FSF-5050 Series · SAW Bandpass Filters
611, 616.25 & 618.25 MHz SAW Bandpass Filters
FSF-5050-611M / 616M25 / 618M25
Three frequency options for UHF receiver filtering and preselection, in a 5.0 × 5.0 mm, 8-pad SMD package. Select by center frequency, bandwidth definition and operating temperature.
Model Selection
Choose the Frequency and Specification You Need
The combined FCom datasheet covers 611 MHz on page 1, 616.25 MHz on page 2 and 618.25 MHz on page 3. Bandwidth definitions and temperature ranges differ; compare each model with its own conditions.
Combined FCom datasheet · Page 1
FSF-5050-611M
611 MHz
Typical center frequency. Uses a 3 dB bandwidth definition and ILmin.
- 3 dB bandwidth
- 7.0 MHz min. / 9.8 MHz typ.
- ILmin
- 2.3 dB typ. / 2.6 dB max.
- Operating temperature
- −20 to +70 °C
ILmin is the minimum passband attenuation; the 3 dB bandwidth is measured relative to ILmin.
Combined FCom datasheet · Page 2
FSF-5050-616M25
616.25 MHz
Typical center frequency. Uses a 2 dB bandwidth definition and center-frequency loss.
- 2 dB bandwidth
- 2.5 MHz min. / 8.0 MHz typ.
- Loss at 616.25 MHz
- 2.3 dB typ. / 3.5 dB max.
- Operating temperature
- 0 to +50 °C
Insertion loss is specified at the center frequency, not across the full 2 dB bandwidth.
Combined FCom datasheet · Page 3
FSF-5050-618M25
618.25 MHz
Typical center frequency. Uses a 2 dB bandwidth definition and center-frequency loss.
- 2 dB bandwidth
- 2.5 MHz min. / 8.0 MHz typ.
- Loss at 618.25 MHz
- 2.4 dB typ. / 3.5 dB max.
- Operating temperature
- 0 to +50 °C
Insertion loss is specified at the center frequency, not across the full 2 dB bandwidth.
Compare definitions before numbers. A 3 dB bandwidth is not equivalent to a 2 dB bandwidth. The 611 MHz ILmin value also uses a different definition from the center-frequency loss of the other models. A shared package does not establish electrical interchangeability.
Electrical Specifications
Six Key Parameters, Model by Model
Each model has six key specifications below. Typical values are for design guidance; confirm applicable production limits before release. A dash (—) means not specified or not applicable in that column, not zero.
Scroll horizontally to view all columns.
FSF-5050-611M · 611 MHz
| Parameter | Min. | Typ. | Max. | Unit | Definition / condition |
|---|---|---|---|---|---|
| Center frequency | — | 611 | — | MHz | Typical value |
| Insertion loss (ILmin) | — | 2.3 | 2.6 | dB | Minimum passband attenuation |
| 3 dB bandwidth | 7.0 | 9.8 | — | MHz | Relative to ILmin |
| Amplitude ripple | — | 0.4 | 1.3 | dB | Over 609.5–612.5 MHz |
| Operating temperature | −20 | — | +70 | °C | Operating limits |
| Storage temperature | −40 | — | +85 | °C | Storage limits |
ILmin is the minimum passband attenuation. The 3 dB bandwidth is measured relative to ILmin. Test source / load: 50 Ω / 50 Ω with direct connections. Device impedances and measurement temperature are not specified in the supplied FCom table.
FSF-5050-616M25 · 616.25 MHz
| Parameter | Min. | Typ. | Max. | Unit | Definition / condition |
|---|---|---|---|---|---|
| Center frequency | — | 616.25 | — | MHz | Typical value |
| Insertion loss at Fc | — | 2.3 | 3.5 | dB | At 616.25 MHz |
| 2 dB bandwidth | 2.5 | 8.0 | — | MHz | 2 dB bandwidth |
| Amplitude ripple | — | 0.3 | 1.5 | dB | Over 615–617.5 MHz |
| Operating temperature | 0 | — | +50 | °C | Operating limits |
| Storage temperature | −40 | — | +85 | °C | Storage limits |
Insertion loss is specified at 616.25 MHz, not across the entire 615–617.5 MHz ripple interval. Test source / load: 50 Ω / 50 Ω with direct connections. Device impedances and measurement temperature are not specified in the supplied FCom table.
FSF-5050-618M25 · 618.25 MHz
| Parameter | Min. | Typ. | Max. | Unit | Definition / condition |
|---|---|---|---|---|---|
| Center frequency | — | 618.25 | — | MHz | Typical value |
| Insertion loss at Fc | — | 2.4 | 3.5 | dB | At 618.25 MHz |
| 2 dB bandwidth | 2.5 | 8.0 | — | MHz | 2 dB bandwidth |
| Amplitude ripple | — | 0.2 | 1.5 | dB | Over 617–619.5 MHz |
| Operating temperature | 0 | — | +50 | °C | Operating limits |
| Storage temperature | −40 | — | +85 | °C | Storage limits |
Insertion loss is specified at 618.25 MHz, not across the entire 617–619.5 MHz ripple interval. Test source / load: 50 Ω / 50 Ω with direct connections. Device impedances and measurement temperature are not specified in the supplied FCom table.
Typical Applications
UHF Filtering Around the Selected Center Frequency
UHF Receiver Filtering
Select the 611, 616.25 or 618.25 MHz model for the intended receiver frequency, then evaluate bandwidth, loss and ripple against the circuit requirements.
Receiver Preselection
Provide frequency-selective filtering ahead of a receiver stage. Confirm the required rejection and interface behavior in the actual system.
Test and Measurement
Use the appropriate frequency option for filtering in measurement signal chains, retaining the model-specific loss definition and ripple interval during evaluation.
Integration Notes
Keep Each Model’s Conditions Separate
Test Terminations and Device Impedance
The supplied FCom pages specify direct connections with 50 Ω source and load test terminations for all three models. These are evaluation conditions, not specified device impedances. Assess the actual source, load and PCB parasitics before deciding whether matching is required.
Bandwidth and Loss Definitions
For 611 MHz, retain ILmin and its relative 3 dB bandwidth definition. For 616.25 and 618.25 MHz, keep center-frequency loss separate from ripple over a band. Do not compare 3 dB bandwidth to 2 dB bandwidth directly.
Operating Temperature
Check the operating range: −20 °C to +70 °C for 611 MHz; 0 °C to +50 °C for the other two models. Storage limits do not extend the operating range.
Pin Labels
Follow the model-specific signal-pin labels in the table below and verify pad orientation against the applicable FCom drawing. A shared package does not establish pin compatibility across models.
Package & Pin Assignment
5 × 5 mm, 8-Pad SMD Package — Model-Specific Pins
All three supplied FCom pages specify a 5.0 × 5.0 mm, 8-SMD package with a maximum height of 1.5 mm. Signal-pin labels differ, so use the column for the selected model.
- Body dimensions
- 5.0 × 5.0 mm
- Maximum height
- 1.5 mm
- Package type
- 8-SMD, no lead
The table preserves the FCom labels; Input/Output does not establish verified bidirectional equivalence. Product photographs identify the lid and pad sides and are not footprint drawings. Consult the applicable PDF page before layout release; contact FCom for other pin configurations.
| Pad(s) | FSF-5050-611M | FSF-5050-616M25 | FSF-5050-618M25 |
|---|---|---|---|
| 2 | Input/Output | Input | Input |
| 6 | Input/Output | Output | Output |
| 1, 3, 5, 7 | Ground | Ground | Ground |
| 4, 8 | Case ground | Case ground | Case ground |
Selection and Design-In Support
Define the Frequency, Bandwidth and Conditions Together
Share the selected model, center frequency, required bandwidth and its dB definition, source and load requirements, operating temperature, sample quantity and estimated usage. Include package or pin constraints that could affect compatibility.
The displayed model names are not confirmed complete ordering codes. Confirm the ordering configuration and applicable specifications with FCom before ordering.
Engineering Questions
Frequently Asked Questions
Which model should I select?
Start with the required frequency: 611, 616.25 or 618.25 MHz. Then check the bandwidth definition and temperature range. The 611 MHz model uses a 3 dB bandwidth and operates from −20 °C to +70 °C; the 616.25 and 618.25 MHz models use 2 dB bandwidths and operate from 0 °C to +50 °C.
What does ILmin mean for the 611 MHz model?
ILmin is the minimum passband attenuation, with a typical value of 2.3 dB and a maximum of 2.6 dB in the supplied FCom datasheet. Its 3 dB bandwidth is measured relative to ILmin. This loss definition must not be relabeled as insertion loss at the center frequency or as a maximum loss across the ripple band.
Are the bandwidth and ripple figures directly comparable?
The 611 MHz model specifies a 3 dB bandwidth of 7.0 MHz minimum and 9.8 MHz typical. The other two models specify 2 dB bandwidths of 2.5 MHz minimum and 8.0 MHz typical. Ripple is measured over a different stated interval for each model. Compare values only when their definitions and conditions match.
Does direct testing with 50 Ω terminations mean matching is unnecessary?
No. The supplied FCom pages specify direct connections with 50 Ω source and load test terminations. They do not specify the device input or output impedance. Assess the actual source, load and PCB before deciding whether matching is needed.
Do all three models have the same signal-pin labels?
No. FSF-5050-611M labels pads 2 and 6 as Input/Output. FSF-5050-616M25 and FSF-5050-618M25 label pad 2 as Input and pad 6 as Output. All three list pads 1, 3, 5 and 7 as ground, and pads 4 and 8 as case ground. Confirm orientation using the applicable FCom drawing.
Which PDF page and inquiry details apply to my model?
The combined FCom datasheet covers FSF-5050-611M on page 1, FSF-5050-616M25 on page 2 and FSF-5050-618M25 on page 3. Include the selected model, frequency, bandwidth definition, source and load requirements, temperature range, sample quantity and estimated usage in your inquiry. Confirm the complete ordering code with FCom.