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STMicroelectronics STTH803D
- Part No.:
- STTH803D
- Manufacturer:
- STMicroelectronics
- Category:
- Single Diodes
- Package:
- TO-220-2
- Datasheet:
-
STTH803D.pdf
- Description:
- DIODE GEN PURP 300V 8A TO220AC
- Quantity:
- Payment:
- Shipping:
Inventory:761
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Product details
Overview
STTH803D from STMicroelectronics is a single ultra-fast recovery epitaxial rectifier diode in TO-220AC package, rated for 300 V repetitive peak reverse voltage, 8 A average forward current, and 25 ns maximum reverse recovery time. It serves as secondary-side rectifier in high-frequency switch-mode power supplies and DC/DC converters operating up to several hundred kHz.
For engineers reviewing the STTH803D datasheet, STTH803D pinout, STTH803D application, or STTH803D equivalent, key selection criteria include soft recovery (Sfactor ≥0.3), low conduction loss (VF typ. 0.85 V at 125 °C), thermal resistance (Rth(j-c) = 2.5 °C/W), and ECOPACK®2 compliance for industrial-grade power conversion designs.
Technical Context
This diode employs an epitaxial structure optimized for fast, soft reverse recovery-critical for minimizing EMI and switching losses in synchronous and quasi-resonant topologies. Its trr ≤25 ns at IF = 0.5 A with Irr/IF = 0.5 and dlF/dt = −50 A/µs ensures clean turn-off behavior under hard-switching conditions.
Thermal performance is defined by Rth(j-c) = 2.5 °C/W and Tj(max) = 175 °C, enabling reliable operation at high ambient temperatures when mounted on heatsinks with proper torque (0.55 N·m recommended). Conduction loss follows P = 0.75 × IF(AV) + 0.031 × IF²(RMS).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 300 V - supports 24–48 V output SMPS with 2× safety margin against transient spikes |
| IF(AV) | 8 A - delivers continuous DC output current in 100–300 W secondary rectification stages |
| trr (max) | 25 ns - enables stable operation up to ~500 kHz switching frequency without excessive ringing |
| VF (typ) | 0.85 V at 125 °C - reduces conduction loss by ~15% vs. standard FRDs at elevated junction temperature |
| Rth(j-c) | 2.5 °C/W - allows 50 °C temperature rise at 20 W dissipation with minimal heatsink requirement |
| Sfactor | ≥0.3 - suppresses voltage overshoot and EMI during reverse recovery in flyback and LLC converters |
| IRM | 8 A - limits peak reverse recovery current to prevent MOSFET stress in synchronous rectifier gate drive circuits |
Pinout & Package
STTH803D uses the TO-220AC package: 3-pin, single-ended anode-cathode configuration with isolated metal tab (cathode-connected). Mounting requires 0.55 N·m torque and thermal interface material for optimal heat transfer.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Input terminal for forward conduction path | Connected to transformer secondary winding or switching node; carries full load current during ON-state |
| Cathode (Pin 2) | Output terminal for forward conduction path | Connected to output capacitor and load; electrically tied to metal tab for thermal conduction |
| Metal Tab (Cathode) | Thermal & electrical cathode connection | Provides low-inductance, low-resistance cathode return path and primary heat dissipation route to heatsink |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-fast soft recovery | trr ≤25 ns with Sfactor ≥0.3 - minimizes switching noise and snubber losses in high-frequency converters |
| High-temperature operation | Tj(max) = 175 °C - sustains full-rated current in compact, sealed power supplies without derating |
| Low forward voltage | VF = 0.85 V (typ.) at 125 °C - improves efficiency by reducing I²R losses in 12–48 V output rails |
| ECOPACK®2 compliance | Halogen-free, RoHS-compliant epoxy - meets industrial and telecom environmental requirements without performance trade-offs |
Applications
| Server PSU Secondary Rectification | Industrial DC/DC Converter |
|---|---|
Use Scenario: 48 V output stage in 80 PLUS Titanium server power supply operating at 300 kHz. IC Role / Device Role / Timing Role: Fast-recovery rectifier replacing Schottky diodes where higher VRRM and lower leakage are required. Use Value: Enables 96%+ efficiency at full load while maintaining <10 mVpp output ripple due to soft recovery and low IR. | Use Scenario: 24 V isolated DC/DC module for PLC I/O power distribution in factory automation. IC Role / Device Role / Timing Role: Secondary-side freewheeling diode in forward converter topology with 150 kHz switching. Use Value: Eliminates need for active clamp circuitry by limiting VFR to 3.5 V and suppressing dv/dt-induced shoot-through. |
| Telecom Brick Power Supply | Medical Imaging Power Module |
Use Scenario: 12 V/10 A output in half-brick telecom power supply with strict EMI Class B limits. IC Role / Device Role / Timing Role: High-frequency rectifier in asymmetrical half-bridge secondary with synchronous rectification assist. Use Value: Reduces conducted EMI by >6 dBμV via soft recovery (Sfactor ≥0.3), easing filter design and board space. | Use Scenario: Auxiliary 5 V/3 A bias supply in MRI gradient amplifier subsystem requiring zero failure risk. IC Role / Device Role / Timing Role: Isolated secondary rectifier with guaranteed 175 °C junction rating for long-term reliability. Use Value: Supports 15-year field life under continuous 60 °C ambient with no VF drift or IR increase beyond spec. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fast recovery rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STTH8R03DJ | D²PAK package, same VRRM/trr/VF specs, but 1.38 g weight and tape-and-reel packaging | Better suited for automated SMT assembly; slightly higher Rth(j-c) (3.0 °C/W) | Select when surface-mount integration and high-volume pick-and-place are required |
| IXYS MUR830E | TO-220AC, 300 V, 8 A, trr = 35 ns (max), VF = 1.3 V (typ. at 25 °C) | Higher VF increases conduction loss by ~20%; slower recovery raises EMI risk above 200 kHz | Acceptable only in cost-sensitive, lower-frequency (<150 kHz) designs where thermal margin exists |
Compared with STTH803D, STTH8R03DJ offers identical electrical performance in a surface-mount package ideal for automated production, while IXYS MUR830E trades off speed and forward drop for legacy compatibility-making STTH803D optimal for new high-efficiency, high-frequency designs.
Availability
STTH803D is available at Aetrix Electronics and suitable for server power supplies, industrial DC/DC converters, telecom brick modules, and medical imaging power systems requiring stable component supply and long-term manufacturability.
Supply support for STTH803D 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 microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer markets.
STTH803D belongs to ST's high-voltage fast recovery diode product line, engineered specifically for high-efficiency, high-frequency secondary rectification in switched-mode power conversion systems.
FAQ
What is the maximum junction temperature and how does it affect derating?
The STTH803D has a maximum junction temperature of 175 °C. At TC = 150 °C, its IF(AV) remains rated at 8 A. Derating begins only above that case temperature-e.g., at TC = 160 °C, IF(AV) drops to ~6.5 A per the datasheet curve. This allows full-rated operation in thermally constrained enclosures without external cooling.
Is the metal tab electrically isolated or connected to a specific terminal?
The metal tab of the STTH803D in TO-220AC package is electrically connected to the cathode (Pin 2) and must be insulated from the heatsink unless the cathode node is at chassis ground potential. ST specifies isolation voltage of 2500 V RMS between tab and leads, verified per UL 94 V0 epoxy standards.
How does soft recovery reduce EMI in high-frequency converters?
Soft recovery (Sfactor ≥0.3) means reverse current decays gradually rather than abruptly, limiting di/dt and associated magnetic field transients. In practice, this reduces high-frequency spectral content above 30 MHz by 6–10 dB, easing compliance with CISPR 22/32 Class B conducted EMI limits without oversized filters.
Can STTH803D replace Schottky diodes in 48 V output applications?
Yes-where VRRM > 200 V is needed and leakage must be minimized. Unlike Schottkys, STTH803D maintains IR < 200 µA at 125 °C and 300 V, avoiding thermal runaway in hot environments. Its VF is higher (~0.85 V vs. ~0.5 V), but trr advantage enables cleaner switching above 200 kHz where Schottky parasitic capacitance causes losses.
STTH803D 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):
- 300 V
- Current - Average Rectified (Io):
- 8A
- Voltage - Forward (Vf) (Max) @ If:
- 1.25 V @ 8 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 35 ns
- Current - Reverse Leakage @ Vr:
- 20 µA @ 300 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220AC
- Operating Temperature - Junction:
- 175°C (Max)
STTH803D FAQ
1.How can I place an order for STTH803D through Aetrix?
Please submit a Request for Quotation (RFQ) for STTH803D 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 STTH803D reliable?
The price and inventory of STTH803D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STTH803D is usually 5 days.
3.What payment methods are accepted for STTH803D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STTH803D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STTH803D?
STTH803D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STTH803D 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 STTH803D?
For technical support, including STTH803D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STTH803D requirements.
6.How does Aetrix verify that STTH803D is sourced from the original manufacturer or authorized distributors?
All STTH803D 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 STTH803D meets industry standards.
7.What is the process for return or replacement of STTH803D?
All STTH803D units undergo pre-shipment inspection (PSI). If there is an issue with STTH803D, 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 STTH803D part is unused and in its original packaging.
Return procedure for STTH803D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STTH803D Tags
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