Electrical Connections
Equivalent LC Model
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
0.05 pF*
Terminal
+
C
p
=
C
o
0.05 pF
C
p
*Case Parasitics
Terminal
Lm
C m
Rm
recommended to help reduce parasitic
capacitance in the circuit.
Temperature Characteristics
The curve shown on the right
accounts for resonator
Typical Test Circuit
fC = fO , TC = TO
0
0
The test circuit inductor, L
, is tuned to resonate with the static
TEST
-50
contribution only and does not
include LC component
temperature contributions.
-50
capacitance, C , at F .
O
C
-100
-150
-100
-150
-200
-200
-80 -60 -40 -20
ELECTRICAL TEST
0
+40 +60 +80
+20
Typical Circuit Board
Land Pattern
The circuit board land pattern
T = TC - TO ( °C )
Δ
Ω
Ω
To 50
Network Analyzer
From 50
Network Analyzer
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
(4 Places)
P
INCIDENT
Terminal
NC
Terminal
Low-Loss
Matching
Network to
Typical Dimension:
0.010 to 0.047 inch
(0.25 to 1.20 mm)
Ω
at FC
50 Source
NC
P
REFLECTED
Ω
50
Case Design
P
P
INCIDENT - REFLECTED
CW RF Power Dissipation =
Top View
Side View
Bottom View
B
C
E (3x)
F (4x)
Typical Application Circuits
Typical Low-Power Transmitter Application
+9VDC
4
Ω
200k
Modulation
Input
47
C1
C2
3
1
L1
(Antenna)
2
G (1x
RF Bypass
RO3XXXA
Bottom View
D
470
Millimeters
Inches
Nom
Dimension
Typical Local Oscillator Applications
s
Min
Nom
Max
Min
Max
Output
A
B
C
D
E
F
4.87
3.37
1.45
1.35
.67
5.0
3.5
5.13
3.63
1.60
1.50
.93
.191
.132
.057
.040
.026
.014
.042
.196
.137
.060
.057
.031
.019
.047
.201
.142
.062
.059
.036
.024
.052
+VDC
C1
+VDC
1.53
1.43
.80
L1
C2
.37
.50
.63
G
1.07
1.20
1.33
RO3XXXA
Bottom View
RF Bypass
www.RFM.com
E-mail: info@rfm.com
Page 2 of 2
©2008 by RF Monolithics, Inc.
RO3103A - 3/26/08
RFM [ RF MONOLITHICS, INC ]
