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

onsemi NJL21194DG

Name: NJL21194DG
Brand: onsemi
SKU: NJL21194DG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: NJL21194DG

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-264-5

Datasheet:: NJL21194DG.pdf

Description:: TRANS NPN 250V 16A TO-264

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Product details

Overview

NJL21194DG from onsemi is an NPN bipolar power transistor in the ThermalTrak™ family, designed for high-fidelity audio amplifier output stages. It delivers 16 A continuous collector current, 250 V V_CEO, and 200 W power dissipation at T_C = 25°C, with integrated thermally matched bias diode for real-time thermal tracking in Class AB amplifiers.

For engineers reviewing the NJL21194DG datasheet, pinout, applications, or equivalent options, this device is selected for high-reliability, low-distortion audio power output where bias stability across temperature swings and extended safe operating area are critical design requirements.

Technical Context

The NJL21194DG integrates a monolithically matched bias diode on the same silicon die as the power transistor, enabling instantaneous thermal coupling without lag. Its SOA is defined up to 1 s pulse width with V_CE = 50 V (I_S/b = 4.0 A) and V_CE = 80 V (I_S/b = 2.25 A), supporting robust transient handling in audio output stages.

It operates as a medium-frequency device (f_T = 4 MHz) with h_FE = 25–75 at I_C = 8–16 A, V_CE = 5 V, and exhibits low V_CE(sat) (1.4 V @ 8 A/0.8 A, 4 V @ 16 A/3.2 A), optimized for linear amplification rather than switching.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	250 V - Maximum collector-emitter voltage before breakdown under open-base conditions; defines rail voltage limit in audio output stage design.
I_C (continuous)	16 A - Sustained collector current capability at T_C = 25°C; supports ≥100 W RMS audio output into 4 Ω loads.
P_D @ T_C = 25°C	200 W - Total power dissipation limit at case temperature 25°C; requires heatsink with R_JC ≤ 0.625°C/W for thermal safety.
h_FE	25–75 - DC current gain range at I_C = 8–16 A, V_CE = 5 V; enables stable bias network design with predictable base drive requirements.
f_T	4 MHz - Current gain bandwidth product at I_C = 1 A, V_CE = 10 V; sufficient for full-audio-band linear amplification with margin.
R_JC	0.625°C/W - Junction-to-case thermal resistance; determines minimum heatsink thermal resistance needed to maintain T_J ≤ 150°C.

Pinout & Package

Package: TO-264 (Case 340AA), 5-lead, Pb-free, with integral thermal pad. Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector, Pin 4 = Anode (bias diode), Pin 5 = Cathode (bias diode).

Pin/Terminal	Circuit Role	Design Meaning
1 - Base	Control input for transistor conduction	Receives base current to drive 16 A collector current; requires stable bias network referencing matched diode terminals.
2 - Emitter	Emitter terminal of NPN power transistor	Common reference node for output stage; electrically isolated from bias diode cathode (Pin 5) per schematic.
3 - Collector	High-current output terminal	Connects to speaker load or output transformer primary; rated for 250 V and 16 A continuous operation.
4 - Anode	Anode of integrated bias diode	Connected to base of complementary PNP (NJL21193DG) in push-pull pair; enables matched thermal tracking.
5 - Cathode	Cathode of integrated bias diode	Connected to emitter of NJL21193DG; completes thermally coupled bias loop independent of main transistor terminals.

Key Features

Feature	Design Value
Monolithic ThermalTrak™ bias diode	Same-die thermal coupling eliminates thermal lag between transistor junction and bias network, enabling instant bias correction during dynamic transients.
Extended Safe Operating Area (SOA)	Rated for 4.0 A at V_CE = 50 V (1 s non-repetitive), supporting high peak power delivery without secondary breakdown in music signal peaks.
Matched h_FE pairing capability	Matched h_FE = 50 @ 5 A/5 V available for complementary NPN/PNP pairs, reducing quiescent current mismatch in push-pull outputs.
Pb-free TO-264 package	RoHS-compliant construction with UL 94 V-0 flammability rating and >8 kV HBM ESD protection, suitable for consumer and professional audio manufacturing.

Applications

Home Audio Amplifiers	Professional PA Systems
Use Scenario: High-power stereo amplifier output stage delivering 100+ W RMS per channel into 4–8 Ω speakers with low THD across 20 Hz–20 kHz. IC Role / Device Role / Timing Role: NPN output transistor in complementary Class AB push-pull pair, working with NJL21193DG (PNP) and matched bias diodes. Use Value: Eliminates need for manual bias adjustment during warm-up; maintains <0.05% THD at full power due to real-time thermal tracking.	Use Scenario: Multi-channel public address amplifier driving distributed loudspeaker arrays in stadiums or auditoriums with high crest-factor program material. IC Role / Device Role / Timing Role: Primary output switching element in linear power stage, handling sustained 15 A peaks and 200 W dissipation with thermal integrity. Use Value: Extended SOA prevents thermal runaway during bass-heavy transients; 150°C max junction temperature ensures reliability over 10-year deployments.
Theater Sound Systems	High-End Home Receivers
Use Scenario: Cinema surround sound amplifier requiring ultra-low noise floor and distortion-free reproduction of dynamic film soundtracks. IC Role / Device Role / Timing Role: Final gain stage transistor with integrated bias diode used in discrete feedback topology to minimize thermal drift-induced DC offset. Use Value: Absolute thermal integrity preserves channel balance and imaging stability across 30-minute playback sessions without recalibration.	Use Scenario: Integrated AV receiver output stage supporting multi-zone audio with simultaneous 7.1 channel amplification at moderate power levels. IC Role / Device Role / Timing Role: NPN half of complementary output pair in each channel, mounted on shared heatsink with matched NJL21193DG devices. Use Value: Simplified assembly reduces component count by eliminating external bias diodes and trimmers; lowers labor cost and improves yield.

Home Audio Amplifiers

Professional PA Systems

Use Scenario: High-power stereo amplifier output stage delivering 100+ W RMS per channel into 4–8 Ω speakers with low THD across 20 Hz–20 kHz.

IC Role / Device Role / Timing Role: NPN output transistor in complementary Class AB push-pull pair, working with NJL21193DG (PNP) and matched bias diodes.

Use Value: Eliminates need for manual bias adjustment during warm-up; maintains <0.05% THD at full power due to real-time thermal tracking.

Use Scenario: Multi-channel public address amplifier driving distributed loudspeaker arrays in stadiums or auditoriums with high crest-factor program material.

IC Role / Device Role / Timing Role: Primary output switching element in linear power stage, handling sustained 15 A peaks and 200 W dissipation with thermal integrity.

Use Value: Extended SOA prevents thermal runaway during bass-heavy transients; 150°C max junction temperature ensures reliability over 10-year deployments.

Theater Sound Systems

High-End Home Receivers

Use Scenario: Cinema surround sound amplifier requiring ultra-low noise floor and distortion-free reproduction of dynamic film soundtracks.

IC Role / Device Role / Timing Role: Final gain stage transistor with integrated bias diode used in discrete feedback topology to minimize thermal drift-induced DC offset.

Use Value: Absolute thermal integrity preserves channel balance and imaging stability across 30-minute playback sessions without recalibration.

Use Scenario: Integrated AV receiver output stage supporting multi-zone audio with simultaneous 7.1 channel amplification at moderate power levels.

IC Role / Device Role / Timing Role: NPN half of complementary output pair in each channel, mounted on shared heatsink with matched NJL21193DG devices.

Use Value: Simplified assembly reduces component count by eliminating external bias diodes and trimmers; lowers labor cost and improves yield.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-fidelity audio power transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STMicroelectronics MJL4281A	PNP complement only; no integrated bias diode; V_CEO = 250 V, I_C = 15 A, f_T = 3 MHz	Requires external matched diode and manual bias adjustment; higher thermal lag in dynamic operation	Use when legacy designs mandate ST-compatible footprint and thermal management allows external compensation.
ON Semiconductor MJE15034G	NPN-only; no integrated bias diode; V_CEO = 250 V, I_C = 8 A, P_D = 100 W, R_JC = 1.25°C/W	Half the power rating and thermal performance; unsuitable for >50 W continuous output stages	Select only for lower-power pre-output or driver stage use where ThermalTrak™ functionality is not required.

Compared with NJL21194DG, MJL4281A lacks monolithic thermal matching and requires additional components for bias stability, while MJE15034G offers only half the power handling and thermal efficiency-neither provides the integrated SOA extension or real-time bias tracking that define NJL21194DG's audio-specific value.

Availability

NJL21194DG is available at Aetrix Electronics and suitable for home audio amplifiers, professional PA systems, theater sound systems, and high-end home receivers requiring stable component supply and long-term lifecycle support.

Supply support for NJL21194DG 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensor, and logic solutions for automotive, industrial, and consumer markets.

The ThermalTrak™ transistor product line was engineered specifically for high-fidelity linear audio amplifier output stages, where thermal bias drift directly impacts distortion, channel balance, and long-term reliability.

FAQ

What is the primary function of the integrated diode in NJL21194DG?

The integrated diode in NJL21194DG is a thermally matched bias diode fabricated on the same silicon die as the NPN transistor. It tracks the transistor junction temperature in real time, enabling automatic bias current stabilization in Class AB audio amplifiers without external compensation or manual trimming-this eliminates thermal equilibrium lag and improves dynamic fidelity.

Can NJL21194DG be used without its complementary PNP part NJL21193DG?

Yes, NJL21194DG can operate as a standalone NPN power transistor, but its ThermalTrak™ advantage is fully realized only when paired with NJL21193DG in a complementary push-pull configuration. The matched diode terminals (Pins 4 and 5) are intended to interface with the PNP's base-emitter path to close the thermal feedback loop-using NJL21194DG alone forfeits this core benefit.

What is the maximum safe continuous power dissipation for NJL21194DG at 85°C case temperature?

At T_C = 85°C, NJL21194DG's power dissipation must be derated from its 200 W rating at 25°C using the specified 1.43 W/°C derating factor. This yields 200 W − (1.43 W/°C × 60°C) = 114.2 W maximum continuous dissipation. Exceeding this risks junction temperature exceeding 150°C, triggering thermal shutdown or permanent damage.

Does NJL21194DG require special PCB layout considerations for thermal performance?

Yes-NJL21194DG's TO-264 package features an exposed thermal pad (Pin 3 is collector, but thermal pad is electrically isolated and tied to case). To achieve R_JC = 0.625°C/W, the PCB must include a large copper pour connected to the thermal pad via ≥6 thermal vias (0.3 mm diameter, filled or plated), and the heatsink interface must use high-conductivity thermal compound with uniform pressure across the entire pad surface.

How does NJL21194DG's SOA compare to standard power transistors like the 2SC5200?

NJL21194DG's SOA is explicitly characterized up to 1 s pulse width with I_S/b = 4.0 A at V_CE = 50 V, whereas 2SC5200 data sheets typically specify only DC and short-pulse SOA without secondary breakdown limits at mid-voltage ranges. This makes NJL21194DG more predictable for high-crest-factor audio signals, reducing risk of destructive second breakdown during bass transients.

NJL21194DG Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-264-5

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 16 A

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

Vce Saturation (Max) @ Ib, Ic:: 4V @ 3.2A, 16A

Current - Collector Cutoff (Max):: 100µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 25 @ 8A, 5V

Power - Max:: 200 W

Frequency - Transition:: 4MHz

Operating Temperature:: -65°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-264

NJL21194DG FAQ

1.How can I place an order for NJL21194DG through Aetrix?

Please submit a Request for Quotation (RFQ) for NJL21194DG 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 NJL21194DG reliable?

The price and inventory of NJL21194DG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NJL21194DG is usually 5 days.

3.What payment methods are accepted for NJL21194DG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NJL21194DG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for NJL21194DG?

NJL21194DG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your NJL21194DG 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 NJL21194DG?

For technical support, including NJL21194DG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NJL21194DG requirements.

6.How does Aetrix verify that NJL21194DG is sourced from the original manufacturer or authorized distributors?

All NJL21194DG 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 NJL21194DG meets industry standards.

7.What is the process for return or replacement of NJL21194DG?

All NJL21194DG units undergo pre-shipment inspection (PSI). If there is an issue with NJL21194DG, 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 NJL21194DG part is unused and in its original packaging.

Return procedure for NJL21194DG:

1.Submit a request within 90 days.

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

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