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

Nexperia USA Inc. BF840,215

Name: BF840,215
Brand: Nexperia USA Inc.
SKU: BF840,215
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BF840,215

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: BF840,215.pdf

Description:: TRANS NPN 40V 0.025A TO-236AB

Quantity:: RFQ Add To RFQ list

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Inventory:8,823

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Product details

Overview

BF840,215 from Nexperia is an NPN medium-frequency transistor in SOT23 package, rated for V_CEO = 40 V, I_C = 25 mA DC, f_T = 380 MHz, and P_tot = 250 mW at T_amb ≤ 25 °C. It serves as a low-current, low-voltage active device in AM/FM receiver IF amplifiers and mixer stages.

For engineers reviewing the BF840,215 datasheet, BF840,215 pinout, BF840,215 application, or BF840,215 equivalent, key selection factors include its 380 MHz transition frequency, 67–222 h_FE range at 1 mA/10 V, 0.3 pF feedback capacitance, SOT23 thermal resistance of 500 K/W, and suitability for compact AM mixer designs requiring stable gain below 100 MHz.

Technical Context

The BF840,215 operates as a general-purpose NPN RF transistor optimized for medium-frequency analog signal amplification. Its design targets low-noise, low-power operation with defined h_FE spread (67–222), tight V_BE (675–775 mV), and minimal Cre (≤0.3 pF) to support stable small-signal gain in tuned circuits.

It is characterized under standard conditions: T_j = 25 °C, V_CE = 10 V, I_C = 1 mA. The device exhibits low leakage (ICBO ≤ 100 nA at V_CB = 20 V) and operates across −65 °C to +150 °C ambient, with junction temperature limited to 150 °C.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum collector-emitter voltage before breakdown; defines safe operating range in AM/FM IF amplifier biasing.
I_C (DC)	25 mA - Continuous collector current limit; sets upper bound for quiescent bias in low-power mixer stages.
f_T	380 MHz - Transition frequency; enables usable gain up to ~100 MHz IF bands in AM receivers.
h_FE	67–222 - DC current gain range at 1 mA/10 V; impacts stage gain consistency and bias stability in production.
Cre	≤0.3 pF - Feedback capacitance at 10 V V_CB; minimizes unwanted coupling in tuned amplifier designs.
P_tot	250 mW - Total power dissipation on FR4 PCB; determines thermal margin in space-constrained SOT23 layouts.
R_th(j-a)	500 K/W - Junction-to-ambient thermal resistance; informs derating above 25 °C ambient in sealed enclosures.

Pinout & Package

SOT23 plastic surface-mounted package (TO-236AB), 3-lead, dimensions per JEDEC MO-215: 2.9 × 1.3 × 1.0 mm (L × W × H), with 0.95 mm lead pitch.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control terminal for forward-active bias; requires stable 675–775 mV V_BE drop at 1 mA.
2	Emiter	Current source terminal; grounded in common-base mixer configurations or AC-coupled in IF amps.
3	Collector	Output terminal; connected to tuned LC load or IF transformer secondary in AM receiver front-end stages.

Key Features

Feature	Design Value
Medium-frequency optimization	380 MHz f_T supports stable gain in 455 kHz–10.7 MHz IF bands without oscillation risk.
Low feedback capacitance	≤0.3 pF Cre reduces Miller effect, enabling higher input impedance in common-emitter IF amplifiers.
Controlled h_FE spread	67–222 range allows predictable DC bias design while accommodating process variation in volume production.
SOT23 thermal performance	500 K/W R_th(j-a) enables operation up to +85 °C ambient without forced cooling in consumer-grade receivers.

Applications

AM Mixer Stage

IF Amplifier (AM)

Use Scenario: Local oscillator and RF signal mixing in portable AM radios to generate 455 kHz intermediate frequency.

IC Role / Device Role / Timing Role: NPN transistor operating in forward-active mode as a passive mixer core with external diodes or as active switching mixer.

Use Value: Low Cre (≤0.3 pF) and 380 MHz f_T ensure minimal LO feedthrough and adequate conversion gain at 1 MHz RF inputs.

Use Scenario: Single-stage 455 kHz bandpass amplification following mixer output in battery-powered AM receivers.

IC Role / Device Role / Timing Role: Common-emitter amplifier biased at 1 mA for linear small-signal gain with tuned collector load.

Use Value: 67–222 h_FE and 25 mA I_C rating allow robust gain control across temperature and unit-to-unit variation.

FM IF Amplifier

Portable Radio Front-End

Use Scenario: First IF amplification stage at 10.7 MHz in compact FM radio modules with ceramic filter coupling.

IC Role / Device Role / Timing Role: Medium-frequency NPN amplifier with emitter degeneration for gain flatness and distortion control.

Use Value: 40 V V_CEO headroom accommodates supply ripple in unregulated 3 V–6 V battery systems without saturation.

Use Scenario: Signal conditioning in ultra-low-cost portable radios where board space and BOM count are critical.

IC Role / Device Role / Timing Role: General-purpose RF transistor replacing higher-cost alternatives in non-automotive consumer audio front-ends.

Use Value: SOT23 footprint and 250 mW P_tot enable direct replacement of older TO-92 transistors without layout redesign.

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	Higher h_FE (200–450), lower f_T (300 MHz), same SOT23 package and V_CEO/I_C ratings.	Better DC gain uniformity but reduced high-frequency response; less suitable above 50 MHz.	Prefer for DC-coupled IF amps needing tighter h_FE control; avoid in >100 MHz mixer designs.
MMBT3904LT1G	Higher f_T (300 MHz typical, up to 400 MHz), wider h_FE spread (100–300), same 40 V/200 mA ratings but higher P_tot (310 mW).	Higher power handling and broader gain bandwidth, but Cre = 4 pF limits stability in narrowband tuned circuits.	Prefer when higher output drive or thermal margin is needed; verify Cre impact in 455 kHz LC tank designs.

Compared with BC847B,215 and MMBT3904LT1G, the BF840,215 offers the lowest Cre (≤0.3 pF) and highest guaranteed f_T (380 MHz), making it uniquely suited for stable, low-distortion AM mixer and narrowband IF amplifier applications where capacitive feedback must be minimized.

Availability

BF840,215 is available at Aetrix Electronics and suitable for AM mixer stages, IF amplifiers in AM/FM receivers, and portable radio front-end designs requiring stable component supply and long-term obsolescence management.

Supply support for BF840,215 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 BF840,215 belongs to Nexperia's legacy RF transistor product line, designed specifically for cost-sensitive, medium-frequency analog signal processing in consumer radio equipment.

FAQ

Is BF840,215 RoHS compliant and halogen-free?

Yes. BF840,215 meets RoHS Directive 2011/65/EU and is halogen-free per Nexperia standard specifications. The SOT23 package uses lead-free solderable terminations and complies with JEDEC J-STD-020 moisture sensitivity level 1 (MSL1) for unlimited floor life at ≤30 °C/85% RH.

What is the maximum recommended operating frequency for BF840,215 in amplifier configurations?

The BF840,215 is characterized with f_T = 380 MHz, but practical small-signal amplifier use is validated up to 100 MHz. At 455 kHz and 10.7 MHz IF frequencies, it delivers stable gain with minimal phase shift and distortion due to its low Cre and controlled h_FE spread.

Can BF840,215 replace BF199 or BF240 in existing AM radio designs?

Yes, with minor bias adjustment. BF840,215 shares identical SOT23 pinout and similar V_CEO/I_C ratings with BF199 (40 V/25 mA) and BF240 (30 V/30 mA). Its higher f_T and lower Cre improve high-frequency stability, though V_EB max (4 V) is identical-no circuit modification is required beyond verifying quiescent current.

Does BF840,215 require heatsinking in standard FR4 PCB layouts?

No. With P_tot = 250 mW and R_th(j-a) = 500 K/W on FR4, junction temperature rise is ≤125 K at full power-well within the 150 °C T_j limit at 25 °C ambient. Heatsinking is unnecessary unless ambient exceeds 85 °C or continuous I_C > 15 mA is used in sealed enclosures.

BF840,215 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):: 40 V

Vce Saturation (Max) @ Ib, Ic:: -

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 67 @ 1mA, 10V

Power - Max:: 250 mW

Frequency - Transition:: 380MHz

Operating Temperature:: 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: TO-236AB

BF840,215 FAQ

1.How can I place an order for BF840,215 through Aetrix?

Please submit a Request for Quotation (RFQ) for BF840,215 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 BF840,215 reliable?

The price and inventory of BF840,215 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BF840,215 is usually 5 days.

3.What payment methods are accepted for BF840,215?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BF840,215 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BF840,215?

BF840,215 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BF840,215 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 BF840,215?

For technical support, including BF840,215 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BF840,215 requirements.

6.How does Aetrix verify that BF840,215 is sourced from the original manufacturer or authorized distributors?

All BF840,215 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 BF840,215 meets industry standards.

7.What is the process for return or replacement of BF840,215?

All BF840,215 units undergo pre-shipment inspection (PSI). If there is an issue with BF840,215, 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 BF840,215 part is unused and in its original packaging.

Return procedure for BF840,215:

1.Submit a request within 90 days.

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

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