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

Nexperia USA Inc. BF821-QVL

Name: BF821-QVL
Brand: Nexperia USA Inc.
SKU: BF821-QVL
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BF821-QVL

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

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

Datasheet:: BF821-QVL.pdf

Description:: TRANS PNP 300V 0.05A TO-236AB

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BF821-QVL from Nexperia is a PNP high-voltage bipolar junction transistor in SOT23 package, rated for −300 V V_CEO, −50 mA I_C, and 50 minimum h_FE at −25 mA/−20 V, designed for high-voltage switching in telephony line interface circuits.

For engineers reviewing the BF821-QVL datasheet, BF821-QVL pinout, BF821-QVL application, or BF821-QVL equivalent, key selection criteria include verified AEC-Q101 qualification, −300 V collector-emitter blocking capability, SOT23 thermal resistance (500 K/W), and complementary pairing with BF820-Q (NPN) and BF822-Q (NPN).

Technical Context

This discrete PNP transistor operates as a high-voltage switch in open-base configurations, supporting −300 V collector-emitter standoff and −300 V collector-base voltage under open-emitter conditions. Its DC current gain (h_FE ≥ 50) is specified at −25 mA and −20 V, with −800 mV V_CE(sat) at −30 mA/−5 mA drive.

Thermal performance is defined for PCB mounting with 1 cm² single-sided copper pad (R_th(j-a) = 500 K/W), and it exhibits low leakage: −10 nA I_CBO at −200 V/25 °C and −10 µA at 150 °C junction temperature.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−300 V: Maximum collector-emitter voltage with base open; enables use in 200 V telecom line feed circuits with safety margin.
I_C	−50 mA continuous: Rated collector current defines maximum steady-state switching load in relay drivers or protection stages.
h_FE	≥ 50 at −25 mA/−20 V: Confirmed DC current gain ensures reliable base drive sizing for linear or saturated switching operation.
V_CE(sat)	−800 mV at −30 mA/−5 mA: Low saturation voltage minimizes power loss and heating in high-side switch applications.
R_th(j-a)	500 K/W: Thermal resistance measured on standard 1 cm² copper pad; determines required board copper area for 150 °C max T_j.
f_T	60 MHz: Transition frequency supports moderate-speed switching up to ~10 MHz square-wave operation with acceptable gain roll-off.

Pinout & Package

SOT23 plastic surface-mount package (2.9 mm × 1.3 mm × 1.0 mm body, 1.9 mm lead pitch), with standardized 3-terminal layout and tin-plated copper mounting pad for collector thermal conduction.

Pin/Terminal	Circuit Role	Design Meaning
1	Base (B)	Control terminal for forward-biased PNP operation; requires negative bias relative to emitter to enable conduction.
2	Emitter (E)	Current source terminal; connected to higher potential rail in high-side switch configuration.
3	Collector (C)	Output terminal; carries switched load current and must be thermally coupled to PCB copper for power dissipation.

Key Features

Feature	Design Value
AEC-Q101 qualified	Stress-tested per automotive discrete semiconductor standard; validated for under-hood and infotainment power control.
−300 V V_CEO	Enables direct interface with legacy telephone line voltages (−48 V nominal, −170 V ring) plus safety margin.
Low I_CBO (−10 nA)	Minimizes off-state leakage in high-impedance bias networks and improves long-term reliability in standby modes.
SOT23 footprint compatibility	Matches JEDEC TO-236AB outline; supports automated placement and reflow soldering per IPC-7351B.

Applications

Telecom Line Interface

Automotive Power Switching

Use Scenario: Isolation and overvoltage protection in analog telephone line cards handling −48 V DC feed and −170 V AC ringing signals.

IC Role / Device Role / Timing Role: High-voltage PNP switch controlling feed current path and enabling polarity reversal during call setup.

Use Value: −300 V V_CEO provides 76 % headroom above peak ring voltage, reducing risk of breakdown during surge events.

Use Scenario: Load switching for interior lighting, HVAC actuators, or sensor biasing in 12 V/24 V vehicle systems.

IC Role / Device Role / Timing Role: Discrete high-side switch replacing integrated load switches where AEC-Q101 compliance and voltage margin are critical.

Use Value: AEC-Q101 qualification and −300 V rating allow reuse across 12 V, 24 V, and 48 V mild-hybrid architectures without redesign.

Industrial Signal Conditioning

High-Voltage Sensor Biasing

Use Scenario: Current sourcing for isolated 4–20 mA transmitter outputs in process automation equipment.

IC Role / Device Role / Timing Role: Precision current source element in op-amp feedback loop, leveraging stable h_FE and low V_CE(sat).

Use Value: 50 minimum h_FE and −800 mV V_CE(sat) ensure <1 % error contribution to loop accuracy at 20 mA full scale.

Use Scenario: Biasing photodiodes or avalanche photodetectors requiring stable reverse voltage up to −200 V.

IC Role / Device Role / Timing Role: High-impedance voltage clamp and current limiter in detector bias supply chain.

Use Value: −10 nA I_CBO at 25 °C prevents signal corruption in femtoamp-level photocurrent measurements.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage PNP transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BF822-Q	Same package and AEC-Q101 qualification; h_FE = 100–300 (vs. 50–200 for BF821-Q); lower V_CE(sat) (−600 mV typical).	Better suited for higher-gain, lower-loss linear regulation; less ideal for digital switching where gain tolerance matters less.	Select BF822-Q when tighter h_FE spread or reduced saturation loss is required; otherwise BF821-Q offers cost-effective baseline performance.
BC807-40	Lower V_CEO (−45 V), higher I_C (−500 mA), non-automotive grade; SOT23-compatible but not AEC-Q101 qualified.	Limited to non-safety-critical industrial or consumer applications; unsuitable for automotive or telecom primary protection.	Use only in cost-sensitive, low-voltage designs where −300 V rating and automotive qualification are unnecessary.

Compared with BF822-Q and BC807-40, BF821-Q uniquely balances −300 V capability, AEC-Q101 compliance, and SOT23 manufacturability-making it the only option among the three qualified for automotive telecom subsystems requiring both high voltage and reliability assurance.

Availability

BF821-QVL is available at Aetrix Electronics and suitable for telecom line interface, automotive power switching, and industrial signal conditioning requiring stable component supply across extended product lifecycles.

Supply support for BF821-QVL 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 semiconductor expert focused on high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified components and advanced packaging.

BF821-QVL belongs to Nexperia's AEC-Q101-qualified high-voltage bipolar transistor family, engineered specifically for robustness in telecom infrastructure and automotive power control where voltage margin and thermal stability are critical.

FAQ

Is BF821-QVL pin-compatible with BF820-Q or BF822-Q?

Yes-BF821-QVL shares identical SOT23 pinout (1=Base, 2=Emitter, 3=Collector) with BF820-Q and BF822-Q. All three are complementary PNP/NPN pairs with matching mechanical footprint and thermal pad layout, enabling direct substitution in layout-constrained designs without PCB revision.

What is the maximum allowable junction temperature during continuous operation?

The absolute maximum junction temperature is 150 °C, as defined in IEC 60134 limiting values. Continuous operation at this limit requires strict thermal design: R_th(j-a) = 500 K/W mandates ≤250 mW total power dissipation at ambient, achievable only with full 1 cm² copper pad and no additional thermal resistance.

Does BF821-QVL support wave soldering?

Yes-Nexperia provides dedicated wave soldering footprint data (Fig. 3) for SOT23, specifying 2.8 mm × 4.5 mm board area with 1.4 mm side clearances. The device is qualified for standard SnPb and lead-free wave processes when using recommended solder mask and pad geometry per datasheet Figure 3.

How does the −10 nA I_CBO specification impact high-impedance circuit design?

At −200 V V_CB and 25 °C, −10 nA collector-base leakage ensures minimal error in high-Z bias networks-for example, adding <0.2 mV offset across a 200 kΩ sense resistor. This enables accurate current-source design in 4–20 mA transmitters without active leakage compensation.

BF821-QVL 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:: PNP

Current - Collector (Ic) (Max):: 50 mA

Voltage - Collector Emitter Breakdown (Max):: 300 V

Vce Saturation (Max) @ Ib, Ic:: 800mV @ 5mA, 30mA

Current - Collector Cutoff (Max):: 10nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 50 @ 25mA, 20V

Power - Max:: 250 mW

Frequency - Transition:: 60MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: TO-236AB

BF821-QVL FAQ

1.How can I place an order for BF821-QVL through Aetrix?

Please submit a Request for Quotation (RFQ) for BF821-QVL 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 BF821-QVL reliable?

The price and inventory of BF821-QVL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BF821-QVL is usually 5 days.

3.What payment methods are accepted for BF821-QVL?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BF821-QVL transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BF821-QVL?

BF821-QVL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BF821-QVL 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 BF821-QVL?

For technical support, including BF821-QVL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BF821-QVL requirements.

6.How does Aetrix verify that BF821-QVL is sourced from the original manufacturer or authorized distributors?

All BF821-QVL 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 BF821-QVL meets industry standards.

7.What is the process for return or replacement of BF821-QVL?

All BF821-QVL units undergo pre-shipment inspection (PSI). If there is an issue with BF821-QVL, 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 BF821-QVL part is unused and in its original packaging.

Return procedure for BF821-QVL:

1.Submit a request within 90 days.

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

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