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

STMicroelectronics STTH8R04D

Name: STTH8R04D
Brand: STMicroelectronics
SKU: STTH8R04D
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STTH8R04D

Manufacturer:: STMicroelectronics

Category:: Single Diodes

Package:: TO-220-2

Datasheet:: STTH8R04D.pdf

Description:: DIODE GEN PURP 400V 8A TO220AC

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Product details

Overview

STTH8R04D from STMicroelectronics is a 400 V, 8 A ultrafast recovery diode in TO-220AC package, featuring 25 ns typical reverse recovery time (trr), 0.9 V typical forward voltage (VF) at 25 °C, and 175 °C maximum junction temperature. It is engineered for low-voltage, high-frequency inverters, freewheeling paths, and polarity protection circuits in industrial power supplies and motor drives.

For engineers reviewing the STTH8R04D datasheet, STTH8R04D pinout, STTH8R04D application, or STTH8R04D equivalent, key selection criteria include trr ≤ 35 ns at 125 °C, VF ≤ 1.30 V at 100 °C/8 A, Rth(j-c) = 2.5 °C/W, insulated mounting capability, and ECOPACK®2 compliance for surface-mount alternatives.

Technical Context

This diode employs ST's planar platinum doping technology to achieve ultrafast soft recovery with S-factor ≥ 0.4, minimizing EMI and voltage overshoot during commutation. Its dynamic performance is characterized under controlled dIF/dt conditions (up to –200 A/µs) and reverse voltages up to 320 V.

The device operates across –40 °C to +175 °C junction temperature range and supports pulsed forward currents up to 165 A (tp = 10 µs). Thermal design relies on conduction cooling via the case, with validated Rth(j-c) of 2.5 °C/W for TO-220AC and 5.5 °C/W for insulated variant.

Key Specifications

Parameter	Value and Actual Design Meaning
VRRM	400 V - Maximum repetitive reverse blocking voltage without breakdown
IF(AV)	8 A - Average forward current at TC = 145 °C, defining continuous conduction capability
trr (typ)	25 ns - Typical reverse recovery time at IF = 1 A, dIF/dt = –100 A/µs, VR = 30 V
VF (typ)	0.9 V - Typical forward voltage drop at IF = 8 A, Tj = 25 °C, directly impacting conduction loss
Tj (max)	+175 °C - Maximum allowable junction temperature, enabling operation in high-ambient environments
Rth(j-c)	2.5 °C/W - Junction-to-case thermal resistance for TO-220AC, critical for heatsink sizing
IRM (max)	8.0 A - Peak reverse recovery current at IF = 8 A, dIF/dt = –200 A/µs, VR = 320 V, Tj = 125 °C

Pinout & Package

STTH8R04D uses the TO-220AC through-hole package with electrically isolated tab (non-insulated version), where Pin 1 is Anode and Pin 2 is Cathode. The metal tab is connected to the cathode and serves as the primary thermal path.

Pin/Terminal	Circuit Role	Design Meaning
Anode (Lead 1)	Forward current entry terminal	Connected to positive side of switching node; must withstand peak forward surge (IFSM = 120 A)
Cathode (Lead 2)	Forward current exit / reverse blocking terminal	Electrically tied to metal tab; requires insulated mounting if referenced to non-ground potential
Tab (Cathode)	Thermal interface & electrical cathode connection	Provides low-impedance heat transfer path (Rth(j-c) = 2.5 °C/W); mounting torque: 0.55 N·m (max 0.70 N·m)

Key Features

Feature	Design Value
Ultrafast soft recovery	S-factor ≥ 0.4 ensures low EMI and reduced voltage ringing during turn-off
High-temperature operation	Rated for continuous operation up to Tj = +175 °C, supporting compact thermal designs
Low conduction loss	VF = 0.9 V (typ) at 8 A/25 °C enables <1.5 W conduction loss in typical 12 V–48 V DC/DC stages
ECOPACK®2 compliance	Meets RoHS and halogen-free requirements without compromising thermal or electrical performance
High pulsed current capability	IFRM = 165 A (tp = 10 µs) supports robust operation in hard-switched SMPS and IGBT snubbers

Applications

Industrial Motor Drives

Server Power Supplies

Use Scenario: Freewheeling path in 3-phase IGBT inverter stages driving 0.5–5 kW AC induction motors.

IC Role / Device Role / Timing Role: Ultrafast cathode-connected freewheeling diode clamping inductive kickback during IGBT turn-off.

Use Value: 25 ns trr minimizes cross-conduction risk and reduces switching losses by >15% vs. standard fast recovery diodes.

Use Scenario: Output rectification in 48 V input, 12 V/50 A LLC resonant DC/DC converters for AI server racks.

IC Role / Device Role / Timing Role: High-frequency synchronous rectifier replacement in secondary-side unidirectional conduction path.

Use Value: 0.9 V VF at 8 A lowers conduction loss by ~0.3 W per diode versus 1.15 V alternatives, improving full-load efficiency by 0.4%.

Solar Microinverters

Automotive DC-DC Converters

Use Scenario: Boost stage output rectification in single-phase 250–300 W microinverters interfacing with 30–60 V PV strings.

IC Role / Device Role / Timing Role: 400 V-rated output diode handling high dIF/dt (>100 A/µs) during MPPT transients.

Use Value: Soft recovery (S-factor ≥ 0.4) suppresses EMI peaks above 30 MHz, easing EMC filter design and reducing BOM cost.

Use Scenario: Polarity protection in 12 V/24 V automotive DC-DC modules powering ADAS camera systems.

IC Role / Device Role / Timing Role: Reverse-voltage blocking element placed upstream of LDOs and PMICs to prevent battery reversal damage.

Use Value: 175 °C Tj(max) ensures reliable operation under hood temperatures up to +125 °C ambient with derated current.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH8R04DI	TO-220AC Ins package with 2500 VRMS isolation; identical electrical specs	Required where cathode tab must be electrically isolated from heatsink or chassis ground	Select when system-level isolation rating >1500 VRMS is mandated (e.g., medical, isolated DC/DC)
IXYS MUR840E	400 V, 8 A, trr = 35 ns (typ), VF = 1.05 V (typ) at 8 A/25 °C, TO-220AC	Higher trr and VF increase switching/conduction losses; not ECOPACK®2 compliant	Acceptable for cost-sensitive, non-automotive designs where 5–10 ns trr margin is acceptable

Compared with STTH8R04D, STTH8R04DI adds insulation without sacrificing speed or thermal performance, while MUR840E trades 10 ns slower recovery and higher VF for broader distributor availability-making STTH8R04D optimal for thermally constrained, high-efficiency, and environmentally regulated designs.

Availability

STTH8R04D is available at Aetrix Electronics and suitable for industrial motor drives, server power supplies, solar microinverters, and automotive DC-DC converters requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for STTH8R04D 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, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and power applications since 1987.

STTH8R04 belongs to ST's ultrafast recovery diode product line, developed specifically for high-frequency switching topologies demanding low trr, soft recovery, and high-temperature reliability in power conversion stages.

FAQ

Is STTH8R04D pin-compatible with STTH8R04DI?

No. While both share identical electrical characteristics and TO-220AC outline, STTH8R04DI features an insulated tab requiring different mounting hardware and thermal interface design. Mechanical mounting holes and creepage distances differ, and the insulated variant cannot substitute directly without PCB and heatsink redesign.

What is the maximum recommended mounting torque for STTH8R04D?

The recommended torque value is 0.55 N·m, with an absolute maximum of 0.70 N·m. Exceeding this risks mechanical damage to the leadframe or internal bond wires, potentially degrading thermal resistance or causing premature failure under thermal cycling.

Can STTH8R04D be used in synchronous rectification topologies?

No. STTH8R04D is a unidirectional, non-controlled diode with no gate terminal. It cannot replace MOSFET-based synchronous rectifiers. However, it serves as a high-performance alternative to Schottky diodes in 400 V-class applications where Schottky leakage or voltage rating limits apply.

Does STTH8R04D require a heatsink in all applications?

Yes, for continuous IF(AV) = 8 A operation. At TC = 145 °C, junction temperature reaches 175 °C only with adequate heatsinking achieving ≤2.5 °C/W total thermal resistance (including interface and ambient). Without a heatsink, average current must be limited to ≤1.5 A to avoid thermal runaway.

STTH8R04D Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-2

Packaging:: Tube

Product Status:: Active

Technology:: Standard

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

Current - Average Rectified (Io):: 8A

Voltage - Forward (Vf) (Max) @ If:: 1.5 V @ 8 A

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

Reverse Recovery Time (trr):: 50 ns

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

Capacitance @ Vr, F:: -

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220AC

Operating Temperature - Junction:: -40°C ~ 175°C

STTH8R04D FAQ

1.How can I place an order for STTH8R04D through Aetrix?

Please submit a Request for Quotation (RFQ) for STTH8R04D 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 STTH8R04D reliable?

The price and inventory of STTH8R04D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STTH8R04D is usually 5 days.

3.What payment methods are accepted for STTH8R04D?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STTH8R04D transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STTH8R04D?

STTH8R04D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STTH8R04D 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 STTH8R04D?

For technical support, including STTH8R04D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STTH8R04D requirements.

6.How does Aetrix verify that STTH8R04D is sourced from the original manufacturer or authorized distributors?

All STTH8R04D 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 STTH8R04D meets industry standards.

7.What is the process for return or replacement of STTH8R04D?

All STTH8R04D units undergo pre-shipment inspection (PSI). If there is an issue with STTH8R04D, 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 STTH8R04D part is unused and in its original packaging.

Return procedure for STTH8R04D:

1.Submit a request within 90 days.

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

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