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RF Monolithics, Inc.

Phone: (972) 233-2903

Fax: (972) 387-9148

E-mail: info@rfm.com

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RFM Europe

Phone: 44 1963 251383

Fax: 44 1963 251510

http://www.rfm.com

©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.

RO2125-102699

Electrical Characteristics

Characteristic

Sym

Notes

Minimum

Typical

Maximum

Units

Center Frequency (+25 °C)

Absolute Frequency

2, 3, 4, 5

304.225

304.375

MHz

Tolerance from 304.300 MHz

∆f

C

±75

kHz

Insertion Loss

IL

2, 5, 6

0.9

1.5

dB

Quality Factor

Unloaded Q

5, 6, 7

18,300

50

Ω Loaded Q

2,000

Temperature Stability

Turnover Temperature

6, 7, 8

10

25

40

°C

Turnover Frequency

Frequency Temperature Coefficient

FTC

0.037

Frequency Aging

Absolute Value during the First Year

1

≤10

ppm/yr

DC Insulation Resistance between Any Two Pins

5

1.0

M

Ω

RF Equivalent RLC Model

Motional Resistance

5, 7, 9

10

19

Ω

Motional Inductance

95.7126

µH

Motional Capacitance

2.85803

fF

Pin 1 to Pin 2 Static Capacitance

5, 6, 9

2.9

3.2

3.5

pF

Transducer Static Capacitance

5, 6, 7, 9

2.9

pF

Test Fixture Shunt Inductance

2, 7

84

nH

Lid Symbolization (in Addition to Lot and/or Date Code)

RFM RO2125

TO39-3 Case

•

Ideal for 315 MHz LO in Superhet Receivers with 10.7 MHz IF

•

Very Low Series Resistance

•

Quartz Stability

•

Rugged, Hermetic, Low-Profile TO39 Case

•

Complies with Directive 2002/95/EC (RoHS)

The RO2125 is a true one-port, surface-acoustic-wave (SAW) resonator in a low-profile TO39 case. It pro-

vides reliable, fundamental-mode, quartz frequency stabilization of local oscillators operating at 304.3 MHz.

This SAW is designed for 315 MHz superhet receivers with 10.7 MHz IF (Philips UAA3201T). Applications

include automotive-keyless-entry receivers operating in the USA under FCC Part 15, in Canada under DoC

RSS-210, and in Italy.

Absolute Maximum Ratings

Rating

Value

Units

CW RF Power Dissipation (See: Typical Test Circuit)

+0

dBm

DC Voltage Between Any Two Pins (Observe ESD Precautions)

±30

VDC

Case Temperature

-40 to +85

°C

304.3 MHz

SAW

Resonator

RO2125

CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.

Notes:

1.

Aging may exceed the specification for prolonged temperatures above +65°C.

Typically, aging is greatest the first year after manufacture, decreasing signifi-

cantly in subsequent years.

2.

with the resonator in the 50

Ω test system (VSWR ≤ 1.2:1). The shunt induc-

3.

One or more of the following United States patents apply: 4,454,488 and

4,616,197 and others pending.

4.

Typically, equipment designs utilizing this device require emissions testing and

government approval, which is the responsibility of the equipment manufacturer.

5.

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

8.

9.

This equivalent RLC model approximates resonator performance near the reso-

static (nonmotional) capacitance between pin1 and pin 2 measured at low fre-

quency (10 MHz) with a capacitance meter. The measurement includes case

parasitic capacitance with a floating case. For usual grounded case applica-

tions (with ground connected to either pin 1 or pin 2 and to the case), add

Pb