FSF-5050 Series · Balanced RF Bandpass Filter
1000 MHz Balanced SAW Bandpass Filter
FSF-5050-1000M
Narrowband RF selection at 1 GHz with balanced input and output ports. Evaluate the 2.0 MHz typical 3 dB bandwidth with the specified matching network.
Key features
Match the Passband and Balanced Interface
Center Frequency
1000 MHz
Typical center frequency for balanced RF bandpass filtering at 1 GHz.
3 dB Bandwidth
2.0 MHz typ.
1.5 MHz minimum. Keep the 3 dB criterion separate from the specified passband interval.
Minimum Insertion Loss
3.2 dB typ.
5.0 dB maximum for ILmin, including matching-element loss.
Specified passband: 999.600–1000.400 MHz. Its loss limits are relative to ILmin. This interval and the 3 dB bandwidth describe different requirements; amplitude ripple is not separately specified.
Electrical specifications
Six Key Selection Parameters
Values follow the supplied FCom sheet. Typical values support initial selection; confirm the applicable production specification and test conditions.
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| Parameter | Min. | Typ. | Max. | Unit | Definition / condition |
|---|---|---|---|---|---|
| Center frequency, fc | — | 1000 | — | MHz | Typical value in the electrical table |
| 3 dB bandwidth | 1.5 | 2.0 | — | MHz | 3 dB criterion |
| Minimum insertion loss, ILmin | — | 3.2 | 5.0 | dB | Includes matching-element loss |
| Amplitude ripple | — | — | — | dB | Not separately specified |
| Operating temperature | −30 | — | +70 | °C | Operating range |
| Storage temperature | −40 | — | +85 | °C | Storage range |
“—” means no value is specified. The reference uses 50 Ω balanced test ports and a 22 nH inductor across each balanced port pair. Device input/output impedance and electrical measurement temperature are not separately specified. The operating range is not a statement of the measurement temperature. Refer to the datasheet for the complete supplied information.
Typical applications
Balanced RF Filtering at 1 GHz
Balanced RF Signal Selection
Evaluate narrowband selection around 1000 MHz in a balanced RF signal path. Check signal bandwidth, passband loss and the interface requirements of adjacent stages.
Receiver Preselection
Consider the filter for a receiver path requiring 1 GHz band selection. Include matching-element loss in the receiver gain budget and confirm the required rejection limits.
RF Test & Measurement
Evaluate filtering in a 1000 MHz test path using the specified balanced-port connections and defined measurement reference planes.
Integration notes
Bridge Each Balanced Port with 22 nH
Input Matching
Connect one 22 nH inductor across pins 1 and 2, the balanced input pair. Both pins carry the input signal; neither is identified as an input ground pin.
Output Matching
Connect a second 22 nH inductor across pins 5 and 6, the balanced output pair. The inductor bridges the pair rather than connecting a signal pin to ground.
Test and PCB Conditions
The reference uses 50 Ω balanced test ports and Coilcraft CS series 0805 inductors. Evaluate actual matching components, grounding and PCB parasitics at the intended reference planes.
The stated 50 Ω test-port condition does not separately specify device impedance. Confirm the balanced source/load requirements and any conversion from a single-ended signal path before finalizing the interface.
Package and pin assignment
5.0 × 5.0 mm, Eight-Pad SMD Package
The listed FSF-5050-1000M configuration has two signal pins at each balanced port. Verify the applicable drawing orientation before reusing a PCB footprint.
Confirm the maximum height before layout release. The FCom sheet retains a 1.5 mm maximum-height template and identifies a 1.7 mm reference height. Confirm the applicable height, mechanical drawing and PCB land pattern with FCom.
Pins 3, 4, 7 and 8 are ground. Contact FCom for other pin requirements.
| Pins | Function |
|---|---|
| 1, 2 | Balanced input |
| 5, 6 | Balanced output |
| 3, 4, 7, 8 | Ground |
Selection and design-in support
Define the Passband and Interface Requirements
Share the application, required bandwidth and dB criterion, balanced source/load requirements and operating temperature. Include sample quantity and estimated annual volume.
Ask FCom to confirm the applicable passband limits, matching conditions, mechanical drawing and complete ordering code. State any ripple or rejection requirement that needs explicit agreement.
Engineering questions
Frequently Asked Questions
How do the 2.0 MHz bandwidth and 999.600–1000.400 MHz passband differ?
The 3 dB bandwidth is 1.5 MHz minimum and 2.0 MHz typical. The separately specified 999.600–1000.400 MHz passband is an interval whose loss limits are referenced to minimum insertion loss, ILmin. It is not the same bandwidth definition; confirm the required signal interval and applicable loss limits.
Are the input and output balanced?
Yes. Pins 1 and 2 form the balanced input, and pins 5 and 6 form the balanced output. Pins 3, 4, 7 and 8 are ground. The reference uses 50 Ω balanced test ports; the device input and output impedances are not separately specified.
How are the 22 nH matching inductors connected?
One 22 nH inductor bridges input pins 1 and 2. A second 22 nH inductor bridges output pins 5 and 6. Each inductor is across a balanced port pair, not from a signal pin to ground. The reference inductors are Coilcraft CS series, 0805.
Does the stated insertion loss include the matching network?
Yes. Minimum insertion loss, ILmin, includes matching-element loss: 3.2 dB typical and 5.0 dB maximum. These values do not define the maximum loss at every passband frequency. Amplitude ripple is not separately specified, and passband loss relative to ILmin is not a separate ripple specification.
Which package dimensions need confirmation?
The listed package footprint is 5.0 × 5.0 mm with eight no-lead SMD pads. The FCom sheet retains a 1.5 mm maximum-height template and notes a 1.7 mm reference height. Confirm the applicable maximum height, drawing orientation and PCB land pattern before layout release.
What information should I include in a technical inquiry?
Provide FSF-5050-1000M, the application, required bandwidth and dB criterion, source/load requirements, balanced-interface details, operating temperature, sample quantity and estimated annual volume. Confirm the applicable specification, package drawing and complete ordering code with FCom.