Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Taiwan Semiconductor Corporation MUR440S

Name: MUR440S
Brand: Taiwan Semiconductor Corporation
SKU: MUR440S
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: MUR440S

Manufacturer:: Taiwan Semiconductor Corporation

Category:: Single Diodes

Package:: DO-214AB, SMC

Datasheet:: MUR440S.pdf

Description:: DIODE GEN PURP 400V 4A DO214AB

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:2,883

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

MUR440S from Taiwan Semiconductor is an ultra-fast recovery surface-mount rectifier diode with 4 A average forward current, 400 V repetitive peak reverse voltage, and 50 ns reverse recovery time; it uses a glass-passivated junction in DO-214AB (SMC) package and is designed for high-frequency switching-mode power supplies in telecom and computing systems.

For engineers reviewing the MUR440S datasheet, MUR440S pinout, MUR440S application, or MUR440S equivalent, key selection criteria include its 400 V V_RRM, 50 ns trr, 1.25 V max VF at 4 A/25°C, thermal resistance R_θJC = 8.5 °C/W, and DO-214AB mechanical compatibility with automated SMT assembly.

Technical Context

The MUR440S is a single-die, unidirectional silicon rectifier optimized for high-efficiency DC-DC conversion where fast switching minimizes switching losses. Its 50 ns reverse recovery time enables operation at frequencies up to several hundred kHz without excessive ringing or EMI.

Thermally, it supports continuous operation up to 175 °C junction temperature with R_θJA = 45 °C/W (on standard FR-4 PCB) and R_θJC = 8.5 °C/W, allowing direct heatsinking via the cathode tab in high-power density designs.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	400 V - maximum non-repetitive reverse blocking voltage; defines safe operating limit in flyback or boost topologies
I_F	4 A - average forward current rating at T_C = 110 °C; determines continuous conduction capability
t_rr	50 ns - measured at I_F = 0.5 A, I_R = 1.0 A, I_rr = 0.25 A; enables efficient operation in >200 kHz SMPS
V_F (max)	1.25 V @ 4 A, 25 °C - forward voltage drop directly impacts conduction loss and thermal design
R_θJC	8.5 °C/W - junction-to-case thermal resistance; enables thermal management via metalized PCB pad or heatsink contact
I_FSM	75 A - peak surge current for 8.3 ms half-sine; supports inrush and transient overload handling
C_J	65 pF @ 1 MHz, 4 V - junction capacitance affects high-frequency switching noise and snubber sizing

Pinout & Package

Package: DO-214AB (SMC), surface-mount, molded plastic case with matte tin-plated leads; polarity indicated by cathode band; meets UL 94V-0 and JESD201 Class 2 whisker requirements.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry point	Connected to lower-potential side of circuit (e.g., transformer secondary or switch node)
Cathode	Forward current exit / reverse blocking terminal	Connected to output rail; tab serves as primary thermal path and must be soldered to copper pour

Key Features

Feature	Design Value
Glass passivated junction	Enhances long-term reliability under humidity and thermal cycling; eliminates need for conformal coating in industrial environments
Ultra-fast 50 ns recovery	Reduces switching loss and EMI generation in high-frequency converters (e.g., 300–500 kHz telecom PSUs)
DO-214AB (SMC) package	Supports automated pick-and-place; 7.1 mm × 6.2 mm footprint enables compact layout with low parasitic inductance
Moisture sensitivity level 1	Eliminates bake requirement prior to reflow; compatible with standard J-STD-020 profile
RoHS & halogen-free	Complies with IEC 61249-2-21; suitable for export to EU, Japan, and other regulated markets

Applications

Server Power Supply	Telecom DC-DC Converter
Use Scenario: Secondary-side rectification in 48 V input, 12 V/54 A isolated forward converter for rack-mounted servers. IC Role / Device Role / Timing Role: Ultra-fast freewheeling diode replacing synchronous MOSFETs where cost and control complexity are constraints. Use Value: 50 ns t_rr reduces voltage overshoot and snubber losses, enabling stable 350 kHz operation without added gate drive circuitry.	Use Scenario: Output rectification in 36–72 V telecom brick supplying 3.3 V/20 A to baseband processing boards. IC Role / Device Role / Timing Role: High-efficiency unidirectional current path with minimal conduction and switching loss trade-off. Use Value: 1.25 V V_F at full load and 8.5 °C/W R_θJC allow direct thermal coupling to chassis, reducing heatsink volume by ~30% vs. slower alternatives.
Industrial Motor Drive	LED Driver Power Stage
Use Scenario: Freewheeling path across IGBTs in 24 V/10 A H-bridge for servo actuator control. IC Role / Device Role / Timing Role: Clamp diode absorbing inductive kickback during PWM dead-time intervals. Use Value: 75 A I_FSM withstands motor stall currents; 50 ns t_rr prevents cross-conduction risk during fast switching transitions.	Use Scenario: Primary rectification in 120 VAC input, constant-current LED driver for street lighting. IC Role / Device Role / Timing Role: Bridge input diode handling 4 A RMS in full-wave configuration with high ripple frequency. Use Value: Glass passivation ensures stable leakage (<10 μA @ 400 V) over 10-year outdoor deployment; DO-214AB withstands vibration per IEC 60068-2-6.

Server Power Supply

Telecom DC-DC Converter

Use Scenario: Secondary-side rectification in 48 V input, 12 V/54 A isolated forward converter for rack-mounted servers.

IC Role / Device Role / Timing Role: Ultra-fast freewheeling diode replacing synchronous MOSFETs where cost and control complexity are constraints.

Use Value: 50 ns t_rr reduces voltage overshoot and snubber losses, enabling stable 350 kHz operation without added gate drive circuitry.

Use Scenario: Output rectification in 36–72 V telecom brick supplying 3.3 V/20 A to baseband processing boards.

IC Role / Device Role / Timing Role: High-efficiency unidirectional current path with minimal conduction and switching loss trade-off.

Use Value: 1.25 V V_F at full load and 8.5 °C/W R_θJC allow direct thermal coupling to chassis, reducing heatsink volume by ~30% vs. slower alternatives.

Industrial Motor Drive

LED Driver Power Stage

Use Scenario: Freewheeling path across IGBTs in 24 V/10 A H-bridge for servo actuator control.

IC Role / Device Role / Timing Role: Clamp diode absorbing inductive kickback during PWM dead-time intervals.

Use Value: 75 A I_FSM withstands motor stall currents; 50 ns t_rr prevents cross-conduction risk during fast switching transitions.

Use Scenario: Primary rectification in 120 VAC input, constant-current LED driver for street lighting.

IC Role / Device Role / Timing Role: Bridge input diode handling 4 A RMS in full-wave configuration with high ripple frequency.

Use Value: Glass passivation ensures stable leakage (<10 μA @ 400 V) over 10-year outdoor deployment; DO-214AB withstands vibration per IEC 60068-2-6.

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-fast rectifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH4R04	400 V V_RRM, 4 A I_F, 45 ns t_rr, TO-220AC package	Through-hole mounting; higher R_θJA (50 °C/W); no SMT compatibility	Preferred where board space allows through-hole and thermal mass improves surge robustness
ES4D	400 V V_RRM, 4 A I_F, 55 ns t_rr, DO-214AB package, 1.3 V V_F max	Near-identical footprint and polarity; slightly higher forward drop increases conduction loss by ~4%	Suitable for drop-in replacement when minor VF penalty is acceptable and second-source qualification is required

Compared with STTH4R04 and ES4D, the MUR440S offers optimal balance of SMT compatibility, 50 ns recovery, and 1.25 V VF in DO-214AB - making it preferred for space-constrained, high-frequency telecom and server power designs requiring automated assembly.

Availability

MUR440S is available at Aetrix Electronics and suitable for telecom power supplies, server DC-DC converters, and industrial motor drives requiring stable component supply, RoHS-compliant sourcing, and consistent DO-214AB packaging.

Supply support for MUR440S 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in rectifiers, TVS diodes, MOSFETs, and bipolar transistors.

The MUR440S belongs to TSC's MUR4xS ultra-fast rectifier family, engineered specifically for high-efficiency, high-frequency AC/DC and DC/DC conversion in computing, telecom, and industrial power systems.

FAQ

What is the maximum junction temperature rating for the MUR440S?

The MUR440S has a maximum junction temperature (T_J) rating of +175 °C, verified per absolute maximum ratings table. This allows reliable operation in high-ambient environments such as enclosed server power supplies or industrial enclosures. Derating curves in the datasheet confirm usable current capacity down to T_C = 110 °C for 4 A continuous conduction. Thermal design must respect R_θJC = 8.5 °C/W and ensure adequate copper area under the cathode tab.

Does the MUR440S have a specified moisture sensitivity level (MSL)?

Yes, the MUR440S is rated MSL Level 1 per J-STD-020, meaning it is not moisture-sensitive and requires no baking before reflow soldering. This simplifies manufacturing flow and eliminates floor-life tracking. The device's DO-214AB (SMC) package uses moisture-resistant molding compound, and its matte tin-plated leads meet J-STD-002 solderability requirements.

How does the forward voltage of the MUR440S compare at different temperatures?

At 4 A and 25 °C, the MUR440S has a maximum forward voltage (V_F) of 1.25 V; at 4 A and 150 °C, V_F drops to 1.05 V max. This negative temperature coefficient improves thermal stability in parallel configurations and reduces conduction loss at elevated operating temperatures typical in sealed power modules.

Is the MUR440S pin-compatible with other devices in the MUR4xS series?

Yes, all MUR4xS variants-including MUR420S, MUR440S, and MUR460S-share identical DO-214AB (SMC) package dimensions, pinout, and thermal characteristics. Only V_RRM and related parameters (e.g., reverse leakage, recovery time) differ. This allows design reuse across voltage grades without PCB layout changes.

What is the reverse recovery time test condition for the MUR440S?

The MUR440S reverse recovery time (t_rr) is specified as 50 ns under conditions: I_F = 0.5 A, I_R = 1.0 A, I_rr = 0.25 A, with measurement per JEDEC standard test circuit (Fig.6). This reflects real-world switching behavior in hard-commutated converters and validates suitability for >200 kHz operation without excessive switching loss.

MUR440S Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Series:: -

Package/Case:: DO-214AB, SMC

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Standard

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

Current - Average Rectified (Io):: 4A

Voltage - Forward (Vf) (Max) @ If:: -

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

Reverse Recovery Time (trr):: 50 ns

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

Capacitance @ Vr, F:: 65pF @ 4V, 1MHz

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: DO-214AB (SMC)

Operating Temperature - Junction:: -55°C ~ 175°C

MUR440S FAQ

1.How can I place an order for MUR440S through Aetrix?

Please submit a Request for Quotation (RFQ) for MUR440S 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 MUR440S reliable?

The price and inventory of MUR440S are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MUR440S is usually 5 days.

3.What payment methods are accepted for MUR440S?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MUR440S transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MUR440S?

MUR440S orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MUR440S 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 MUR440S?

For technical support, including MUR440S datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MUR440S requirements.

6.How does Aetrix verify that MUR440S is sourced from the original manufacturer or authorized distributors?

All MUR440S 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 MUR440S meets industry standards.

7.What is the process for return or replacement of MUR440S?

All MUR440S units undergo pre-shipment inspection (PSI). If there is an issue with MUR440S, 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 MUR440S part is unused and in its original packaging.

Return procedure for MUR440S:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…