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Home > Products > Discrete Semiconductor Products > Diodes > Rectifiers > Single Diodes

STMicroelectronics SMBYT03-400

Name: SMBYT03-400
Brand: STMicroelectronics
SKU: SMBYT03-400
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SMBYT03-400

Manufacturer:: STMicroelectronics

Category:: Single Diodes

Package:: DO-214AB, SMC

Datasheet:: SMBYT03-400.pdf

Description:: DIODE GEN PURP 400V 3A SMC

Quantity:: RFQ Add To RFQ list

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Inventory:7,452

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Product details

Overview

SMBYT03-400 from STMicroelectronics is a surface-mount fast recovery rectifier diode rated for 400 V repetitive peak reverse voltage, 3 A average forward current at T_L = 55°C (duty cycle 0.5), and 60 A non-repetitive surge current (10 ms sinusoidal), used as a high-voltage output rectifier in offline SMPS and DC-DC converters.

For engineers reviewing the SMBYT03-400 datasheet, SMBYT03-400 pinout, SMBYT03-400 application, or SMBYT03-400 equivalent, key selection criteria include reverse recovery time (25 ns typ. at 25°C), low conduction loss (V_F = 1.05–1.4 V at 100°C/3 A), thermal resistance (R_th(j-l) = 20 °C/W), and SMC package compatibility with high-power density layouts.

Technical Context

This diode employs a planar passivated silicon junction optimized for fast turn-off with low stored charge (Q_rr not specified but implied by t_rr ≤ 60 ns and I_RM ≤ 2 A under dI_F/dt = –50 A/µs). Its low noise switching and minimal reverse recovery overshoot support EMI-sensitive power supplies.

The device operates across –40 to +150°C junction temperature, with thermal design anchored to R_th(j-l) = 20 °C/W and R_th(j-a) = 65 °C/W (1 cm² copper per lead), enabling stable performance in thermally constrained SMC footprint applications up to 2.5 W average dissipation.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	400 V - Withstands 400 V repetitive reverse bias without breakdown; suitable for 230 VAC input rectification with safety margin.
I_F(AV)	3 A at T_L = 55°C, δ = 0.5 - Supports continuous 3 A DC output in well-heatsinked SMPS secondary-side rectification.
t_rr	25 ns (typ.) at 25°C - Enables high-frequency switching (>100 kHz) with minimal reverse recovery loss and voltage spikes.
V_F	1.05–1.4 V at 3 A / 100°C - Low forward drop reduces conduction loss; P_cond ≈ 1.1×I_F(AV) + 0.08×I_F(RMS)².
R_th(j-l)	20 °C/W - Junction-to-leads thermal resistance enables direct PCB copper thermal path design without external heatsink.
I_FSM	60 A (10 ms sinusoidal) - Handles inrush and transient overloads typical in AC-DC front-end and PFC stages.

Pinout & Package

Package: SMC (DO-214AB), surface-mount, single-diode configuration with cathode marked by laser "C4" symbol and molded cathode band.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry node	Connected to transformer secondary or switch node; must handle 60 A surge and high dI/dt.
Cathode	Forward current exit / reverse blocking terminal	Marked side; ties to output capacitor ground return; critical for minimizing loop inductance in high-speed rectification.

Key Features

Feature	Design Value
Fast recovery time	t_rr ≤ 60 ns ensures low switching loss and reduced EMI in >100 kHz SMPS designs.
Low thermal resistance	R_th(j-l) = 20 °C/W allows direct PCB copper conduction cooling-no extra thermal vias required for ≤2.5 W operation.
High surge rating	60 A I_FSM supports robustness against line transients and startup surges in industrial power supplies.
Low-noise turn-off	Controlled reverse recovery minimizes voltage overshoot and ringing, easing EMI filter design.

Applications

Server PSU Output Rectification

Industrial DC-DC Converter

Use Scenario: Secondary-side 12 V/24 V rectification in 80 PLUS Titanium server PSUs operating at 200–500 kHz.

IC Role / Device Role / Timing Role: Fast recovery diode replacing Schottky in higher-voltage rails where V_RRM > 200 V is required.

Use Value: 25 ns t_rr cuts switching loss by ~35% vs. standard recovery diodes, improving full-load efficiency by 0.4–0.6%.

Use Scenario: Isolated 48 V output stage in programmable logic controller (PLC) power modules.

IC Role / Device Role / Timing Role: High-reliability output rectifier handling 3 A continuous load with 60 A surge tolerance during motor startup.

Use Value: R_th(j-l) = 20 °C/W enables stable operation at T_j ≤ 125°C on 2 oz copper without forced air.

LED Driver Secondary Rectification

Telecom DC-DC Brick

Use Scenario: Constant-current LED driver output stage delivering 350 mA–1 A at 36–48 V with high ripple rejection.

IC Role / Device Role / Timing Role: Low-noise rectifier minimizing conducted EMI into sensitive analog feedback paths.

Use Value: Controlled reverse recovery suppresses high-frequency ringing, reducing need for snubbers and saving board space.

Use Scenario: 48 V input, 3.3 V/5 V isolated DC-DC brick for base station RF modules.

IC Role / Device Role / Timing Role: Input-stage rectifier in active clamp forward or LLC resonant converter front-end.

Use Value: 400 V V_RRM accommodates reflected transients up to 350 V, meeting IEC 61000-4-5 Level 4 surge immunity.

Availability

SMBYT03-400 is available at Aetrix Electronics and suitable for server power supplies, industrial DC-DC converters, LED drivers, and telecom DC-DC bricks requiring stable component supply and long-term manufacturability.

Supply support for SMBYT03-400 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 SMBYT series belongs to ST's high-voltage fast recovery rectifier product line, engineered specifically for high-efficiency, high-frequency switched-mode power conversion in compact surface-mount form factors.

FAQ

Is SMBYT03-400 still in active production?

No-SMBYT03-400 is marked "Obsolete Product(s)" in the official ST datasheet (Ed: 2C, October 1999). It remains available through authorized legacy distributors and Aetrix Electronics' extended-life inventory program with full traceability and RoHS-compliant lot documentation.

What is the cathode marking convention for SMBYT03-400?

The cathode is identified by a laser-marked "C4" symbol on the top surface and a molded cathode band on the body. Per ST's SMC mechanical drawing, the banded end corresponds to the cathode terminal, consistent with industry-standard polarity orientation for DO-214AB packages.

Can SMBYT03-400 replace SMBY3-400 in existing designs?

Yes-SMBYT03-400 and SMBY3-400 share identical electrical specs (V_RRM, I_F(AV), t_rr, R_th(j-l)) and SMC package dimensions. The "T" suffix denotes tape-and-reel packaging; both are functionally and mechanically interchangeable in PCB layout and thermal design.

What is the recommended minimum copper area per lead for thermal performance?

ST specifies R_th(j-a) = 65 °C/W with 1 cm² of 35 µm-thick copper per lead (epoxy PCB). For optimal thermal performance, use ≥1.2 cm² per lead with ≥2 thermal vias (0.3 mm diameter, filled) directly under each pad to maintain T_j ≤ 125°C at 3 A continuous load.

SMBYT03-400 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: DO-214AB, SMC

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Technology:: Standard

Voltage - DC Reverse (Vr) (Max):: 400 V

Current - Average Rectified (Io):: 3A

Voltage - Forward (Vf) (Max) @ If:: 1.5 V @ 3 A

Speed:: Fast Recovery =< 500ns, > 200mA (Io)

Reverse Recovery Time (trr):: 60 ns

Current - Reverse Leakage @ Vr:: 10 µA @ 400 V

Capacitance @ Vr, F:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SMC

Operating Temperature - Junction:: -40°C ~ 150°C

SMBYT03-400 FAQ

1.How can I place an order for SMBYT03-400 through Aetrix?

Please submit a Request for Quotation (RFQ) for SMBYT03-400 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 SMBYT03-400 reliable?

The price and inventory of SMBYT03-400 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBYT03-400 is usually 5 days.

3.What payment methods are accepted for SMBYT03-400?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBYT03-400 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SMBYT03-400?

SMBYT03-400 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SMBYT03-400 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 SMBYT03-400?

For technical support, including SMBYT03-400 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBYT03-400 requirements.

6.How does Aetrix verify that SMBYT03-400 is sourced from the original manufacturer or authorized distributors?

All SMBYT03-400 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 SMBYT03-400 meets industry standards.

7.What is the process for return or replacement of SMBYT03-400?

All SMBYT03-400 units undergo pre-shipment inspection (PSI). If there is an issue with SMBYT03-400, 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 SMBYT03-400 part is unused and in its original packaging.

Return procedure for SMBYT03-400:

1.Submit a request within 90 days.

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

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