Counterfeit and defect prevention
Visual and packaging inspection
Electrical performance verification
Service Email:
[email protected]
>
BUL804
STMicroelectronics
TRANS NPN 450V 4A TO220
1540 Pcs New Original In Stock
Bipolar (BJT) Transistor NPN 450 V 4 A 70 W Through Hole TO-220
Request Quote
(Ships tomorrow)
*Quantity
Minimum 1
Minimum 1
5.0 / 5.0
- (459 Ratings)
BUL804
Product Overview
12880401
DiGi Electronics Part Number
BUL804-DGManufacturer
STMicroelectronics
BUL804
Description
TRANS NPN 450V 4A TO220Inventory
1540 Pcs New Original In Stock
Bipolar (BJT) Transistor NPN 450 V 4 A 70 W Through Hole TO-220
Quantity
Minimum 1
Minimum 1
Purchase and inquiry
Warranty & Returns
How to Order
Shipping & Delivery
Quality Assurance
365 - Day Quality Guarantee - Every part fully backed.
90 - Day Refund or Exchange - Defective parts? No hassle.
Limited Stock, Order Now - Get reliable parts without worry.
Global Shipping & Secure Packaging
Worldwide Delivery in 3-5 Business Days
100% ESD Anti-Static Packaging
Real-Time Tracking for Every Order
Secure & Flexible Payment
Credit Card, VISA, MasterCard, PayPal, Western Union, Telegraphic Transfer(T/T) and more
All payments encrypted for security
BUL804 Technical Specifications
Category
Transistors, Bipolar (BJT), Single Bipolar Transistors
Packaging
-
Series
-
Product Status
Obsolete
Transistor Type
NPN
Current - Collector (Ic) (Max)
4 A
Voltage - Collector Emitter Breakdown (Max)
450 V
Vce Saturation (Max) @ Ib, Ic
1.2V @ 500mA, 2.5A
Current - Collector Cutoff (Max)
250µA
DC Current Gain (hFE) (Min) @ Ic, Vce
10 @ 2A, 5V
Power - Max
70 W
Frequency - Transition
-
Operating Temperature
150°C (TJ)
Mounting Type
Through Hole
Package / Case
TO-220-3
Supplier Device Package
TO-220
Base Product Number
BUL804
Datasheet & Documents
Datasheets
Download BUL804 Product Specification (PDF)
HTML Datasheet
BUL804-DG
Environmental & Export Classification
RoHS Status
ROHS3 Compliant
Moisture Sensitivity Level (MSL)
1 (Unlimited)
REACH Status
REACH Unaffected
ECCN
EAR99
HTSUS
8541.29.0095
Additional Information
Standard Package
50
Alternative Parts
View DetailsPART NUMBER
MANUFACTURER
QUANTITY AVAILABLE
DiGi PART NUMBER
UNIT PRICE
SUBSTITUTE TYPE
Reviews
5.0/5.0-(Show up to 5 Ratings)
December 02, 2025
Ils offrent un service client courtois et efficace, je recommande vivement.
December 02, 2025
The support team is knowledgeable and always ready to assist with any questions I have.
December 02, 2025
The support staff is friendly and knowledgeable, resolving my concerns with patience.
December 02, 2025
They follow up after purchases to ensure my satisfaction and resolve any issues quickly.
December 02, 2025
Their after-sales team works tirelessly to ensure my problems are solved swiftly.
December 02, 2025
The packaging design prioritized safety, making me feel confident about the integrity of my order.
December 02, 2025
DiGi Electronics offers incredibly fast shipping, ensuring I receive my orders promptly every time.
Publish Evalution
Evalution Message
Please enter your review message.
Please post honest comments and do not post ilegal comments.
Frequently Asked Questions (FAQ)
What are the key design risks when replacing the BUL804 with the FJP3305H2TU in a high-voltage switching application?
When substituting the BUL804 with the FJP3305H2TU, verify that the lower maximum collector current (3A vs. 4A) and reduced power dissipation (50W vs. 70W) of the FJP3305H2TU won't exceed thermal limits under peak load. Also, ensure the FJP3305H2TU’s higher Vce(sat) at 2.5A affects switching efficiency and heat generation. Always revalidate thermal performance and derating in your specific layout when replacing the BUL804.
How can I ensure long-term reliability of the BUL804 in a TO-220-based power supply operating near 150°C junction temperature?
To maintain reliability of the BUL804 near its 150°C max junction temperature, use a properly sized heatsink with low thermal resistance and consider forced airflow if ambient exceeds 60°C. Monitor actual dissipation under transient loads and apply at least 20°C derating margin. Additionally, due to the BUL804 being obsolete, secure a long-term supply or design in a replacement like the BUL1102E with similar ruggedness and voltage headroom.
What practical issues arise when using the BUL804 in place of the BUT11A in flyback converter designs?
While the BUL804 and BUT11A both support 450V operation, the BUL804 offers higher continuous collector current (4A vs. 3A) and better power handling (70W vs. 50W), making it suitable for upgraded or derated flyback designs. However, verify base drive compatibility—BUL804 requires sufficient base current (≥500mA) for hard saturation at 2.5A due to its modest hFE (min 10). Inadequate drive can increase switching losses and thermal stress compared to the BUT11A.
What thermal design considerations should be addressed when operating the BUL804 at full 4A collector current?
Operating the BUL804 at 4A requires careful thermal management due to its 70W power dissipation limit. Even with a TO-220 package, junction-to-case resistance (~1.43°C/W) combined with heatsink and interface resistance can quickly approach thermal shutdown. Use copper pour, multiple vias, and a heatsink with active cooling if duty cycle exceeds 50%. Also apply SOA (Safe Operating Area) curves to ensure the BUL804 isn’t exposed to simultaneous high voltage and current that could cause second breakdown.
Why might the BUL804 exhibit unexpected turn-on in high-noise industrial environments, and how can this be mitigated?
The BUL804, like all BJTs, is susceptible to false triggering from voltage transients at the base-collector junction due to its gain-bandwidth product and junction capacitance. In high-noise settings, induced base currents can inadvertently turn on the device. To mitigate this, add a base-to-emitter resistor (1–10kΩ) to shunt leakage currents, use snubber networks across CE terminals, and ensure tight gate drive shielding. Also consider replacing the BUL804 with a ruggedized IGBT if noise immunity is a persistent issue.
Quality Assurance (QC)
DiGi ensures the quality and authenticity of every electronic component through professional inspections and batch sampling, guaranteeing reliable sourcing, stable performance, and compliance with technical specifications, helping customers reduce supply chain risks and confidently use components in production.
BUL804 CAD Models
STMicroelectronics BUL804 PCB symbols & footprints
productDetail
