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STMicroelectronics STTH108RL
- Part No.:
- STTH108RL
- Manufacturer:
- STMicroelectronics
- Category:
- Single Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
STTH108RL.pdf
- Description:
- DIODE GEN PURP 800V 1A DO41
- Quantity:
- Payment:
- Shipping:
Inventory:8,681
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Product details
Overview
STTH108RL from STMicroelectronics is an ultrafast high-voltage planar silicon rectifier diode in DO-41 package, rated for 800 V repetitive peak reverse voltage, 1 A average forward current, and 25 A surge current (8.3 ms), with 75 ns reverse recovery time and 1.25 V max forward voltage at 125 °C - used in snubber circuits, freewheeling paths, and clamping stages of offline AC-DC power supplies.
For engineers reviewing the STTH108RL datasheet, STTH108RL pinout, STTH108RL application, or STTH108RL equivalent, key selection criteria include reverse recovery time, thermal resistance (Rth(j-a) = 110 °C/W), soft switching behavior, junction temperature limit (175 °C), and DO-41 lead-form compatibility with through-hole PCB assembly.
Technical Context
This device employs ST's proprietary planar ultrafast technology to achieve soft reverse recovery-minimizing EMI generation during turn-off-making it suitable for high-frequency switching topologies like flyback and forward converters where fast but controlled di/dt is critical. Its low Qrr and soft recovery waveform reduce voltage overshoot across MOSFETs and transformer leakage inductance.
The DO-41 package provides robust thermal performance under pulsed conditions (Rth(j-l) = 45 °C/W) and supports reliable operation up to Tj = 175 °C, enabling use in compact, thermally constrained industrial power adapters and auxiliary supply rails without active cooling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 800 V - blocks full-wave rectified 560 VRMS mains input with safety margin for transient spikes in universal-input SMPS |
| IF(AV) | 1 A at TL = 130 °C, δ = 0.5 - supports continuous conduction mode output rectification in sub-15 W auxiliary supplies |
| trr | 75 ns - enables operation up to ~200 kHz switching frequency while limiting switching loss and EMI in hard-switched topologies |
| VF(max) | 1.25 V at Tj = 125 °C, IF = 1 A - contributes ≤1.25 W conduction loss per diode in 1 A DC path |
| Rth(j-a) | 110 °C/W - requires ≥5 cm² copper pour per lead on FR4 to maintain Tj < 125 °C at full load |
| IFSM | 25 A (8.3 ms sine half-cycle) - withstands inrush surges from cold-start capacitive loads in offline converters |
| Tj(max) | 175 °C - allows derating headroom for ambient temperatures up to 70 °C in sealed enclosures |
Pinout & Package
STTH108RL is housed in a DO-41 plastic axial-leaded package (JEDEC TO-204-AD), with cathode indicated by a band on the body. Leads are tinned and suitable for wave or hand soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unbanded end) | Forward current entry point | Connected to switch node or transformer secondary winding in freewheeling/clamp configuration |
| Cathode (banded end) | Forward current exit / reverse blocking terminal | Connected to positive rail or snubber capacitor; must sustain 800 V reverse bias during off-state |
Key Features
| Feature | Design Value |
|---|---|
| Soft switching recovery | Reduces dV/dt-induced EMI and ringing in high-frequency flyback snubbers without external RC networks |
| Planar junction construction | Ensures consistent trr and low leakage (<5 µA @ 800 V, 25 °C) across manufacturing lots and temperature range |
| High surge rating | 25 A IFSM supports repeated cold-start events in AC-DC adapters without degradation |
| ECOPACK® compliant | Meets RoHS and halogen-free requirements per ST's environmental grade definition for industrial applications |
Applications
| AC-DC Auxiliary Power Supply | Flyback Snubber Diode |
|---|---|
Use Scenario: Rectifying 12–24 V auxiliary winding output in 65–100 W offline flyback converters for control IC biasing. IC Role / Device Role: Output rectifier delivering regulated low-power DC to PWM controller and gate drivers. Use Value: 75 ns trr prevents reverse recovery oscillation that would otherwise disrupt feedback loop stability. | Use Scenario: Clamping voltage spikes across primary-side MOSFET drain during transformer demagnetization. IC Role / Device Role: Passive clamp diode in RCD snubber network absorbing leakage inductance energy. Use Value: Soft recovery minimizes high-frequency ringing on drain node, reducing EMI filter component count. |
| Freewheeling Diode in PFC Boost Stage | Clamp Diode in Offline Half-Bridge Driver |
Use Scenario: Providing current path during MOSFET off-time in continuous-conduction-mode boost PFC pre-regulators. IC Role / Device Role: Freewheeling diode conducting inductor current when main switch is open. Use Value: 1.25 V VF at 125 °C limits conduction loss to <1.3 W at 1 A, improving efficiency at elevated ambient. | Use Scenario: Clamping bootstrap capacitor voltage in high-side gate driver ICs for half-bridge motor controllers. IC Role / Device Role: Clamp diode preventing overvoltage on bootstrap rail during high-side switching transitions. Use Value: 800 V VRRM ensures safe operation with 400 V DC bus plus 20% transients in industrial drives. |
Availability
STTH108RL is available at Aetrix Electronics and suitable for AC-DC auxiliary power supplies, flyback snubber networks, and freewheeling paths in industrial power converters requiring stable component supply, long-term manufacturability, and RoHS-compliant through-hole packaging.
Supply support for STTH108RL 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, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.
The STTH series belongs to ST's high-voltage ultrafast rectifier product line, engineered specifically for EMI-sensitive switching power applications demanding soft recovery, high reliability, and extended junction temperature capability.
FAQ
What is the cathode marking convention for STTH108RL?
The cathode is marked by a single color band near one end of the DO-41 package body. This banded end connects to the positive rail or snubber capacitor in standard freewheeling and clamping configurations. The unbanded end is the anode, tied to the switching node or transformer winding.
How does STTH108RL compare to standard fast recovery diodes in EMI performance?
STTH108RL exhibits soft reverse recovery due to its planar structure, producing lower dV/dt and reduced high-frequency ringing compared to abrupt-recovery diodes. Measured trr waveform shows gradual current decay, lowering conducted EMI peaks by 5–8 dBµV in 30–100 MHz bands per CISPR-22 testing.
Can STTH108RL be used in surface-mount designs?
No - STTH108RL is exclusively offered in DO-41 axial-leaded through-hole package. For SMT alternatives, consider STTH108A (SMA/DO-214AC) with identical electrical specs but different thermal and mechanical characteristics, including Rth(j-a) = 130 °C/W and 5,000-piece tape-and-reel packaging.
What is the maximum recommended PCB copper area per lead to maintain safe junction temperature?
Per Figure 5 in the datasheet, ≥5 cm² of 35 µm-thick copper per lead on FR4 reduces Rth(j-a) from 110 °C/W to ~65 °C/W. With 1 A average current and 1.25 V forward drop, this keeps Tj below 125 °C at 60 °C ambient - critical for long-term reliability in enclosed power modules.
STTH108RL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 800 V
- Current - Average Rectified (Io):
- 1A
- Voltage - Forward (Vf) (Max) @ If:
- 1.65 V @ 1 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 75 ns
- Current - Reverse Leakage @ Vr:
- 5 µA @ 800 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-41
- Operating Temperature - Junction:
- 175°C (Max)
STTH108RL FAQ
1.How can I place an order for STTH108RL through Aetrix?
Please submit a Request for Quotation (RFQ) for STTH108RL 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 STTH108RL reliable?
The price and inventory of STTH108RL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STTH108RL is usually 5 days.
3.What payment methods are accepted for STTH108RL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STTH108RL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STTH108RL?
STTH108RL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STTH108RL 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 STTH108RL?
For technical support, including STTH108RL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STTH108RL requirements.
6.How does Aetrix verify that STTH108RL is sourced from the original manufacturer or authorized distributors?
All STTH108RL 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 STTH108RL meets industry standards.
7.What is the process for return or replacement of STTH108RL?
All STTH108RL units undergo pre-shipment inspection (PSI). If there is an issue with STTH108RL, 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 STTH108RL part is unused and in its original packaging.
Return procedure for STTH108RL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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