RFM RF3181

RF3181
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Ideal Front-End Filter for 916.5 MHz Wireless Receivers
Low-Loss, Coupled-Resonator Quartz Design
Simple External Impedance Matching
Rugged TO39 Hermetic Package
Complies with Directive 2002/95/EC (RoHS)
Pb
916.50 MHz
SAW Filter
The RF3181 is a low-loss, compact, and economical surface-acoustic-wave (SAW) filter designed to provide
front-end selectivity in 916.5 MHz receivers. Receiver designs using this filter include superhet with 10.7 MHz
or 500 kHz IF, direct conversion and superregen. Typical applications of these receivers are wireless remotecontrol and security devices operating in the USA under FCC Part 15 and in Canada under DoC RSS-210.
This coupled-resonator filter (CRF) uses selective null placement to provide suppression, typically greater
than 40 dB, of the LO and image spurious responses of superhet receivers with 10.7 MHz IF. RFM’s
advanced SAW design and fabrication technology is utilized to achieve high performance and very low loss
with simple external impedance matching (not included). Quartz construction provides excellent frequency
stability over a wide temperature range.
TO39-3 Case
Electrical Characteristics
Characteristic
Sym
Center Frequency at 25°C Absolute Frequency
Tolerance from 916.500 MHz
Insertion Loss
3 dB Bandwidth
Rejection
fC
∆fC
Notes
Typical
Maximum
916.400
916.500
916.600
MHz
±100
kHz
1, 2
IL
1
BW3
1,2
at fC - 21.4 MHz (Image)
at fC - 10.7 MHz (LO)
Minimum
1
3.2
5
dB
600
750
1000
kHz
33
40
15
37
Ultimate
Temperature
Units
dB
80
Operating Case Temp.
TC
Turnover Temperature
TO
Turnover Frequency
fO
-40
3, 4
+85
°C
25
°C
fC
MHz
Freq. Temp. Coefficient
FTC
0.032
ppm/°C2
Frequency Aging
Absolute Value during the First Year
|fA|
5
≤10
ppm/yr
External Impedance
Series Inductance
L
1
Coilcraft 8.2 nH Chip Inductor
Shunt Capacitance
C
1
1
Lid Symbolization (in addition to Lot and/or Date Codes)
nH
5
pF
RFM RF3181
CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.
Notes:
1.
2.
3.
4.
5.
6.
7.
8.
Unless noted otherwise, all measurements are made with the filter installed in the specified test fixture which is connected to a 50 Ω test system with
VSWR ≤ 1.2:1. The test fixture L and C are adjusted for minimum insertion loss at the filter center frequency, fc. Note that insertion loss, bandwidth,
and passband shape are dependent on the impedance matching component values and quality.
The frequency fc is defined as the midpoint between the 3dB frequencies.
Unless noted otherwise, specifications apply over the entire specified operating temperature range.
The 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].
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 significantly in subsequent years.
The design, manufacturing process, and specifications of this device are subject to change without notice.
One or more of the following U.S. Patents apply: 4,54,488, 4,616,197, and others pending.
All equipment designs utilizing this product must be approved by the appropriate government agency prior to manufacture or sale.
www.RFM.com
E-mail: [email protected]
©2008 by RF Monolithics, Inc.
Page 1 of 2
RF3181 - 3/21/08
Absolute Maximum Ratings
Rating
Value
Units
Incident RF Power
+13
dBm
DC Voltage Between Any Two Pins (Observe ESD Precautions)
±30
VDC
-40 to +85
°C
260
°C
Case
Temperature5
Soldering Temperature (10 seconds / 5 cycles max.)
Typical Filter Response
Typical filter responses are shown below. The actual response is
dependent on external impedance matching and circuit layout. Illustrated
frequencies and minimum rejection for LO and IMAGE are shown only for
superhet receivers with 10.7 MHz IF.
0
0
-1
-10
-2
Amplitude Response
Amplitude Response
-20
-30
-40
-50
-3
-4
Min 3dB
Passband
at 25°C
-5
-6
-60
-7
-70
-8
200 kHz/div
Frequency
-80
5 MHz/div
Frequency
Case Design
C
G
B
Electrical Connections
H
Bottom View
Pin
F
Connection
Pin 1
1
2
3
Pin 2
Input or Output
Output or Input
Case Ground
E
A
D
(3 places)
Pin 3
J
(2 places)
45°
Typical Test Circuit
Millimeters
L
From 50Ω
Network
Analyzer
L
1
C
Min
2
3
C
To 50 Ω
Network
Analyzer
Max
A
9.40
B
3.18
C
2.50
3.50
Min
Max
0.370
0.125
0.098
0.138
D
0.46 Nominal
0.018 Nominal
E
5.08 Nominal
0.200 Nominal
F
2.54 Nominal
0.100 Nominal
G
2.54 Nominal
0.100 Nominal
H
J
www.RFM.com
E-mail: [email protected]
©2008 by RF Monolithics, Inc.
Inches
Dimensions
1.02
1.40
0.040
0.055
Page 2 of 2
RF3181 - 3/21/08