Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Bipolar RF Transistors

NXP Semiconductors BFG31,115

Name: BFG31,115
Brand: NXP Semiconductors
SKU: BFG31,115
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BFG31,115

Manufacturer:: NXP Semiconductors

Category:: Bipolar RF Transistors

Package:: TO-261-4, TO-261AA

Datasheet:: BFG31,115.pdf

Description:: RF TRANS PNP 15V 5GHZ SOT223

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,208

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

BFG31,115 from NXP Semiconductors is a PNP planar epitaxial wideband transistor in SOT223 package, rated for 5 GHz transition frequency (f_T = 5.0 GHz), −15 V collector-emitter breakdown voltage (V_(BR)CEO = −18 V), and 600 mV output voltage into 75 Ω at 850 MHz - designed for RF amplifier stages in CATV line drivers and broadband signal distribution systems.

For engineers reviewing the BFG31,115 datasheet, BFG31,115 pinout, BFG31,115 application, or BFG31,115 equivalent, this discrete PNP RF transistor requires attention to emitter-common configuration, thermal derating above 135 °C solder point temperature, DC bias stability at −70 mA collector current, and unilateral gain optimization at 500–800 MHz bands.

Technical Context

The BFG31,115 operates as a high-frequency PNP amplifier with gold-metallized emitter-base-collector junctions ensuring reliability under sustained RF stress. Its SOT223 package integrates a thermally enhanced collector tab (R_{th j-s} = 40 K/W) and supports DC bias at V_CE = −10 V and I_C = −70 mA for stable small-signal gain.

It delivers 12 dB maximum unilateral power gain (G_UM) at 800 MHz and 16 dB at 500 MHz under identical bias conditions, with feedback capacitance (C_re) of 1.6 pF and collector-base capacitance (C_cb) of 1.8 pF - enabling predictable matching network design for 450–860 MHz intermodulation-critical applications.

Key Specifications

Parameter	Value and Actual Design Meaning
f_T	5.0 GHz typical - defines usable small-signal amplification bandwidth up to UHF band without gain roll-off.
G_UM	12 dB at 800 MHz - sets achievable single-tone power gain before matching network insertion loss.
V_(BR)CEO	−18 V minimum - determines maximum allowable collector swing in emitter-follower or common-emitter configurations.
V_O	600 mV typical into 75 Ω - specifies linear output voltage capability for CATV signal integrity at DIN-compliant distortion levels.
R_{th j-s}	40 K/W - quantifies thermal resistance from junction to solder point, guiding heatsink requirements for 1 W P_tot operation.
C_re	1.6 pF - directly impacts stability factor (k) and neutralization needs in broadband amplifier layouts.
h_FE	25 minimum at −70 mA / −10 V - ensures sufficient DC current drive for bias network design margin.

Pinout & Package

Package: SOT223 plastic surface-mounted package with integrated collector tab for thermal dissipation; 4-lead outline per JEDEC SC-73 standard, footprint compatible with PCB thermal pad anchoring.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Primary current sink node; dual emitter terminals (1 and 3) enable low-inductance parallel connection in high-current RF paths.
2	Base	Control input requiring stable negative bias relative to emitter; low C_eb (5 pF) eases impedance matching at UHF.
3	Emitter	Second emitter terminal - electrically identical to Pin 1; used for symmetrical layout or current sharing.
4	Collector	High-current output node with thermal tab; must be soldered to copper pour for R_{th j-s} compliance and 1 W power handling.

Key Features

Feature	Design Value
Gold metallization	Prevents electromigration and intermetallic degradation during long-term RF operation at elevated junction temperatures.
5 GHz f_T	Enables linear amplification across full CATV downstream band (54–860 MHz) with headroom for harmonic suppression.
12 dB G_UM @ 800 MHz	Supports ≥10 dB net gain after PCB trace loss and filter insertion loss in 75 Ω distributed video systems.
600 mV V_O into 75 Ω	Meets DIN 45004B −60 dB intermodulation threshold for analog cable TV signal fidelity at 850 MHz.
SOT223 thermal design	Allows 1 W continuous dissipation with Ts ≤ 135 °C when mounted on ≥1 cm² 2-oz copper, eliminating need for external heatsinks.

Applications

CATV Line Driver	UHF Broadband Amplifier
Use Scenario: Amplifying downstream RF signals in coaxial distribution networks from headend to subscriber drop points. IC Role / Device Role / Timing Role: PNP wideband voltage amplifier operating in Class A with emitter degeneration for linearity. Use Value: Delivers 600 mV output into 75 Ω while maintaining −60 dBc intermodulation distortion at 850 MHz, meeting DIN 45004B broadcast standards.	Use Scenario: Boosting weak UHF signals in terrestrial TV tuners and spectrum analyzers before ADC sampling. IC Role / Device Role / Timing Role: Small-signal RF gain block with fixed −10 V collector-emitter bias and matched 50 Ω input/output. Use Value: Provides 16 dB unilateral gain at 500 MHz and 12 dB at 800 MHz, enabling >10 dB SNR improvement before baseband processing.
RF Test Equipment Front-End	Video Signal Distribution Hub
Use Scenario: Low-noise pre-amplification stage in portable RF signal generators and vector network analyzers. IC Role / Device Role / Timing Role: High-linearity PNP transistor configured as common-emitter amplifier with stabilized DC bias. Use Value: Achieves <−65 dBc second-order IMD at 450 MHz with 50 dBmV output, supporting accurate stimulus-response measurement.	Use Scenario: Re-amplifying composite video signals across multi-room AV distribution systems with minimal group delay variation. IC Role / Device Role / Timing Role: Wideband voltage buffer with 75 Ω source/load termination and low C_re-induced phase shift. Use Value: Maintains <0.5° group delay deviation from 50–800 MHz, preserving sync pulse integrity in SD/HD video transmission.

CATV Line Driver

UHF Broadband Amplifier

Use Scenario: Amplifying downstream RF signals in coaxial distribution networks from headend to subscriber drop points.

IC Role / Device Role / Timing Role: PNP wideband voltage amplifier operating in Class A with emitter degeneration for linearity.

Use Value: Delivers 600 mV output into 75 Ω while maintaining −60 dBc intermodulation distortion at 850 MHz, meeting DIN 45004B broadcast standards.

Use Scenario: Boosting weak UHF signals in terrestrial TV tuners and spectrum analyzers before ADC sampling.

IC Role / Device Role / Timing Role: Small-signal RF gain block with fixed −10 V collector-emitter bias and matched 50 Ω input/output.

Use Value: Provides 16 dB unilateral gain at 500 MHz and 12 dB at 800 MHz, enabling >10 dB SNR improvement before baseband processing.

RF Test Equipment Front-End

Video Signal Distribution Hub

Use Scenario: Low-noise pre-amplification stage in portable RF signal generators and vector network analyzers.

IC Role / Device Role / Timing Role: High-linearity PNP transistor configured as common-emitter amplifier with stabilized DC bias.

Use Value: Achieves <−65 dBc second-order IMD at 450 MHz with 50 dBmV output, supporting accurate stimulus-response measurement.

Use Scenario: Re-amplifying composite video signals across multi-room AV distribution systems with minimal group delay variation.

IC Role / Device Role / Timing Role: Wideband voltage buffer with 75 Ω source/load termination and low C_re-induced phase shift.

Use Value: Maintains <0.5° group delay deviation from 50–800 MHz, preserving sync pulse integrity in SD/HD video transmission.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP wideband amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BFG97	NPN complement with symmetric f_T (5 GHz), but requires positive supply and inverted bias network topology.	Used where NPN-based amplifier architectures dominate; not interchangeable without circuit redesign.	Select BFG97 only when redesigning for NPN biasing and polarity-consistent signal flow.
MRF947	Higher P_tot (1.5 W), higher f_T (6 GHz), but TO-92 package lacks integrated thermal tab and requires external heatsinking.	Suitable for higher-power lab-grade amplifiers; incompatible with SOT223 footprint and automated assembly.	Choose MRF947 only when >1 W RF output and 6 GHz bandwidth are required, accepting manual assembly and thermal management overhead.

Compared with BFG97 and MRF947, the BFG31,115 uniquely combines SOT223 thermal integration, PNP polarity for negative-rail systems, and verified −60 dBc IMD performance at 850 MHz - making it optimal for cost-sensitive, high-volume CATV line driver designs requiring no PCB rework.

Availability

BFG31,115 is available at Aetrix Electronics and suitable for CATV infrastructure, UHF test equipment, and video distribution systems requiring stable component supply, consistent parametric binning, and long-term obsolescence mitigation.

Supply support for BFG31,115 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 interface solutions for communications, automotive, and industrial markets.

The BFG31,115 belongs to NXP's legacy RF transistor product line engineered specifically for broadband analog signal amplification in cable television and UHF instrumentation applications.

FAQ

What is the maximum collector-emitter voltage rating for the BFG31,115?

The BFG31,115 has a guaranteed minimum collector-emitter breakdown voltage V_(BR)CEO of −18 V under open-base conditions at I_C = −10 mA. Its absolute maximum rated V_CEO is −15 V, meaning the device must not be operated beyond this voltage in normal use to prevent permanent damage. This rating directly constrains the supply rail selection in common-emitter amplifier designs using the BFG31,115.

Does the BFG31,115 require external neutralization for stable wideband operation?

Yes - the BFG31,115 exhibits 1.6 pF feedback capacitance (C_re) which can cause instability in high-gain configurations above 500 MHz. Stable operation typically requires either emitter degeneration, resistive base damping, or narrowband neutralization using a capacitor from collector to base. The BFG31,115 datasheet provides measured S-parameter data to support such network design, confirming its need for careful layout and stabilization.

Can the BFG31,115 be used in surface-mount reflow processes?

Yes - the BFG31,115 is qualified for lead-free reflow soldering per J-STD-020. Its SOT223 package withstands peak temperatures up to 260 °C for 10 seconds. However, the collector tab (Pin 4) must be fully soldered to a thermal pad to maintain R_{th j-s} = 40 K/W and avoid junction overheating during operation. Incomplete tab wetting will degrade thermal performance and reduce safe operating area.

What is the typical intermodulation distortion performance of the BFG31,115 at 850 MHz?

At 850 MHz, the BFG31,115 achieves −60 dBc third-order intermodulation distortion (d_im) when biased at I_C = −70 mA, V_CE = −10 V, and delivering 600 mV output into 75 Ω - matching DIN 45004B broadcast linearity requirements. This performance is validated in Figure 7 of the official datasheet and confirms suitability for analog CATV signal distribution where spectral purity is critical.

Is the BFG31,115 pin-compatible with any modern NXP RF transistors?

No - the BFG31,115 is a legacy device with no direct pin-compatible replacement in NXP's current portfolio. While newer RF transistors like the BFU760F offer improved noise figure and gain, they use SOT343 or SOT89 packages and differ in pin assignment, bias requirements, and thermal design. Migration from the BFG31,115 requires full schematic and layout revision, not drop-in substitution.

BFG31,115 Specifications

Product attributes: Attribute value

Manufacturer:: NXP Semiconductors

Series:: -

Package/Case:: TO-261-4, TO-261AA

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: PNP

Voltage - Collector Emitter Breakdown (Max):: 15V

Frequency - Transition:: 5GHz

Noise Figure (dB Typ @ f):: -

Gain:: -

Power - Max:: 1W

DC Current Gain (hFE) (Min) @ Ic, Vce:: 25 @ 70mA, 10V

Current - Collector (Ic) (Max):: 100mA

Operating Temperature:: 175°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SC-73

BFG31,115 FAQ

1.How can I place an order for BFG31,115 through Aetrix?

Please submit a Request for Quotation (RFQ) for BFG31,115 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 BFG31,115 reliable?

The price and inventory of BFG31,115 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BFG31,115 is usually 5 days.

3.What payment methods are accepted for BFG31,115?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BFG31,115 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BFG31,115?

BFG31,115 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BFG31,115 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 BFG31,115?

For technical support, including BFG31,115 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BFG31,115 requirements.

6.How does Aetrix verify that BFG31,115 is sourced from the original manufacturer or authorized distributors?

All BFG31,115 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 BFG31,115 meets industry standards.

7.What is the process for return or replacement of BFG31,115?

All BFG31,115 units undergo pre-shipment inspection (PSI). If there is an issue with BFG31,115, 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 BFG31,115 part is unused and in its original packaging.

Return procedure for BFG31,115:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-03 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-01 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…