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NXP Semiconductors BF909R,235
- Part No.:
- BF909R,235
- Manufacturer:
- NXP Semiconductors
- Category:
- Single FETs, MOSFETs
- Package:
- SOT-143R
- Datasheet:
-
BF909R,235.pdf
- Description:
- RF MOSFET 5V SOT143R
- Quantity:
- Payment:
- Shipping:
Inventory:6,099
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Product details
Overview
BF909R,235 from NXP Semiconductors is an N-channel dual-gate MOSFET in SOT143R package, designed for low-noise VHF/UHF amplifier stages operating at 5 V supply. It delivers 43 mS typical forward transfer admittance, 3.6–4.3 pF gate-1 input capacitance, and 2.0–2.8 dB noise figure at 800 MHz - enabling high-gain, low-distortion signal amplification in TV tuners and professional RF receivers.
For engineers reviewing the BF909R,235 datasheet, BF909R,235 pinout, BF909R,235 application, or BF909R,235 equivalent, key selection criteria include its dual-gate AGC capability, cross-modulation performance below −100 dBµV at 1% distortion, thermal resistance of 550 K/W (junction-to-ambient), and guaranteed operation up to 150 °C junction temperature.
Technical Context
This device implements a monolithic enhancement-mode dual-gate structure with internally connected source and substrate, optimized for automatic gain control (AGC) stability in broadband RF front-ends. Its gate-1 threshold voltage (0.3–1.0 V) and gate-2 biasing (4 V typical) enable precise gain regulation without external bias networks.
The BF909R,235 achieves superior cross-modulation suppression via internal bias circuitry that maintains constant transconductance under varying signal levels. Its 35–50 fF reverse transfer capacitance and 2.3–3.0 pF gate-2 input capacitance minimize feedback and support stable 1 GHz small-signal amplification.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDS max | 7 V - supports operation across 3–7 V supply rails common in tuner modules |
| |yfs| typ | 43 mS - enables high-voltage gain (>15 dB) in single-stage 50 Ω RF amplifiers |
| Cig1-s | 3.6–4.3 pF - low gate-1 input capacitance preserves Q-factor in tuned VHF tank circuits |
| Noise figure | 2.0–2.8 dB at 800 MHz - meets stringent SNR requirements for UHF digital TV reception |
| Ptot | 200 mW - sufficient for continuous-wave operation in compact SOT143R surface-mount layout |
| Rth j-a | 550 K/W - defines maximum allowable ambient temperature (≤40 °C) for full-power operation |
| Fmin | 2.00 dB at 800 MHz - specifies minimum achievable noise figure under optimal source impedance |
Pinout & Package
BF909R,235 is housed in a plastic microminiature SOT143R package (3.0 × 1.4 × 0.95 mm), optimized for high-frequency PCB layouts with minimal parasitic inductance. The package features gull-wing leads and is supplied in antistatic tape-and-reel format.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | s, b | Source and substrate connection - must be DC-grounded and RF-bypassed for stable AGC behavior |
| 2 | d | Drain - connects to collector load (e.g., 50 Ω resistor or tuned circuit) and DC supply via RF choke |
| 3 | g2 | Gate 2 - primary RF input node; biased at 4 V for optimal noise/gain trade-off |
| 4 | g1 | Gate 1 - AGC control input; accepts variable DC bias (0.5–1.5 V) to adjust gain linearly |
Key Features
| Feature | Design Value |
|---|---|
| Dual-gate AGC architecture | Enables >30 dB gain control range with <1% cross-modulation distortion at 50 MHz offset |
| Low 5-V operation | Guaranteed functionality at 5 V supply - eliminates need for dedicated high-voltage bias rails |
| High yfs/Cig1-s ratio | ~11.4 mS/pF - maximizes gain-bandwidth product for compact VHF/UHF amplifier designs |
| Optimized noise performance | Fmin = 2.00 dB at 800 MHz with Γopt = 0.603∠67.7° - simplifies matching network design |
| Thermal robustness | 150 °C max junction temperature - supports operation in sealed tuner enclosures without forced cooling |
Applications
| Television Tuner Front-End | Professional UHF Receiver |
|---|---|
Use Scenario: Amplifying weak terrestrial DVB-T signals in 470–862 MHz band prior to mixer stage. IC Role / Device Role / Timing Role: Low-noise RF amplifier with AGC-controlled gain staging to prevent saturation during signal fading. Use Value: Achieves 2.2 dB noise figure and >15 dB gain while maintaining <−105 dBµV cross-modulation at 1% distortion. |
Use Scenario: First-stage LNA in portable spectrum analyzers covering 100–1000 MHz. IC Role / Device Role / Timing Role: Broadband small-signal amplifier with stable gain over temperature and supply variation. Use Value: Delivers flat 12–14 dB gain from 200–900 MHz with <0.5 dB gain deviation across 0–70 °C ambient. |
| FM Radio IF Amplifier | Wireless Microphone Receiver |
Use Scenario: Intermediate frequency amplification at 10.7 MHz in analog FM radio receivers. IC Role / Device Role / Timing Role: High-linearity dual-gate amplifier suppressing intermodulation from adjacent channels. Use Value: Maintains >70 dB SFDR at 10.7 MHz with 15 mA quiescent current and 5 V supply. |
Use Scenario: RF preamplifier in 863–865 MHz license-free wireless microphone systems. IC Role / Device Role / Timing Role: Low-power, low-noise gain block compensating antenna cable loss before demodulation. Use Value: Provides 13 dB gain and 2.5 dB noise figure at 864 MHz with only 15 mA drain current. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-gate MOSFET amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BF998,215 | Higher |yfsig1-s (2.8 pF), but requires 12 V supply for optimal noise performance | Better suited for wideband 100–2000 MHz applications where higher supply voltage is available | Select BF998,215 only if system supports ≥12 V rail and needs extended bandwidth beyond 1 GHz |
| MRF901T1 | Single-gate LDMOS, higher Ptot (500 mW), wider VDS range (12 V), but no intrinsic AGC capability | Requires external AGC circuitry; used in higher-power transmitter driver stages, not receiver LNAs | Choose MRF901T1 only when replacing failed power amplifiers - not as direct BF909R,235 functional substitute |
Compared with BF909R,235, BF998,215 offers higher gain-bandwidth but sacrifices 5 V compatibility, while MRF901T1 provides greater output power at the cost of AGC integration and noise performance - making BF909R,235 uniquely suited for low-voltage, low-noise, AGC-coupled VHF/UHF receiver front-ends.
Availability
BF909R,235 is available at Aetrix Electronics and suitable for television tuner modules, professional UHF receivers, FM radio IF amplifiers, and wireless microphone front-ends requiring stable component supply with consistent parametric performance across production lots.
Supply support for BF909R,235 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in high-performance analog, RF, and mixed-signal solutions for automotive, industrial, and consumer markets.
The BF909R,235 belongs to NXP's legacy RF transistor portfolio, specifically engineered for low-noise, dual-gate amplifier applications in broadcast and communications equipment operating at 3–7 V supply.
FAQ
What is the maximum drain-source voltage rating for BF909R,235?
The BF909R,235 has a maximum drain-source voltage (VDS) rating of 7 V, as specified in the Absolute Maximum Ratings table. This limit applies under all operating conditions and must not be exceeded to prevent permanent device damage. Operation at 5 V is recommended for optimal noise and linearity performance, aligning with its design intent for low-voltage tuner applications.
Does BF909R,235 support automatic gain control (AGC) without external components?
Yes, BF909R,235 integrates an internal bias circuit that enables effective AGC operation using only gate-1 (pin 4) as the control input. When gate-2 (pin 3) is biased at 4 V and drain current is set to 15 mA, applying 0.5–1.5 V to gate-1 adjusts gain linearly while maintaining low cross-modulation - eliminating need for external AGC diodes or op-amps in standard TV tuner designs.
What is the thermal resistance from junction to ambient for BF909R,235?
The BF909R,235 has a thermal resistance from junction to ambient (Rth j-a) of 550 K/W when mounted on a standard PCB, as documented in the Thermal Characteristics section. This value reflects the SOT143R package's thermal path and defines the maximum allowable ambient temperature (≤40 °C) for continuous 200 mW power dissipation without exceeding the 150 °C junction limit.
How does BF909R,235 differ from BF909 in terms of package and thermal performance?
The BF909R,235 uses the SOT143R package (with modified lead geometry per Fig.20), whereas BF909 uses SOT143. This results in a higher junction-to-ambient thermal resistance for BF909R,235 (550 K/W vs. 500 K/W for BF909) and a lower maximum ambient temperature rating (40 °C vs. 50 °C) at full 200 mW power dissipation - a trade-off for improved high-frequency lead inductance control.
What is the typical noise figure of BF909R,235 at 800 MHz?
The BF909R,235 exhibits a typical noise figure of 2.0 dB at 800 MHz under standard test conditions (VDS = 5 V, VG2-S = 4 V, ID = 15 mA, source impedance matched to Γopt). The maximum specified noise figure is 2.8 dB, confirming its suitability for demanding UHF digital TV and spectrum analysis applications where signal integrity is critical.
BF909R,235 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- SOT-143R
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Technology:
- MOSFET (Metal Oxide)
- Configuration:
- N-Channel Dual Gate
- Frequency:
- 800MHz
- Gain:
- -
- Voltage - Test:
- 5 V
- Current Rating (Amps):
- 40mA
- Noise Figure:
- 2dB
- Current - Test:
- 15 mA
- Power - Output:
- -
- Voltage - Rated:
- 7 V
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-143R
BF909R,235 FAQ
1.How can I place an order for BF909R,235 through Aetrix?
Please submit a Request for Quotation (RFQ) for BF909R,235 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for BF909R,235 reliable?
The price and inventory of BF909R,235 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BF909R,235 is usually 5 days.
3.What payment methods are accepted for BF909R,235?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BF909R,235 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BF909R,235?
BF909R,235 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BF909R,235 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for BF909R,235?
For technical support, including BF909R,235 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BF909R,235 requirements.
6.How does Aetrix verify that BF909R,235 is sourced from the original manufacturer or authorized distributors?
All BF909R,235 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BF909R,235 meets industry standards.
7.What is the process for return or replacement of BF909R,235?
All BF909R,235 units undergo pre-shipment inspection (PSI). If there is an issue with BF909R,235, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The BF909R,235 part is unused and in its original packaging.
Return procedure for BF909R,235:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BF909R,235 Tags
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3SK294(TE85L,F)
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SAV-551+
Mini-Circuits
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TAV2-501+
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CEL
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AFT05MS004NT1
NXP USA Inc.
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SAV-541+
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CE3512K2-C1
CEL
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AFM907NT1
NXP Semiconductors
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SKY65050-372LF
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CE3520K3-C1
CEL
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AFT09MS007NT1
NXP USA Inc.
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AFT09MS015NT1
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