to resonate with the static
capacitance, C
O
, at F
C
.
0
-50
-100
-150
-200
0 +20 +40 +60 +80
-50
-100
-150
-200
-80 -60 -40 -20
ELECTRICAL TEST
From 50
Ω
Network Analyzer
To 50
Ω
Network Analyzer
Typical Circuit
Land Pattern
Board
Δ
T = T
C
- T
O
( °C )
The circuit board land pattern
shown below is one possible design. The optimum land pattern is
dependent on the circuit board assembly process which varies by
manufacturer. The distance between adjacent land edges should be at a
maximum to minimize parasitic capacitance. Trace lengths from terminal
lands to other components should be short and wide to minimize parasitic
series inductances.
POWER TEST
P INCIDENT
(4 Places)
Low-Loss
Matching
Network to
50
Ω
Terminal
NC
NC
Terminal
50
Ω
Source
P
at F
C
REFLECTED
Typical Dimension:
0.010 to 0.047 inch
(0.25 to 1.20 mm)
Case Design
CW RF Power Dissipation =
P INCIDENT - P REFLECTED
Top View
B
Side View
C
Bottom View
E (3x)
Typical Application Circuits
Typical Low-Power Transmitter Application
+9VDC
200k
Ω
L1
(Antenna)
A
4
F (4x)
Modulation
Input
C1
47
3
2
1
C2
RO3XXXA
Bottom View
470
RF Bypass
D
G (1x)
Typical Local Oscillator Applications
Output
+VDC
C1
L1
C2
RO3XXXA
Bottom View
RF Bypass
+VDC
Dimensions Millimeters
Min
Nom
A
B
C
D
E
F
G
4.87
3.37
1.45
1.35
.67
.37
1.07
5.0
3.5
1.53
1.43
.80
.50
1.20
Max
5.13
3.63
1.60
1.50
.93
.63
1.33
Inches
Min
Nom Max
.191
.132
.057
.040
.026
.014
.042
.196
.137
.060
.057
.031
.019
.047
.201
.142
.062
.059
.036
.024
.052
www.RFM.com
E-mail: info@rfm.com
©2008 by RF Monolithics, Inc.
Page 2 of 2
RO3156A - 3/27/08
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