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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > Single FETs, MOSFETs

NXP Semiconductors BF1211,215

Name: BF1211,215
Brand: NXP Semiconductors
SKU: BF1211,215
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BF1211,215

Manufacturer:: NXP Semiconductors

Category:: Single FETs, MOSFETs

Package:: TO-253-4, TO-253AA

Datasheet:: BF1211,215.pdf

Description:: RF MOSFET 5V SOT143B

Quantity:: RFQ Add To RFQ list

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Inventory:5,611

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Product details

Overview

BF1211 from NXP Semiconductors is an enhancement-type N-channel dual-gate MOSFET designed for low-noise, gain-controlled VHF/UHF amplification in 5 V TV tuner front-ends. It features 30 mS typical forward transfer admittance, 2.1 pF input capacitance at gate 1, 0.9 dB noise figure at 400 MHz, and operates with drain-source voltage up to 6 V and drain current up to 30 mA.

For engineers reviewing the BF1211 datasheet, BF1211 pinout, BF1211 application, or BF1211 equivalent, this page delivers verified electrical parameters, SOT143B package details, dual-gate biasing behavior, cross-modulation performance at 40 dB AGC, and direct alternatives for tuner amplifier redesigns.

Technical Context

The BF1211 uses a short-channel silicon structure with source and substrate internally connected, enabling high y_fs/C_ig1-ss ratio critical for wideband RF gain stability. Integrated protection diodes between each gate and source suppress ESD and input voltage surges without external clamping.

Its dual-gate architecture supports independent DC bias control: gate 2 (G2) sets quiescent operating point (typ. 4 V), while gate 1 (G1) accepts AGC voltage to linearly reduce gain-demonstrated by 10 dB gain reduction at ~1.8 V V_AGC and 105 dBμV cross-modulation level at 40 dB AGC.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS max	6 V - defines maximum supply rail compatibility with 5 V tuner systems
I_D max	30 mA - sets upper limit for quiescent current in low-power RF amplifier stages
\|y_fs\| typ	30 mS - determines small-signal transconductance and achievable gain per stage
C_ig1-ss typ	2.1 pF - impacts input matching network design and bandwidth limiting at UHF
F min	0.9 dB @ 400 MHz - specifies lowest achievable noise contribution in VHF/UHF LNA applications
Xmod @ 40 dB AGC	100–105 dBμV - quantifies immunity to two-tone intermodulation distortion under strong AGC control
T_j max	150 °C - establishes thermal derating boundary for surface-mount reliability on FR4 PCBs

Pinout & Package

BF1211 is housed in the SOT143B plastic surface-mounted package (4 leads), measuring 3.0 × 1.4 mm with 1.9 mm lead pitch. The package provides thermal resistance R_th(j-s) = 185 K/W to the soldering point of the source lead.

Pin	Circuit Role	Design Meaning
1	Source (S)	Common reference node; internally tied to substrate; primary current return path and thermal conduction path
2	Drain (D)	RF output node; connects to tuned load or next-stage input; carries full RF signal current
3	Gate 2 (G2)	DC bias control terminal; sets operating point (typically 4 V); decoupled from RF signal path
4	Gate 1 (G1)	AGC/control input; receives variable DC voltage to modulate gain; sensitive to leakage (I_G1-S ≤ 50 nA)

Key Features

Feature	Design Value
Internal source-substrate connection	Eliminates need for external substrate biasing; simplifies layout and improves repeatability in tuner modules
Integrated gate-source protection diodes	Enables robust operation against ESD and transient overvoltage without discrete clamp components
Partially self-biasing G1 circuit	Stabilizes DC operating point during AGC transitions, maintaining consistent cross-modulation performance
Low-frequency noise optimization	Supports analog TV channel reception where 1/f noise directly impacts picture clarity and snow artifacts
High y_fs/C_ig1-ss ratio	Delivers superior gain-bandwidth product for compact VHF/UHF amplifier designs with minimal external tuning

Applications

Digital TV Tuner Front-End	Analog TV Tuner Amplifier
Use Scenario: First-stage RF amplifier in terrestrial digital TV (DVB-T) tuners receiving signals from 47–862 MHz antenna inputs. IC Role / Device Role / Timing Role: Low-noise, AGC-controlled gain block that maintains SNR across varying signal strengths while rejecting adjacent-channel interference. Use Value: 0.9 dB noise figure at 400 MHz and 105 dBμV cross-modulation threshold ensure reliable QAM-64/256 demodulation under weak-signal and multi-path conditions.	Use Scenario: RF preamplifier in legacy NTSC/PAL broadcast receivers operating in VHF-L (47–108 MHz) and UHF (470–862 MHz) bands. IC Role / Device Role / Timing Role: Dual-gate gain-control element enabling automatic contrast/brightness stabilization via AGC voltage applied to G1. Use Value: Stable 11–19 mA I_DSX across temperature and process variation ensures consistent video signal amplitude and reduced ghosting artifacts.
CATV Set-Top Box LNA	FM Radio Front-End
Use Scenario: Input amplifier in cable TV set-top boxes handling 54–1002 MHz downstream signals with upstream noise isolation requirements. IC Role / Device Role / Timing Role: High-linearity, low-noise active filter stage suppressing ingress noise while preserving composite quadrature amplitude modulation fidelity. Use Value: 29 dB power gain at 400 MHz and 15–30 fF C_r_ss minimize Miller effect, enabling clean channel selection without image rejection filters.	Use Scenario: RF amplifier in portable FM radio receivers covering 76–108 MHz band with battery-powered 5 V supply constraints. IC Role / Device Role / Timing Role: Single-supply, low-I_Q gain block optimized for 30 mA max drain current and 180 mW total dissipation. Use Value: 3.5 dB noise figure at 11 MHz and 2.6 pF C_ig1-ss support high-selectivity ceramic filter matching and extended battery life.

Digital TV Tuner Front-End

Analog TV Tuner Amplifier

Use Scenario: First-stage RF amplifier in terrestrial digital TV (DVB-T) tuners receiving signals from 47–862 MHz antenna inputs.

IC Role / Device Role / Timing Role: Low-noise, AGC-controlled gain block that maintains SNR across varying signal strengths while rejecting adjacent-channel interference.

Use Value: 0.9 dB noise figure at 400 MHz and 105 dBμV cross-modulation threshold ensure reliable QAM-64/256 demodulation under weak-signal and multi-path conditions.

Use Scenario: RF preamplifier in legacy NTSC/PAL broadcast receivers operating in VHF-L (47–108 MHz) and UHF (470–862 MHz) bands.

IC Role / Device Role / Timing Role: Dual-gate gain-control element enabling automatic contrast/brightness stabilization via AGC voltage applied to G1.

Use Value: Stable 11–19 mA I_DSX across temperature and process variation ensures consistent video signal amplitude and reduced ghosting artifacts.

CATV Set-Top Box LNA

FM Radio Front-End

Use Scenario: Input amplifier in cable TV set-top boxes handling 54–1002 MHz downstream signals with upstream noise isolation requirements.

IC Role / Device Role / Timing Role: High-linearity, low-noise active filter stage suppressing ingress noise while preserving composite quadrature amplitude modulation fidelity.

Use Value: 29 dB power gain at 400 MHz and 15–30 fF C_r_ss minimize Miller effect, enabling clean channel selection without image rejection filters.

Use Scenario: RF amplifier in portable FM radio receivers covering 76–108 MHz band with battery-powered 5 V supply constraints.

IC Role / Device Role / Timing Role: Single-supply, low-I_Q gain block optimized for 30 mA max drain current and 180 mW total dissipation.

Use Value: 3.5 dB noise figure at 11 MHz and 2.6 pF C_ig1-ss support high-selectivity ceramic filter matching and extended battery life.

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
BF1212	Same SOT143B package; higher \|y_fs\| (35 mS typ) but elevated noise figure (1.2 dB @ 400 MHz)	Better gain margin in weak-signal VHF, but reduced SNR headroom in dense urban multipath environments	Select when system-level gain budget exceeds 20 dB and noise floor is dominated by later stages
BF998	SOT343 package; lower C_ig1-ss (1.7 pF) and improved F_min (0.7 dB @ 400 MHz), but requires different PCB footprint	Superior UHF noise performance and tighter input matching, yet incompatible pinout and thermal profile	Choose for new designs targeting <0.8 dB NF at 800 MHz; not suitable for drop-in BF1211 replacement

Compared with BF1211, BF1212 trades 0.3 dB higher noise for +5 mS transconductance-beneficial in cascaded gain chains-while BF998 offers best-in-class noise but demands layout revision and thermal revalidation due to SOT343's lower R_th(j-s) (155 K/W).

Availability

BF1211 is available at Aetrix Electronics and suitable for digital TV tuners, analog broadcast receivers, CATV set-top boxes, and portable FM radio front-ends requiring stable component supply across long-lifecycle consumer electronics programs.

Supply support for BF1211 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 specializing in high-performance RF, analog, and mixed-signal solutions for consumer, automotive, and industrial markets.

The BF1211 belongs to NXP's legacy dual-gate MOSFET product line engineered specifically for low-voltage, low-noise VHF/UHF amplifier applications in broadcast receiver systems.

FAQ

What is the maximum drain-source voltage rating for BF1211?

The BF1211 has a maximum drain-source voltage (V_DS) rating of 6 V, as specified in the Absolute Maximum Ratings table. This allows safe operation with standard 5 V supply rails used in TV tuner applications. Exceeding this voltage risks permanent breakdown of the channel, especially under transient conditions. The BF1211 datasheet confirms V_(BR)DSS ≥ 6 V at I_D = 10 μA, validating its suitability for 5 V systems with margin.

Does BF1211 require external gate protection diodes?

No, BF1211 does not require external gate protection diodes. The device integrates internal diodes between each gate (G1 and G2) and the source terminal to suppress ESD and input voltage surges. This is explicitly stated in the "DESCRIPTION" section of the datasheet and confirmed in the "FEATURES" list. These built-in diodes eliminate the need for discrete clamps in tuner front-end designs, reducing component count and board space.

What is the typical noise figure of BF1211 at 400 MHz?

The typical noise figure (F) of BF1211 at 400 MHz is 0.9 dB, with a maximum of 1.6 dB, measured under conditions of Y_S = Y_S(opt), V_DS = 5 V, and I_D = 15 mA. This value is documented in both the Quick Reference Data and Dynamic Characteristics sections. The low noise figure makes BF1211 suitable for first-stage amplification in VHF/UHF tuners where minimizing system noise temperature is critical.

How is cross-modulation performance specified for BF1211?

BF1211 cross-modulation (Xmod) is specified as 100–105 dBμV at 40 dB AGC, measured using a two-tone test with f_w = 50 MHz and f_unw = 60 MHz. This parameter appears in both the Quick Reference Data and Dynamic Characteristics tables. It reflects the input signal level at which 1% intermodulation distortion occurs under deep AGC control-directly indicating linearity retention during strong-signal reception in TV tuners.

What package type is used for BF1211?

BF1211 is packaged in the SOT143B plastic surface-mounted package, a 4-lead outline with standard pinning (Pin 1 = Source, Pin 2 = Drain, Pin 3 = Gate 2, Pin 4 = Gate 1). This is confirmed in the ORDERING INFORMATION table and illustrated in Figure 1 of the datasheet. The SOT143B measures 3.0 × 1.4 mm and provides R_th(j-s) = 185 K/W, distinguishing it from the BF1211R (SOT143R) and BF1211WR (SOT343R) variants.

BF1211,215 Specifications

Product attributes: Attribute value

Manufacturer:: NXP Semiconductors

Series:: -

Package/Case:: TO-253-4, TO-253AA

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Technology:: MOSFET (Metal Oxide)

Configuration:: N-Channel Dual Gate

Frequency:: 400MHz

Gain:: 29dB

Voltage - Test:: 5 V

Current Rating (Amps):: 30mA

Noise Figure:: 0.9dB

Current - Test:: 15 mA

Power - Output:: -

Voltage - Rated:: 6 V

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-143B

BF1211,215 FAQ

1.How can I place an order for BF1211,215 through Aetrix?

Please submit a Request for Quotation (RFQ) for BF1211,215 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 BF1211,215 reliable?

The price and inventory of BF1211,215 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BF1211,215 is usually 5 days.

3.What payment methods are accepted for BF1211,215?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BF1211,215 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BF1211,215?

BF1211,215 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BF1211,215 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 BF1211,215?

For technical support, including BF1211,215 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BF1211,215 requirements.

6.How does Aetrix verify that BF1211,215 is sourced from the original manufacturer or authorized distributors?

All BF1211,215 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 BF1211,215 meets industry standards.

7.What is the process for return or replacement of BF1211,215?

All BF1211,215 units undergo pre-shipment inspection (PSI). If there is an issue with BF1211,215, 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 BF1211,215 part is unused and in its original packaging.

Return procedure for BF1211,215:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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