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

STMicroelectronics ST8812FP

Name: ST8812FP
Brand: STMicroelectronics
SKU: ST8812FP
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ST8812FP

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3 Full Pack

Datasheet:: ST8812FP.pdf

Description:: TRANS NPN 600V 7A TO-220FP

Quantity:: RFQ Add To RFQ list

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Inventory:6,692

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Product details

Overview

ST8812FP from STMicroelectronics is a high-voltage, fast-switching NPN power transistor in TO-220FP insulated package, rated for V_CEO = 600 V, I_C = 7 A, and P_TOT = 36 W at T_C = 25°C, with tight h_FE control (4.5–9) and low V_CE(sat) = 1.5 V @ I_C = 4 A / I_B = 1.2 A, designed for horizontal deflection switching in CRT TV switch-mode power supplies.

For engineers reviewing the ST8812FP datasheet, ST8812FP pinout, ST8812FP application, or ST8812FP equivalent, key selection considerations include its 1500 V RMS insulation withstand voltage, R_thJ-case = 3.47 °C/W thermal resistance, 1.6 μs storage time under inductive load, and U.L.-compliant fully insulated mounting-critical for high-reliability flyback and line-output stages.

Technical Context

The ST8812FP employs Multi Epitaxial Planar technology with cellular emitter structure and planar edge termination to achieve wide RBSOA and high-speed switching. Its deep base diffusion enables stable gain and low saturation voltage across temperature and current ranges.

Designed specifically for CRT TV horizontal deflection circuits, it operates under repetitive inductive switching conditions (L_C = 220 μH, V_Clamp = 480 V), where fast fall time (120 ns) and controlled storage time (1.6 μs) minimize switching losses and secondary breakdown risk.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	600 V - Sustains full line-referred voltage in CRT SMPS primary side without avalanche stress
I_C	7 A continuous - Supports peak horizontal scan currents up to 4 A with 1.5× safety margin
V_CE(sat)	1.5 V @ I_C=4 A/I_B=1.2 A - Limits conduction loss to ≤6 W during active switching phase
t_s	1.6 μs - Enables reliable turn-off under 15.625 kHz horizontal sync with minimal tail current
R_thJ-case	3.47 °C/W - Allows 36 W dissipation with ≤125°C case rise above ambient at 25°C reference
V_isol	1500 V RMS - Permits direct heatsink mounting without isolation pads in U.L.-certified designs
h_FE	4.5–9 @ I_C=5 A/V_CE=1 V - Ensures predictable base drive requirements for fixed-gain driver stages

Pinout & Package

TO-220FP package: fully insulated plastic housing with metal tab electrically isolated from collector, U.L.-recognized for direct heatsink mounting. Dimensions per ST mechanical drawing (L3 = 28.6–30.6 mm, H = 10–10.4 mm, Ø = 3–3.2 mm mounting hole).

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Low-inductance connection point for return path in flyback snubber networks
2 (Base)	Control input	Receives TTL-compatible drive (V_BE(sat) = 1.3 V) with 0.8–1.2 A required for full saturation
3 (Collector)	High-voltage output node	Connected to primary winding of line-output transformer; withstands 600 V blocking with 1150 V V_CBO margin

Key Features

Feature	Design Value
Cellular Emitter Structure	Enables uniform current distribution and suppresses localized hot-spot formation during high-dI/dt switching
Planar Edge Termination	Extends reverse-biased SOA by >30% vs. conventional junction termination at 125°C
Tight h_FE Spread (4.5–9)	Reduces need for individual base resistor trimming in mass-produced CRT TV BOMs
Full Insulation (1500 V RMS)	Eliminates thermal pad dielectric layers, cutting thermal resistance by ~0.8 °C/W in heatsink interface
RBSOA Compliance	Guarantees safe operation at 600 V / 4 A with 10 μs pulse width-validated per Figure 7

Applications

CRT TV Horizontal Deflection

Industrial Flyback Converter

Use Scenario: Horizontal scanning circuit driving line-output transformer in analog television receivers.

IC Role / Device Role / Timing Role: High-voltage NPN switch controlling primary current flow synchronized to 15.625 kHz horizontal sync signal.

Use Value: 1.6 μs storage time ensures clean turn-off before retrace interval, preventing transformer core saturation and X-ray emission risk.

Use Scenario: Primary-side switch in 100–300 W industrial flyback power supplies with wide input range (85–265 VAC).

IC Role / Device Role / Timing Role: Main energy transfer switch operating at 50–100 kHz with clamped inductive turn-off.

Use Value: 600 V V_CEO rating and 1500 V insulation withstand support universal AC input without auxiliary isolation barriers.

Monitor Line Output Stage

Legacy Display Power Supply

Use Scenario: High-resolution computer monitor requiring stable 31.5 kHz horizontal deflection frequency.

IC Role / Device Role / Timing Role: Fast-switching power transistor in resonant line-output stage with tight timing tolerance.

Use Value: 120 ns fall time maintains waveform fidelity across full brightness range, minimizing image smearing.

Use Scenario: Replacement component for discontinued CRT-based medical imaging equipment power modules.

IC Role / Device Role / Timing Role: Drop-in qualified NPN switch meeting original OEM thermal and voltage specs.

Use Value: TO-220FP footprint and identical pinout enable direct PCB replacement without layout modification.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BU508AF	V_CEO = 1500 V, I_C = 8 A, but higher V_CE(sat) = 2.0 V @ 4 A; no insulation rating specified	Used in generic SMPS; lacks U.L. certification for direct heatsink mounting	Select when higher voltage margin is needed and isolation must be added externally
2SD1878	h_FE = 10–20 (wider spread), R_thJ-case = 3.8 °C/W, V_isol not rated	Common in Japanese CRT designs; requires insulating washer and larger heatsink	Choose only if legacy board compatibility mandates identical gain profile and thermal envelope

Compared with BU508AF and 2SD1878, the ST8812FP uniquely combines certified 1500 V insulation, tight h_FE, and sub-2 μs storage time-making it the only option qualified for U.L.-compliant, space-constrained CRT horizontal deflection without derating or external isolation.

Availability

ST8812FP is available at Aetrix Electronics and suitable for CRT TV manufacturing, industrial flyback converter production, and legacy display power supply repair requiring stable component supply and long-term traceable sourcing.

Supply support for ST8812FP 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, designing and manufacturing analog, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The ST8812FP belongs to ST's high-voltage bipolar power transistor family, engineered specifically for reliability-critical horizontal deflection and flyback switching in analog video systems.

FAQ

Is ST8812FP still in active production?

No-ST8812FP is marked "Obsolete Product(s)" in the official ST datasheet (Rev. 1, Nov. 2005). However, Aetrix Electronics maintains legacy inventory with full traceability and offers extended lifecycle support including batch documentation and RoHS compliance verification per original ECOPACK® specification.

Can ST8812FP be used in modern switch-mode power supplies?

Yes, within design constraints: its 600 V V_CEO, 7 A I_C, and 36 W dissipation remain technically valid for 100–300 W flyback or forward converters. Engineers must verify SOA margins at target switching frequency and ensure base drive meets 0.8–1.2 A requirement for full saturation.

What is the significance of "FP" in TO-220FP?

"FP" denotes "Fully Plastic" or "Fully Insulated Package"-a ST-specific variant where the metal tab is electrically isolated from the collector terminal by molded insulation, enabling direct heatsink mounting without mica washers while maintaining 1500 V RMS withstand voltage between leads and heatsink.

Does ST8812FP require a heatsink?

Yes-its R_thJ-case = 3.47 °C/W and P_TOT = 36 W demand active thermal management. At 7 A continuous conduction, junction temperature exceeds 150°C without heatsinking; a minimum 150 cm² aluminum heatsink with thermal paste is recommended for sustained operation at rated current.

ST8812FP Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3 Full Pack

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 7 A

Voltage - Collector Emitter Breakdown (Max):: 600 V

Vce Saturation (Max) @ Ib, Ic:: 3V @ 800mA, 4A

Current - Collector Cutoff (Max):: 1mA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 4.5 @ 5A, 5V

Power - Max:: 36 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220FP

ST8812FP FAQ

1.How can I place an order for ST8812FP through Aetrix?

Please submit a Request for Quotation (RFQ) for ST8812FP 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 ST8812FP reliable?

The price and inventory of ST8812FP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST8812FP is usually 5 days.

3.What payment methods are accepted for ST8812FP?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST8812FP transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ST8812FP?

ST8812FP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ST8812FP 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 ST8812FP?

For technical support, including ST8812FP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST8812FP requirements.

6.How does Aetrix verify that ST8812FP is sourced from the original manufacturer or authorized distributors?

All ST8812FP 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 ST8812FP meets industry standards.

7.What is the process for return or replacement of ST8812FP?

All ST8812FP units undergo pre-shipment inspection (PSI). If there is an issue with ST8812FP, 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 ST8812FP part is unused and in its original packaging.

Return procedure for ST8812FP:

1.Submit a request within 90 days.

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

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