FSF-5050 Series · SAW Bandpass Filter
674 MHz SAW Bandpass Filter
FSF-5050-674M
A 5.0 × 5.0 mm SMD SAW filter with a specified 650–698 MHz passband for UHF receiver and test equipment designs.
Key Features
Define the Passband and Interface
Specified Passband
650–698 MHz
Specified passband with a 48 MHz span. This is not a 3 dB bandwidth specification.
Insertion Loss
3.8 dB typ.
4.6 dB maximum over 650–698 MHz. Allow for filter loss in the receiver gain budget.
Amplitude Ripple
1.4 dB typ.
2.4 dB maximum over 650–698 MHz.
The specified passband 650–698 MHz is a frequency range, not the 3 dB bandwidth. A 3 dB bandwidth is not specified in the supplied datasheet.
Electrical Specifications
Six Key Selection Parameters
Test setup: 50 Ω source and load, with single-ended input and output. The FCom datasheet does not specify device input or output impedance or a uniform measurement temperature for this table.
Scroll horizontally to view all columns.
| Parameter | Min. | Typ. | Max. | Unit | Definition / condition |
|---|---|---|---|---|---|
| Center frequency | — | 674.0 | — | MHz | fc |
| Specified passband | — | — | — | MHz | 650–698 MHz; span 48 MHz |
| Insertion loss | — | 3.8 | 4.6 | dB | Over 650–698 MHz |
| Amplitude ripple | — | 1.4 | 2.4 | dB | Over 650–698 MHz |
| 3 dB bandwidth | — | — | — | MHz | Not specified |
| Operating temperature | −40 | — | +85 | °C | Operating range; not an electrical test condition |
| Storage temperature | −40 | — | +85 | °C | Storage range |
— means not specified, not zero. The passband row gives a frequency range, not Min./Typ./Max. limits. Its 48 MHz span is not a specified 3 dB bandwidth; no 3 dB bandwidth value is provided. Typical values are for design guidance. Refer to the FCom datasheet and confirm applicable production limits with FCom.
Typical Applications
Band Selection from 650 to 698 MHz
UHF Receiver Filtering
Evaluate the specified 650–698 MHz passband for signal selection in a UHF receiver. Check the required insertion loss and amplitude ripple across your occupied signal band.
Receiver Preselector
Consider the filter for frequency selection ahead of a receiver stage. Validate system rejection, insertion loss and signal levels with the intended source and load.
Measurement-Path Filtering
Consider the filter for a measurement path centered on 674 MHz where selection across 650–698 MHz is required. Validate the complete fixture and measurement conditions.
Integration Notes
Match the Evaluation Conditions
Test Setup and Device Impedance
The stated performance uses a 50 Ω source and load. These are test conditions, not a declaration of the device impedance. Assess matching requirements using your actual source, load and board parasitics.
Complete Signal Path
Insertion loss and amplitude ripple are both specified over 650–698 MHz. Evaluate these limits against the complete signal band and required rejection. The 48 MHz span describes the stated passband; it does not establish the 3 dB cutoff frequencies.
Package & Pin Assignment
5 × 5 mm, 8-Terminal SMD Package
The FCom drawing specifies a 5.0 × 5.0 mm body and a maximum height of 1.5 mm. The pin assignments at right apply to FSF-5050-674M.
- Body dimensions
- 5.0 × 5.0 mm
- Maximum height
- 1.5 mm
- Package type
- 8-SMD, no lead
Use the dimension drawing in the FCom datasheet for mechanical review. Its plan-view orientation is not explicitly labeled; confirm orientation and the PCB land pattern before layout release. Contact FCom for other pin configurations.
| Pin(s) | Function |
|---|---|
| 2 | Input |
| 6 | Output |
| 1, 3, 5, 7 | Ground |
| 4, 8 | Case ground |
Selection and Design-In Support
Make the Design Requirements Clear
For selection and design-in discussions, provide the required bandwidth and its definition, source and load requirements, operating temperature, sample quantity and expected usage. Reference FSF-5050-674M and confirm the complete ordering code and applicable production specification with FCom.
The model designation alone is not a confirmed complete ordering code.
Engineering Questions
Frequently Asked Questions
Is 48 MHz the 3 dB bandwidth?
No. 48 MHz is the span of the specified 650–698 MHz passband. Neither the supplied FCom datasheet nor the reference specification provides a numerical 3 dB bandwidth. Do not use the passband endpoints as 3 dB cutoff frequencies.
Where do the insertion-loss and ripple limits apply?
Both apply over 650–698 MHz. Insertion loss is 3.8 dB typical and 4.6 dB maximum; amplitude ripple is 1.4 dB typical and 2.4 dB maximum. These are passband specifications, not measurements stated only at the 674 MHz center frequency.
Does the 50 Ω test setup specify the device impedance?
No. The datasheet uses a 50 Ω source and a 50 Ω load with single-ended input and output. Device input and output impedances are not specified. Evaluate matching with your actual source, load and PCB layout.
How should the ground pins be connected?
The FCom datasheet assigns pin 2 to input and pin 6 to output. Pins 1, 3, 5 and 7 are ground; pins 4 and 8 are case ground. Confirm the drawing orientation and land pattern before PCB release.
What information should I include in a design-in inquiry?
Include FSF-5050-674M, the required signal band, bandwidth definition, loss and ripple requirements, source and load requirements, operating temperature, sample quantity and expected usage. Confirm the complete ordering code and applicable production limits with FCom before ordering.