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Nexperia USA Inc. BFS20,235
- Part No.:
- BFS20,235
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BFS20,235.pdf
- Description:
- TRANS NPN 20V 0.025A TO-236AB
- Quantity:
- Payment:
- Shipping:
Inventory:687
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Product details
Overview
BFS20,235 from Nexperia is an NPN medium-frequency transistor in SOT23 package, designed for IF and VHF thick/thin-film circuits. It delivers IC(max) = 25 mA, VCEO(max) = 20 V, fT = 275–450 MHz, Cre = 350 fF (typ.), and hFE = 40–85 at IC = 7 mA / VCE = 10 V - enabling stable amplification in compact RF front-ends.
For engineers reviewing the BFS20,235 datasheet, BFS20,235 pinout, BFS20,235 application, or BFS20,235 equivalent, key selection criteria include its low feedback capacitance, medium-frequency gain-bandwidth trade-off, SOT23 thermal resistance (Rth(j-a) = 500 K/W), and suitability for space-constrained VHF amplifier stages.
Technical Context
The BFS20,235 operates as a general-purpose NPN RF transistor with DC current gain (hFE) specified between 40 and 85 under 7 mA collector bias. Its transition frequency (fT) spans 275–450 MHz, confirming utility in intermediate-frequency and lower VHF bands (e.g., 30–150 MHz).
It features very low feedback capacitance (Cre = 350 fF typ.) and collector capacitance (Cc = 1 pF), minimizing unwanted signal coupling in tuned amplifier designs. Absolute maximum ratings include VCEO = 20 V, VCBO = 30 V, and Ptot = 250 mW at Tamb ≤ 25 °C on FR4 PCB.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 20 V - defines maximum safe collector-emitter voltage in common-emitter configuration |
| fT | 275–450 MHz - determines usable small-signal amplification bandwidth at IC = 5 mA / VCE = 10 V |
| Cre | 350 fF (typ.) - limits Miller-effect feedback to preserve stability in high-gain VHF stages |
| hFE | 40–85 - provides predictable DC biasing and gain control for linear amplifier design |
| Ptot | 250 mW - sets power handling limit on standard FR4 PCB without heatsinking |
| Rth(j-a) | 500 K/W - indicates thermal performance degradation above ambient; requires layout-aware copper pour |
Pinout & Package
SOT23 plastic surface-mounted package (TO-236AB), 3-lead, dimensions per JEDEC outline: 2.9 × 1.3 × 1.0 mm (L × W × H), with 0.95 mm lead pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | DC bias and RF input node; requires impedance-matched drive for stable fT operation |
| 2 | Emitter | Common reference terminal; must be low-inductance grounded in VHF layouts |
| 3 | Collector | RF output and power delivery node; connects to tuned load or next-stage input |
Key Features
| Feature | Design Value |
|---|---|
| Low feedback capacitance | 350 fF typical - reduces instability risk in narrowband VHF amplifiers |
| Medium-frequency fT range | 275–450 MHz - balances gain and bandwidth for IF/VHF fixed-tuned applications |
| SOT23 footprint compatibility | Standard JEDEC TO-236AB - enables automated placement and reflow in high-volume production |
| Controlled hFE spread | 40–85 at 7 mA/10 V - supports consistent bias network design across production lots |
Applications
| FM Radio IF Amplifier | VHF TV Tuner Front-End |
|---|---|
Use Scenario: Amplifies 10.7 MHz IF signal in portable FM radio receivers with minimal distortion. IC Role / Device Role / Timing Role: NPN RF amplifier stage operating in common-emitter configuration with fixed bias. Use Value: Low Cre ensures stable gain at 10.7 MHz without neutralization; SOT23 enables compact double-sided PCB layout. | Use Scenario: Boosts weak VHF band III (174–230 MHz) signals before mixer in analog/digital TV tuners. IC Role / Device Role / Timing Role: First-stage low-noise amplifier (LNA) with tuned collector load. Use Value: fT > 275 MHz supports flat gain response across band III; 250 mW rating accommodates transient overloads. |
| Wireless Microphone Transmitter | Two-Way Radio IF Filter Driver |
Use Scenario: Drives crystal-filtered 49 MHz or 27 MHz carrier in license-free wireless microphones. IC Role / Device Role / Timing Role: Class-A linear driver amplifier preceding crystal filter and antenna matching network. Use Value: hFE consistency allows repeatable output level calibration; low Cc preserves filter Q-factor. | Use Scenario: Buffers and amplifies 455 kHz or 10.7 MHz IF signal after ceramic or SAW filter in PMR radios. IC Role / Device Role / Timing Role: Post-filter gain restoration stage with emitter-degeneration bias. Use Value: 25 mA IC(max) supports headroom for modulation peaks; SOT23 eases routing near high-Q filters. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN medium-frequency transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC847B,215 | fT = 100 MHz (lower), hFE = 200–450 (higher), VCEO = 45 V (higher) | Better DC gain but insufficient fT for >100 MHz VHF use | Select only for IF-only designs ≤ 50 MHz where higher hFE improves bias stability |
| MMBT2222A | fT = 300 MHz (comparable), IC(max) = 600 mA (much higher), SOT23-3 footprint identical | Higher power dissipation changes thermal layout; not optimized for low-Cre VHF | Prefer when driving heavier loads or requiring wider safe operating area, but verify Cre impact on stability |
Compared with BC847B,215 and MMBT2222A, the BFS20,235 uniquely balances VHF fT capability, ultra-low Cre, and tight hFE distribution - making it optimal for fixed-tuned, space-constrained IF/VHF amplifiers where stability and repeatability are critical.
Availability
BFS20,235 is available at Aetrix Electronics and suitable for FM radio IF amplifiers, VHF TV tuner front-ends, wireless microphone transmitters, and two-way radio IF filter drivers requiring stable component supply across industrial and consumer production cycles.
Supply support for BFS20,235 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
Nexperia is a global leader in discrete, logic, and PowerMOS semiconductors, serving automotive, industrial, computing, consumer, and wearable markets with high-volume, high-reliability components.
The BFS20,235 belongs to Nexperia's legacy RF transistor product line, engineered specifically for cost-sensitive, high-yield IF and VHF amplifier applications in consumer electronics and broadcast equipment.
FAQ
Is BFS20,235 suitable for RF power amplification?
No. The BFS20,235 is rated for 25 mA DC collector current and 250 mW total power dissipation - limiting it to small-signal amplification. Its fT and low Cre support linear gain up to ~450 MHz, but it lacks the SOA, thermal robustness, or output power capability required for RF power stages.
What is the recommended bias configuration for VHF amplifier use?
A fixed-current bias using emitter degeneration (e.g., 1–2 kΩ emitter resistor) with base voltage divider is recommended. This stabilizes DC operating point against hFE variation and temperature drift while preserving AC gain via bypass capacitor. Layout must minimize parasitic inductance at emitter and collector nodes.
Does BFS20,235 require neutralization in 100 MHz amplifier designs?
Typically no. With Cre = 350 fF (typ.) and fT up to 450 MHz, the BFS20,235 exhibits low internal feedback. In properly laid-out common-emitter amplifiers with controlled impedances and short traces, neutralization is unnecessary below 150 MHz - confirmed by stability factor (K) > 1 in published application notes.
Can BFS20,235 replace BFS17 in existing designs?
Not directly. The BFS17 has VCEO = 25 V, fT = 650 MHz, and Cre = 250 fF - offering higher voltage, bandwidth, and lower feedback capacitance. Substituting BFS20,235 may reduce gain margin and stability at >200 MHz; redesign of bias and matching networks is required for functional equivalence.
BFS20,235 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 25 mA
- Voltage - Collector Emitter Breakdown (Max):
- 20 V
- Vce Saturation (Max) @ Ib, Ic:
- -
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 40 @ 7mA, 10V
- Power - Max:
- 250 mW
- Frequency - Transition:
- 450MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-236AB
BFS20,235 FAQ
1.How can I place an order for BFS20,235 through Aetrix?
Please submit a Request for Quotation (RFQ) for BFS20,235 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 BFS20,235 reliable?
The price and inventory of BFS20,235 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BFS20,235 is usually 5 days.
3.What payment methods are accepted for BFS20,235?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BFS20,235 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BFS20,235?
BFS20,235 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BFS20,235 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 BFS20,235?
For technical support, including BFS20,235 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BFS20,235 requirements.
6.How does Aetrix verify that BFS20,235 is sourced from the original manufacturer or authorized distributors?
All BFS20,235 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 BFS20,235 meets industry standards.
7.What is the process for return or replacement of BFS20,235?
All BFS20,235 units undergo pre-shipment inspection (PSI). If there is an issue with BFS20,235, 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 BFS20,235 part is unused and in its original packaging.
Return procedure for BFS20,235:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BFS20,235 Tags
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