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

onsemi TN3440A

Name: TN3440A
Brand: onsemi
SKU: TN3440A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TN3440A

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA)

Datasheet:: TN3440A.pdf

Description:: TRANS NPN 250V 0.1A TO-226-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

TN3440A from Fairchild Semiconductor is an NPN general-purpose amplifier designed for horizontal driver, Class A off-line amplifier, and off-line switching applications. It features V_CEO = 250 V, I_C = 100 mA, f_T = 15 MHz, P_D = 1.0 W, and TO-226AE (TO-92) package with emitter-base-collector pinout.

For engineers reviewing the TN3440A datasheet, pinout, applications, or equivalent options, key selection criteria include high-voltage breakdown (V_CEO/V_CBO), thermal resistance (R_θJA = 50 °C/W), pulsed current gain behavior, saturation voltage at 50 mA, and suitability for line-synchronized switching stages.

Technical Context

The TN3440A is a silicon planar epitaxial NPN transistor fabricated in Fairchild's Process 36, optimized for stable high-voltage operation up to 250 V V_CEO and reliable Class A amplification with low C_obo (10 pF) and C_ibo (95 pF). Its f_T of 15 MHz supports mid-frequency horizontal deflection and auxiliary power switch control.

Thermal design is enabled by R_θJC = 125 °C/W and R_θJA = 50 °C/W, allowing operation from –55 °C to +150 °C junction temperature. Saturation performance is characterized at I_C = 50 mA / I_B = 4.0 mA, yielding V_CE(sat) ≤ 0.5 V and V_BE(sat) ≤ 1.3 V - critical for efficient switching in off-line topologies.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	250 V - supports direct connection to 220 VAC-derived rails with margin for transient spikes in horizontal driver circuits
I_C (continuous)	100 mA - sufficient for driving flyback transformer bases or small-signal stage loads without forced cooling
f_T	15 MHz - enables stable amplification and switching up to horizontal scan frequencies (~15.7 kHz) with bandwidth headroom
P_D @ 25°C	1.0 W - usable in compact TO-226AE packages with derating of 8 mW/°C above ambient
h_FE @ 2 mA	30–160 - wide DC gain range ensures predictable biasing across production lots in linear amplifier configurations
V_CE(sat)	≤ 0.5 V @ I_C = 50 mA, I_B = 4 mA - minimizes conduction loss in saturated-switch applications such as CRT deflection yoke drivers
R_θJA	50 °C/W - allows ~15 °C rise at 1 W dissipation on standard PCB land patterns, supporting thermally constrained designs

Pinout & Package

Package: TO-226AE (standard TO-92 variant, 3-lead, plastic, through-hole), dimensions per Fairchild Rev. A1 (October 1999), weight 0.300 g.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Connected to ground or low-side return path; defines reference for V_BE and sets emitter-follower output impedance
2 (Base)	Control input	Receives drive current to modulate collector current; requires external base resistor for current-limited turn-on in switching use
3 (Collector)	High-voltage output node	Handles up to 250 V with 100 mA continuous; connects to primary side of horizontal output transformer or snubber network

Key Features

Feature	Design Value
High V_CBO rating	300 V - provides robustness against inductive kickback in flyback and line-scan transformer drive
Low C_obo	10 pF @ V_CB = 10 V - reduces Miller effect and improves high-frequency stability in amplifier and switching configurations
Wide h_FE range	30–160 @ I_C = 2–20 mA - accommodates production variation while maintaining functional bias point in Class A stages
High-temperature operation	Junction range –55 °C to +150 °C - supports deployment in enclosed power supplies and CRT-based industrial displays
Process 36 fabrication	Fairchild's mature bipolar process - ensures consistent parametric yield and long-term reliability in legacy horizontal driver replacements

Applications

Horizontal Deflection Driver	Off-Line Class A Amplifier
Use Scenario: Driving the horizontal output transistor base in CRT television and monitor deflection circuits synchronized to 15.734 kHz line frequency. IC Role / Device Role / Timing Role: NPN amplifier providing current gain and level-shifting between low-voltage timing IC and high-voltage horizontal output stage. Use Value: V_CEO = 250 V and V_CBO = 300 V ensure safe operation under flyback voltage transients; f_T = 15 MHz guarantees faithful pulse reproduction without phase lag.	Use Scenario: Linear audio or signal amplification in AC-mains-powered equipment where isolation from ground-referenced inputs is required. IC Role / Device Role / Timing Role: Single-ended Class A amplifier stage with fixed emitter bias, delivering low-distortion gain without push-pull complexity. Use Value: h_FE ≥ 30 at 2 mA enables stable quiescent current setting; R_θJA = 50 °C/W permits operation on minimal copper area without heatsink.
Off-Line Switching Regulator	High-Voltage Sensor Interface
Use Scenario: Primary-side switch driver in low-power offline SMPS (<5 W), controlling MOSFET gate or optocoupler LED current. IC Role / Device Role / Timing Role: Saturated switch translating PWM controller output into high-current base drive for power devices. Use Value: V_CE(sat) ≤ 0.5 V at 50 mA limits power loss; I_C = 100 mA supports gate charge delivery for sub-1 A MOSFETs.	Use Scenario: Level-shifting interface between high-side voltage sense nodes (e.g., 200 V bus monitoring) and low-voltage ADC or comparator inputs. IC Role / Device Role / Timing Role: High-impedance emitter-follower buffer isolating measurement circuitry from high-voltage domains. Use Value: ICEO ≤ 50 µA at V_CE = 200 V ensures negligible leakage error; V_CEO(sus) = 250 V provides safety margin for overvoltage events.

Horizontal Deflection Driver

Off-Line Class A Amplifier

Use Scenario: Driving the horizontal output transistor base in CRT television and monitor deflection circuits synchronized to 15.734 kHz line frequency.

IC Role / Device Role / Timing Role: NPN amplifier providing current gain and level-shifting between low-voltage timing IC and high-voltage horizontal output stage.

Use Value: V_CEO = 250 V and V_CBO = 300 V ensure safe operation under flyback voltage transients; f_T = 15 MHz guarantees faithful pulse reproduction without phase lag.

Use Scenario: Linear audio or signal amplification in AC-mains-powered equipment where isolation from ground-referenced inputs is required.

IC Role / Device Role / Timing Role: Single-ended Class A amplifier stage with fixed emitter bias, delivering low-distortion gain without push-pull complexity.

Use Value: h_FE ≥ 30 at 2 mA enables stable quiescent current setting; R_θJA = 50 °C/W permits operation on minimal copper area without heatsink.

Off-Line Switching Regulator

High-Voltage Sensor Interface

Use Scenario: Primary-side switch driver in low-power offline SMPS (<5 W), controlling MOSFET gate or optocoupler LED current.

IC Role / Device Role / Timing Role: Saturated switch translating PWM controller output into high-current base drive for power devices.

Use Value: V_CE(sat) ≤ 0.5 V at 50 mA limits power loss; I_C = 100 mA supports gate charge delivery for sub-1 A MOSFETs.

Use Scenario: Level-shifting interface between high-side voltage sense nodes (e.g., 200 V bus monitoring) and low-voltage ADC or comparator inputs.

IC Role / Device Role / Timing Role: High-impedance emitter-follower buffer isolating measurement circuitry from high-voltage domains.

Use Value: ICEO ≤ 50 µA at V_CE = 200 V ensures negligible leakage error; V_CEO(sus) = 250 V provides safety margin for overvoltage events.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN high-voltage amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MPSA42	V_CEO = 300 V, I_C = 500 mA, f_T = 50 MHz, TO-92 package	Higher voltage and current rating; faster switching but higher C_ibo (12 pF) and lower h_FE min (25)	Preferred when >250 V standoff or >100 mA drive is needed; may require layout review due to higher f_T-induced instability risk
2N5551	V_CEO = 160 V, I_C = 600 mA, f_T = 100 MHz, TO-92 package	Lower V_CEO limits use to <160 V circuits; higher f_T and gain support RF preamp roles not intended for TN3440A	Suitable only in low-voltage Class A or switching applications where 250 V margin is unnecessary; not drop-in for horizontal driver replacement

Compared with MPSA42 and 2N5551, the TN3440A offers optimal balance of 250 V capability, 100 mA drive, and 15 MHz f_T for legacy CRT horizontal drivers and off-line amplifiers - neither over-specified nor under-rated for its target use cases.

Availability

TN3440A is available at Aetrix Electronics and suitable for horizontal deflection driver circuits, off-line Class A amplifier stages, and low-power off-line switching regulator designs requiring stable component supply and long-lifecycle support.

Supply support for TN3440A 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in analog, discrete, and power management ICs before its acquisition by ON Semiconductor in 2016.

The TN3440A belongs to Fairchild's general-purpose bipolar transistor family engineered for high-voltage linear and switching applications in consumer display and power conversion systems.

FAQ

What is the maximum collector-emitter voltage rating for the TN3440A?

The TN3440A has a maximum collector-emitter sustaining voltage V_CEO(sus) of 250 V at I_C = 50 mA and I_B = 0. This rating is confirmed in the Absolute Maximum Ratings table and verified in OFF CHARACTERISTICS under test condition V_CE = 200 V. The device is rated for operation in horizontal deflection circuits where flyback transients approach this limit.

Does the TN3440A support operation at elevated temperatures?

Yes, the TN3440A is specified for junction temperature operation from –55 °C to +150 °C. Its thermal resistance R_θJA is 50 °C/W, and derating begins above 25 °C at 8 mW/°C. These parameters are documented in the Thermal Characteristics section and validated across typical CRT and power supply environments.

What is the typical current gain (h_FE) of the TN3440A at different collector currents?

The TN3440A exhibits h_FE = 30–40 at I_C = 2.0 mA and h_FE = 40–160 at I_C = 20 mA, both measured at V_CE = 10 V and T_A = 25 °C. This wide range reflects process variation and supports flexible bias design in Class A amplifier implementations using the TN3440A.

Is the TN3440A pin-compatible with other TO-92 NPN transistors like the 2N3904?

No - the TN3440A uses TO-226AE (E-B-C pinout: Emitter=Pin1, Base=Pin2, Collector=Pin3), whereas the 2N3904 uses TO-92 (E-B-C pinout: Emitter=Pin1, Base=Pin2, Collector=Pin3) but differs electrically with V_CEO = 40 V and I_C = 200 mA. Physical compatibility does not imply functional interchangeability; the TN3440A is not a drop-in replacement for low-voltage general-purpose transistors.

What is the power dissipation capability of the TN3440A at room temperature?

The TN3440A has a total device dissipation P_D of 1.0 W at T_A = 25 °C, with linear derating of 8 mW/°C above that temperature. This value is specified in the Thermal Characteristics table and aligns with its use in compact TO-226AE packages without heatsinking in horizontal driver and Class A amplifier applications.

TN3440A Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA)

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

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

Voltage - Collector Emitter Breakdown (Max):: 250 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 4mA, 50mA

Current - Collector Cutoff (Max):: 50µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 40 @ 20mA, 10V

Power - Max:: 1 W

Frequency - Transition:: 15MHz

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-226-3

TN3440A FAQ

1.How can I place an order for TN3440A through Aetrix?

Please submit a Request for Quotation (RFQ) for TN3440A 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 TN3440A reliable?

The price and inventory of TN3440A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TN3440A is usually 5 days.

3.What payment methods are accepted for TN3440A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TN3440A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TN3440A?

TN3440A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TN3440A 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 TN3440A?

For technical support, including TN3440A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TN3440A requirements.

6.How does Aetrix verify that TN3440A is sourced from the original manufacturer or authorized distributors?

All TN3440A 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 TN3440A meets industry standards.

7.What is the process for return or replacement of TN3440A?

All TN3440A units undergo pre-shipment inspection (PSI). If there is an issue with TN3440A, 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 TN3440A part is unused and in its original packaging.

Return procedure for TN3440A:

1.Submit a request within 90 days.

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

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