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

STMicroelectronics BUR51

Name: BUR51
Brand: STMicroelectronics
SKU: BUR51
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BUR51

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-204AA, TO-3

Datasheet:: BUR51.pdf

Description:: TRANS NPN 200V 60A TO-3

Quantity:: RFQ Add To RFQ list

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Inventory:3,882

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Product details

Overview

BUR51 from STMicroelectronics is a high-current NPN silicon power transistor in a modified JEDEC TO-3 metal package, designed for switching and linear amplification in industrial and military-grade power conversion systems. It supports 200 V V_CEO, 60 A continuous collector current, 350 W total dissipation at T_c ≤ 25 °C, and operates up to 200 °C junction temperature - deployed in high-reliability DC-DC converters and motor drive output stages.

For engineers reviewing the BUR51 datasheet, BUR51 pinout, BUR51 application, or BUR51 equivalent, key selection criteria include its 0.5 °C/W junction-to-case thermal resistance, 20–100 h_FE gain range (IC = 5–50 A), clamped second-breakdown capability (50 A at V_clamp = 200 V), and fast switching performance (t_on = 0.35 µs, t_s = 0.9 µs) under pulsed 50 A/100 V conditions.

Technical Context

The BUR51 employs a multiepitaxial planar structure optimized for rugged high-current switching, with built-in second-breakdown robustness (I_s/b = 17.5 A at V_CE = 20 V, t = 1 s) and clamped energy handling (50 A with 500 µH inductive load). Its f_T of 10–16 MHz enables stable operation in medium-frequency PWM circuits up to ~100 kHz.

Designed for hard-switching topologies, it features low saturation voltages (V_CE(sat) = 0.9–1.5 V at IC = 30–50 A), tight V_BE(sat) control (1.55–2.0 V), and guaranteed V_CEO(sus) = 200 V under sustained blocking - critical for snubberless flyback and forward converter primary switches.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	200 V - maximum safe collector-emitter voltage with base open; defines usable bus voltage headroom in 160 V DC systems.
I_C	60 A continuous - steady-state current rating at T_c = 25 °C; requires heatsink design for >40 A operation.
P_tot	350 W at T_c ≤ 25 °C - total power dissipation limit; derates linearly above 25 °C case temperature.
R_thj-case	0.5 °C/W - junction-to-case thermal resistance; enables direct mounting to cold plates without interface pads for high-power density.
h_FE	20–100 - DC current gain at V_CE = 4 V; supports base drive optimization across 5–50 A load range.
t_on/t_s	0.35 µs / 0.9 µs - turn-on and storage time at I_C = 50 A, V_CC = 100 V; determines minimum practical switching period in hard-switched SMPS.

Pinout & Package

Package: Modified JEDEC TO-3 metal case (case outline P003I), with electrically isolated collector tab, intended for direct heatsink mounting and high-reliability thermal management.

Pin/Terminal	Circuit Role	Design Meaning
Collector (Case Tab)	Main current path input/output terminal	Electrically connected to metal case; must be insulated from heatsink unless system ground reference permits direct mounting.
Base (Lead 1)	Control electrode for transistor conduction	Requires 2–5 A peak drive current to achieve full saturation at 30–50 A collector load; low V_BE(sat) minimizes driver losses.
Emitter (Lead 2)	Current return path and reference node	Serves as common emitter node in grounded-emitter configurations; low-inductance layout critical for fast switching stability.

Key Features

Feature	Design Value
Multiepitaxial planar structure	Enables uniform current distribution and high secondary breakdown immunity (I_s/b = 17.5 A at V_CE = 20 V, t = 1 s).
Clamped second-breakdown rating	50 A at V_clamp = 200 V with 500 µH inductive load - allows safe operation without external snubbers in flyback converters.
High junction temperature rating	200 °C max operating temperature - supports sealed or high-ambient environments (e.g., avionics enclosures, industrial motor drives).
Low saturation voltage	V_CE(sat) = 0.9 V (IC = 30 A, IB = 2 A) - reduces conduction loss by ~30% vs. legacy 1.3 V devices at same current.

Applications

Industrial Motor Drive Output Stage

Military DC-DC Converter Primary Switch

Use Scenario: High-current H-bridge leg in 48–110 V DC servo drives requiring >40 A peak output and thermal resilience.

IC Role / Device Role / Timing Role: NPN power switch in complementary emitter-follower configuration; handles bidirectional current with fast turn-off (t_f = 0.24 µs).

Use Value: 0.5 °C/W R_thj-case enables compact heatsink integration; 200 °C T_j rating avoids derating in convection-cooled chassis.

Use Scenario: Primary-side switching transistor in 28 V input, 200 V output military-grade forward converter with strict EMI and reliability requirements.

IC Role / Device Role / Timing Role: Hard-switched main switch operating at 50–100 kHz; leverages clamped I_s/b = 50 A to eliminate snubber networks.

Use Value: V_CEO(sus) = 200 V ensures margin against reflected transients; 10–16 MHz f_T supports clean gate drive waveform integrity.

High-Voltage Linear Regulator Pass Element

Welding Power Supply Output Stage

Use Scenario: Series pass device in 150 V input, 12–24 V adjustable linear regulator for test equipment requiring ultra-low noise and zero switching artifacts.

IC Role / Device Role / Timing Role: Linear-mode current amplifier with fixed base bias; dissipates up to 250 W continuously under worst-case dropout.

Use Value: 350 W P_tot at T_c = 25 °C and 0.5 °C/W thermal resistance allow stable 200 W operation with modest forced-air cooling.

Use Scenario: Output chopper in 3-phase IGBT-gated welding inverter delivering 300 A DC arc current with rapid duty cycling.

IC Role / Device Role / Timing Role: High-current freewheeling switch in resonant snubber network; conducts 60 A average with 80 A I_CM peaks.

Use Value: I_CM = 80 A (10 ms) and 200 °C T_j withstand repeated thermal shock during arc ignition and short-circuit recovery.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-current NPN switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BU508A	V_CEO = 150 V, I_C = 25 A, P_tot = 125 W - lower voltage/current ratings and thermal capability.	Suitable only for ≤120 V bus systems and <30 A loads; lacks clamped second-breakdown specification.	Select when cost sensitivity outweighs 200 V/60 A requirement and thermal margin is less constrained.
2N6277	V_CEO = 200 V, I_C = 40 A, P_tot = 200 W, R_thj-case = 0.75 °C/W - reduced current and thermal performance.	Acceptable for 20–35 A industrial SMPS but requires larger heatsink; no published clamped I_s/b data.	Choose where legacy qualification or dual-sourcing mandates ON Semiconductor parts, accepting 30% lower power density.

Compared with BU508A and 2N6277, the BUR51 delivers 2.4× higher continuous current, 1.75× greater power dissipation, and verified clamped second-breakdown robustness - making it uniquely suited for mission-critical 200 V, 60 A switching nodes where thermal and transient resilience are non-negotiable.

Availability

BUR51 is available at Aetrix Electronics and suitable for industrial motor drives, military DC-DC converters, and high-voltage linear regulators requiring stable component supply and long-term obsolescence mitigation support.

Supply support for BUR51 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power discrete devices, microcontrollers, and automotive ICs with vertical manufacturing and rigorous military-grade qualification processes.

The BUR51 belongs to ST's high-reliability power transistor product line, engineered specifically for demanding linear and switching applications in defense, aerospace, and heavy industrial systems where thermal endurance and transient robustness are paramount.

FAQ

Is the BUR51 still in active production?

No - the BUR51 is marked "Obsolete Product(s)" in ST's official documentation (2003 datasheet revision). However, Aetrix Electronics maintains legacy inventory with full traceability and offers extended lifecycle support including cross-reference engineering and controlled-batch release for ongoing production programs.

Can the BUR51 be used in avalanche mode?

No - the BUR51 is not rated or characterized for repetitive avalanche operation. Its V_CEO(sus) = 200 V and clamped I_s/b = 50 A apply only to single-pulse inductive switching events; sustained avalanche stress exceeds safe operating area limits and risks immediate failure.

What is the recommended heatsink interface for the TO-3 case?

A thermally conductive insulating pad (e.g., mica + silicone grease or polymer-based film) is required unless the collector (case) is intentionally tied to system ground. Direct metal-to-metal mounting is permitted only when electrical isolation is unnecessary and thermal interface resistance is minimized to maintain R_thj-amb < 1.2 °C/W.

Does the BUR51 have a documented SOA curve?

Yes - the datasheet provides a Safe Operating Area (SOA) graph covering DC, pulsed (10 ms, 100 µs), and second-breakdown boundaries up to 200 °C. The curve confirms 60 A/200 V DC operation is limited by thermal constraints, while 50 A/200 V is viable for ≤10 ms pulses with adequate heatsinking.

BUR51 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-204AA, TO-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 60 A

Voltage - Collector Emitter Breakdown (Max):: 200 V

Vce Saturation (Max) @ Ib, Ic:: 1.5V @ 5A, 50A

Current - Collector Cutoff (Max):: 1mA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 20 @ 5A, 4V

Power - Max:: 350 W

Frequency - Transition:: 16MHz

Operating Temperature:: 200°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Chassis Mount

Supplier Device Package:: TO-3

BUR51 FAQ

1.How can I place an order for BUR51 through Aetrix?

Please submit a Request for Quotation (RFQ) for BUR51 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 BUR51 reliable?

The price and inventory of BUR51 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUR51 is usually 5 days.

3.What payment methods are accepted for BUR51?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUR51 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BUR51?

BUR51 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BUR51 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 BUR51?

For technical support, including BUR51 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUR51 requirements.

6.How does Aetrix verify that BUR51 is sourced from the original manufacturer or authorized distributors?

All BUR51 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 BUR51 meets industry standards.

7.What is the process for return or replacement of BUR51?

All BUR51 units undergo pre-shipment inspection (PSI). If there is an issue with BUR51, 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 BUR51 part is unused and in its original packaging.

Return procedure for BUR51:

1.Submit a request within 90 days.

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

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