FSF-5050 Series · SAW Bandpass Filter
433, 433.92 & 435 MHz SAW Bandpass Filters
FSF-5050-433M · FSF-5050-433M92 · FSF-5050-435M
Compare passband options and matching requirements for RF receiver and IF signal selection.
Model Selection
Choose the Frequency and Filter Configuration
Specified passband ranges and 3 dB bandwidth describe different requirements. Similar frequency markings or package dimensions do not establish interchangeability.
Specified passband
FSF-5050-433M
433 MHz
Center frequency (Typ.) · 429–437 MHz passband
- Insertion loss (Typ. / Max.)
- 2.7 dB / 4.5 dB
- Operating temperature
- −20 to +75 °C
- Test terminations
- 50 Ω / 50 Ω with 0 pF parallel
- Max. input / DC
- 0 dBm / 10 V
3 dB bandwidth
FSF-5050-433M92
433.92 MHz
Center frequency (Typ.) · 0.95 MHz typ. 3 dB bandwidth
- ILmin (Typ. / Max.)
- 3.0 dB / 4.0 dB
- Operating temperature
- −40 to +85 °C
- Matching
- 57 nH series + 8 pF shunt per port
- Max. input / DC
- 10 dBm / 3 V
Specified passband
FSF-5050-435M
435 MHz
Center frequency (Typ.) · 430–440 MHz passband
- Insertion loss (Typ. / Max.)
- 2.3 dB / 3.3 dB
- Operating temperature
- −40 to +85 °C
- Matching
- No matching network for 50 Ω operation
- Max. input / DC
- 10 dBm / 3 V
Specified passband ranges and 3 dB bandwidth describe different requirements. Similar frequency markings or package dimensions do not establish interchangeability.
Electrical Specifications
Six Key Parameters per Model
Min., Typ. and Max. retain their source meanings. “—” means no value is specified for that column, not zero; uncategorized values are stated in the conditions column.
FSF-5050-433M
Scroll horizontally to view all columns.
| Parameter | Min. | Typ. | Max. | Unit | Definition / condition |
|---|---|---|---|---|---|
| Center frequency | — | 433 | — | MHz | Typical |
| Specified passband | — | — | — | MHz | 429–437 MHz; 3 dB bandwidth not specified |
| Insertion loss | — | 2.7 | 4.5 | dB | 429–437 MHz |
| Amplitude ripple | — | 0.7 | 2.5 | dB | 429–437 MHz |
| Operating temperature | −20 | — | +75 | °C | Operating limits |
| Test source / load impedance | — | 50 / 50 | — | Ω | Source / load each 50 Ω with 0 pF parallel capacitance |
No reference measurement temperature is specified. The 50 Ω values describe test terminations, not an additional FCom intrinsic-device impedance specification. The maximum input power is 0 dBm; retain this model-specific limit.
FSF-5050-433M92
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| Parameter | Min. | Typ. | Max. | Unit | Definition / condition |
|---|---|---|---|---|---|
| Center frequency | — | 433.92 | — | MHz | Typical |
| Minimum insertion loss, ILmin | — | 3.0 | 4.0 | dB | Reference for passband and stopband attenuation |
| 3 dB bandwidth | 0.50 | 0.95 | — | MHz | Relative to ILmin |
| Passband attenuation | — | 0.7 | 3.0 | dB | 433.67–434.17 MHz; relative to ILmin |
| Operating temperature | −40 | — | +85 | °C | Operating limits |
| Device impedance at fC | — | — | — | R ∥ C | Input and output each 768 Ω ∥ 2.7 pF; no Min./Typ./Max. category stated in the FCom table |
The supplied data state an electrical reference temperature range of −40 to +85 °C. Measurements use 50 Ω source/load ports with external matching. The passband attenuation is not an amplitude-ripple specification. The 3 dB bandwidth and the specified passband interval are separate entries.
FSF-5050-435M
Scroll horizontally to view all columns.
| Parameter | Min. | Typ. | Max. | Unit | Definition / condition |
|---|---|---|---|---|---|
| Center frequency | — | 435 | — | MHz | Typical |
| Specified passband | — | — | — | MHz | 430–440 MHz; 3 dB bandwidth not specified |
| Insertion loss | — | 2.3 | 3.3 | dB | 430–440 MHz |
| Amplitude ripple | — | 0.8 | 1.7 | dB | 430–440 MHz |
| Operating temperature | −40 | — | +85 | °C | Operating limits |
| Test source / load impedance | — | 50 / 50 | — | Ω | Source / load test terminations |
The supplied FCom document states that no matching network is required for 50 Ω operation. This condition is specific to FSF-5050-435M. No reference measurement temperature is specified. The full datasheet includes a single-frequency attenuation limit at 455 MHz; it must not be extended to an unspecified band.
For 433M and 435M, stopband attenuation is absolute and referenced to 0 dB. For 433M92, the listed passband and stopband attenuation values are relative to ILmin. Refer to the combined FCom PDF for complete attenuation bands, storage limits and maximum ratings.
Typical Applications
Application Fit
Receiver front-end filtering
Use the 433 MHz or 435 MHz option when the specified signal band, insertion loss and rejection requirements suit the receiver front end.
433.92 MHz channel filtering
Evaluate the narrowband option using both its 3 dB bandwidth and passband attenuation limits. Preserve the stated external matching and temperature conditions.
Custom RF / IF band selection
Choose the model that fits the required frequency, signal bandwidth, source/load conditions and input limits. Check the full rejection data for the expected out-of-band signals.
Integration Notes
Match the Interface to the Selected Model
433 MHz
The supplied test terminations are 50 Ω with 0 pF parallel capacitance at both source and load. Preserve the 0 dBm maximum input-power limit and 10 V maximum DC rating.
The reference test circuit uses direct connections. Do not interpret the stated 0 pF test condition as a claim of zero PCB parasitic capacitance.
433.92 MHz
Each port uses a 57 nH series inductance with an 8 pF shunt capacitance on the source/load side of the inductor. The analyzer source and load are 50 Ω.
Each device port is specified as 768 Ω ∥ 2.7 pF at the center frequency. Test terminations and device impedances are different quantities.
435 MHz
The supplied FCom data state that no matching network is required for 50 Ω operation. Confirm that the actual circuit presents the intended source and load conditions.
Connect signal and ground pads according to the FCom pin table below and confirm the mounting view before PCB release.
Package & Pin Assignment
Shared 5.0 × 5.0 mm, Eight-Pad Package
All three supplied FCom pages show a 5.0 × 5.0 mm, 8-pad leadless SMD package with a maximum height of 1.5 mm.
Use the applicable FCom drawing in the combined datasheet for pad dimensions and confirm the mounting view before PCB release. The photograph does not define pad orientation.
Pins 2 and 6 are labeled Input/Output in the FCom document. Confirm the required signal direction and complete ordering configuration. Contact FCom for other pin-configuration requirements.
| Pin(s) | FCom function |
|---|---|
| 2 | Input / Output |
| 6 | Input / Output |
| 1, 3 | Ground |
| 5, 7 | Ground |
| 4 | Case ground |
| 8 | Case ground |
Selection and Design-In Support
Discuss Your Signal Path with FCom
Share the selected model, required passband and bandwidth definition, source/load requirements, matching configuration, temperature range, input power and DC conditions. Include sample quantity and estimated usage.
Confirm the applicable FCom production specification, pin configuration and complete ordering code before design release.
Engineering Questions
Frequently Asked Questions
Are the passband ranges the same as 3 dB bandwidth?
No. FSF-5050-433M specifies performance over 429–437 MHz, and FSF-5050-435M over 430–440 MHz; neither lists a 3 dB bandwidth. FSF-5050-433M92 separately specifies a 3 dB bandwidth of 0.50 MHz minimum and 0.95 MHz typical, relative to ILmin.
What matching does the 433.92 MHz model use?
The supplied configuration uses 50 Ω source and load ports with a 57 nH series inductance at each filter port and an 8 pF shunt capacitance to ground on the source/load side of each inductor. Device input and output impedances at the center frequency are each 768 Ω in parallel with 2.7 pF. Verify the layout and components against the applicable FCom specification.
Does the 433 MHz model have the same power limit as the other two?
No. The supplied FSF-5050-433M document lists a maximum input power of 0 dBm and maximum DC voltage of 10 V. FSF-5050-433M92 and FSF-5050-435M each list 10 dBm and 3 V. Do not transfer another model’s ratings to the selected part.
Are parts with the same frequency marking interchangeable?
A frequency marking alone does not establish interchangeability. Check the exact model, bandwidth definition, insertion-loss limits, operating temperature, device impedance, matching network and pin assignment. This page describes only the three configurations in the supplied FCom datasheet.
What temperature conditions apply to the electrical data?
The 433.92 MHz document states an electrical reference temperature range of −40 to +85 °C. A reference measurement temperature is not specified for the supplied 433 MHz or 435 MHz data. Keep these statements separate from each model’s operating and storage limits; do not substitute an assumed 25 °C condition.
What should I include in a selection inquiry?
Provide the selected model or frequency, required passband and bandwidth definition, source/load requirements, matching configuration, operating temperature, input power and DC conditions, sample quantity and estimated usage. Confirm the applicable production specification and complete ordering code before design release.