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

STMicroelectronics BYT03-400

Name: BYT03-400
Brand: STMicroelectronics
SKU: BYT03-400
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BYT03-400

Manufacturer:: STMicroelectronics

Category:: Single Diodes

Package:: DO-201AD, Axial

Datasheet:: BYT03-400.pdf

Description:: DIODE GEN PURP 400V 3A DO201AD

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Product details

Overview

BYT03-400 from STMicroelectronics is an ultrafast switching diode optimized for base drive and transistor snubbing circuits, featuring 400 V repetitive peak reverse voltage, 3 A average forward current at 55°C, 25 ns maximum reverse recovery time, 1.4 V max forward voltage at 3 A/100°C, and DO-201AD axial package - deployed in SMPS flyback clamp and IGBT freewheeling paths.

For engineers reviewing the BYT03-400 datasheet, BYT03-400 pinout, BYT03-400 application, or BYT03-400 equivalent, key selection criteria include ultrafast trr (≤25 ns), low conduction loss (VF ≤1.4 V @ 3 A/100°C), surge robustness (60 A IFSM), thermal resistance (20 °C/W on infinite heatsink), and axial DO-201AD mechanical compatibility with through-hole power layouts.

Technical Context

This diode employs ST's planar 400 V technology to minimize both conduction and switching losses, enabling high-frequency operation up to several hundred kHz in hard-switched topologies. Its low Qrr and negligible tail current support clean turn-off in inductive switching nodes.

The device operates with junction temperatures up to 150°C and exhibits stable reverse leakage (<0.5 mA @ 100°C, VR = VRRM) and predictable dynamic behavior across dIF/dt (up to −50 A/µs), making it suitable for fast transient control in DC-DC converters and motor drive clamping.

Key Specifications

Parameter	Value and Actual Design Meaning
VRRM	400 V - Withstands repetitive reverse voltage in flyback snubber and freewheeling paths without breakdown.
IF(AV)	3 A @ TI = 55°C, δ = 0.5 - Sustains continuous forward current in medium-power SMPS output rectification.
trr (max)	25 ns - Enables efficient operation at >200 kHz switching frequencies with minimal switching loss.
VF (max)	1.4 V @ IF = 3 A, Tj = 100°C - Limits conduction loss to <4.2 W under full-load conditions.
IFSM	60 A @ tp = 10 ms, sinusoidal - Handles inrush and fault currents in power supply startup and overload scenarios.
Rth(j-a)	20 °C/W - Requires minimum heatsinking (e.g., 10 mm lead length on FR4 PCB) to maintain Tj ≤150°C at full load.

Pinout & Package

DO-201AD axial package: hermetically sealed glass body with tinned copper alloy leads; 9.5 mm body length, 25.4 mm overall length, 1.3 mm lead diameter, 5.3 mm body diameter; weight 1.16 g; UL 94 V0 epoxy encapsulation.

Pin/Terminal	Circuit Role	Design Meaning
Anode (A)	Forward current entry point	Connected to switched node (e.g., IGBT collector or transformer primary) in freewheeling path.
Cathode (K)	Forward current exit / reverse blocking terminal	Connected to return rail or energy storage node; withstands 400 V reverse bias during off-state.

Key Features

Feature	Design Value
Ultrafast reverse recovery	trr ≤25 ns ensures minimal switching loss and EMI in high-frequency SMPS and motor drives.
Low forward voltage drop	VF ≤1.4 V @ 3 A/100°C reduces conduction loss and thermal stress in compact power stages.
High surge current capability	60 A non-repetitive peak supports robust startup and fault tolerance in industrial power supplies.
Wide operating temperature range	Tj = −65°C to +150°C enables deployment in automotive engine compartments and industrial enclosures.

Applications

Switch-Mode Power Supply Output Rectifier

IGBT Freewheeling Diode

Use Scenario: Used in secondary-side rectification of 100–300 W offline flyback and forward converters.

IC Role / Device Role / Timing Role: Ultrafast diode conducting during transformer reset phase; blocks reverse voltage during primary switch conduction.

Use Value: 25 ns trr minimizes dead-time loss and improves efficiency by >1.2% vs. standard fast recovery diodes at 250 kHz.

Use Scenario: Mounted across IGBT collector-emitter in three-phase inverter legs for motor drive applications.

IC Role / Device Role / Timing Role: Provides low-loss current path during inductive load commutation; clamps voltage spikes during turn-off.

Use Value: Low Qrr and negligible tail current reduce switching loss and gate driver stress, extending IGBT lifetime.

Transistor Base Drive Clamp

DC-DC Converter Snubber Diode

Use Scenario: Placed across BJT or MOSFET base/gate drive transformer secondaries to suppress ringing.

IC Role / Device Role / Timing Role: Fast turn-on clamps overshoot; rapid turn-off prevents latch-up during high-dI/dt transitions.

Use Value: 75 ns tfr and 7.0 V VFP limit voltage excursion to <12 V, protecting drive ICs and ensuring reliable switching.

Use Scenario: Integrated into RCD snubber networks across MOSFETs in isolated DC-DC modules (e.g., 48 V input telecom supplies).

IC Role / Device Role / Timing Role: Absorbs leakage inductance energy during MOSFET turn-off; recirculates current before capacitor recharge.

Use Value: 16 ns typical trr ensures snubber action completes within 30 ns, preventing voltage doubling and MOSFET avalanche.

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultrafast diode applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH3L04	TO-220AC package, VF = 1.25 V @ 3 A/100°C, trr = 22 ns, higher thermal mass	Suitable for higher-power, heatsink-mounted designs; not axial-compatible	Select when board space allows TO-220 mounting and lower VF is prioritized over lead-form flexibility.
UF4004	DO-41 package, VRRM = 400 V, IF(AV) = 1 A, trr = 50 ns, VF = 1.5 V @ 1 A	Limited to ≤1 A average current; slower recovery increases switching loss above 100 kHz	Acceptable only in low-current (<1 A), lower-frequency (<100 kHz) cost-sensitive designs where trr margin is acceptable.

Compared with STTH3L04 and UF4004, BYT03-400 uniquely balances axial DO-201AD form factor, 3 A rating, and 25 ns trr - making it optimal for space-constrained, medium-power, high-frequency freewheeling and snubbing where leaded mechanical fit and dynamic performance are jointly critical.

Availability

BYT03-400 is available at Aetrix Electronics and suitable for switch-mode power supplies, IGBT motor drives, and DC-DC converter snubbers requiring stable component supply, long-lifecycle availability, and consistent parametric performance across production batches.

Supply support for BYT03-400 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.

BYT03-400 belongs to ST's ultrafast diode product line, engineered specifically for high-efficiency, high-frequency power conversion where low trr, low VF, and rugged surge capability are essential in compact axial packages.

FAQ

What is the maximum junction temperature and how does it affect derating?

The BYT03-400 has a maximum operating junction temperature of 150°C. Derating begins at ambient temperatures above 55°C, where average forward current must be reduced per Fig. 2 in the datasheet - e.g., to ~2.2 A at 85°C ambient with δ = 0.5 and standard PCB mounting. Thermal resistance (Rth(j-a) = 20 °C/W on infinite heatsink) defines the required heatsinking for safe operation.

Can BYT03-400 replace standard fast recovery diodes in existing designs?

Yes, provided the design operates below 3 A average current and requires trr ≤25 ns. Its DO-201AD footprint matches many legacy fast recovery diodes (e.g., BYW29-200), but verify layout clearance for 400 V VRRM and confirm that 60 A IFSM meets surge requirements - especially in inductive load switching where peak current exceeds average.

How does forward recovery voltage (VFP) impact gate drive protection?

VFP reaches 7.0 V at 3 A and high dIF/dt, which can exceed logic-level gate thresholds. When used in base/gate drive clamping, this limits voltage overshoot to safe levels for drivers like UC384x or IR2110, preventing false triggering or latch-up - confirmed by Fig. 8 showing VFP remains <7.5 V even at dIF/dt = 100 A/µs.

Is BYT03-400 suitable for automotive under-hood applications?

Yes - its −65°C to +150°C storage and operating temperature range, UL 94 V0 epoxy, and robust surge rating (60 A IFSM) meet baseline requirements for non-safety-critical automotive power modules. However, it is not AEC-Q101 qualified; for certified automotive use, ST's AEC-Q101 ultrafast diodes (e.g., STTH3R04-Y) should be selected instead.

BYT03-400 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: DO-201AD, Axial

Packaging:: Tape & Box (TB)

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):: 55 ns

Current - Reverse Leakage @ Vr:: 20 µA @ 400 V

Capacitance @ Vr, F:: -

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-201AD

Operating Temperature - Junction:: 150°C (Max)

BYT03-400 FAQ

1.How can I place an order for BYT03-400 through Aetrix?

Please submit a Request for Quotation (RFQ) for BYT03-400 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 BYT03-400 reliable?

The price and inventory of BYT03-400 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BYT03-400 is usually 5 days.

3.What payment methods are accepted for BYT03-400?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BYT03-400 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BYT03-400?

BYT03-400 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BYT03-400 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 BYT03-400?

For technical support, including BYT03-400 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BYT03-400 requirements.

6.How does Aetrix verify that BYT03-400 is sourced from the original manufacturer or authorized distributors?

All BYT03-400 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 BYT03-400 meets industry standards.

7.What is the process for return or replacement of BYT03-400?

All BYT03-400 units undergo pre-shipment inspection (PSI). If there is an issue with BYT03-400, 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 BYT03-400 part is unused and in its original packaging.

Return procedure for BYT03-400:

1.Submit a request within 90 days.

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

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