My Inquiry
My Account
Diodes Incorporated SD940-T
- Part No.:
- SD940-T
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Diodes
- Package:
- DO-201AD, Axial
- Datasheet:
-
SD940-T.pdf
- Description:
- DIODE SCHOTTKY 40V 9A DO201AD
- Quantity:
- Payment:
- Shipping:
Inventory:9,860
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SD940-T from Diodes Incorporated is a high-current Schottky barrier rectifier in DO-201AD package, rated for 40 V peak repetitive reverse voltage, 9.0 A average forward current at TC = 120°C, and 340 A non-repetitive surge current. It delivers low forward voltage drop (0.42 V at 9.0 A, TJ = 125°C) and features guard ring protection for transient immunity-used in high-efficiency AC/DC front-end rectification of industrial power supplies.
For engineers reviewing the SD940-T datasheet, SD940-T pinout, SD940-T application, or SD940-T equivalent, key selection criteria include its 40 V VRRM rating, 8.0 K/W junction-to-lead thermal resistance, RoHS-compliant tin-plated leads, and DO-201AD mechanical compatibility with high-power through-hole PCB layouts requiring robust surge handling and low conduction loss.
Technical Context
This Schottky rectifier uses a planar epitaxial structure with integrated guard ring to suppress edge breakdown and improve dv/dt ruggedness up to 10,000 V/µs. Its low VF and high IFSM support high-frequency switching converters where conduction loss minimization and surge resilience are critical.
The device operates across –65°C to +150°C, with thermal resistance RθJL = 8.0 K/W measured under vertical lead mounting (9.5 mm length), enabling direct heat sinking via PCB copper or external heatsink attachment at the cathode lead.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 40 V - Maximum allowable repetitive reverse voltage before avalanche; defines safe blocking range in 36 V nominal input systems. |
| IO @ TC = 120°C | 9.0 A - Continuous DC forward current sustainable at case temperature 120°C with proper heatsinking. |
| IFSM (10 ms) | 340 A - Peak non-repetitive surge current capability; supports inrush limiting in offline SMPS without fuse blow. |
| VF @ 9.0 A, TJ = 125°C | 0.42 V - Low conduction loss reduces power dissipation by ~37% vs. comparable 1N5822 at same current and temperature. |
| RθJL | 8.0 K/W - Thermal resistance from junction to lead; enables direct thermal path to PCB copper pour or chassis mount. |
| CT @ 4 V, 1 MHz | 900 pF - Junction capacitance impacts high-frequency switching noise and EMI filter design in PFC stages. |
Pinout & Package
Package: DO-201AD molded plastic case (UL 94V-0), cathode band polarity marking, tin-plated leads solderable per MIL-STD-202 Method 208.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry point | Connected to AC input or transformer secondary; must handle full load current and surge transients. |
| Cathode | Forward current exit / heat transfer node | Primary thermal path to PCB/heatsink; carries return current and dissipates >95% of device power loss. |
Key Features
| Feature | Design Value |
|---|---|
| Guard ring structure | Suppresses edge breakdown and improves dv/dt immunity to 10,000 V/µs-critical for noisy industrial line inputs. |
| Low VF at high temperature | 0.42 V @ 9.0 A, 125°C ensures stable efficiency in thermally constrained enclosures without derating. |
| High IFSM rating | 340 A surge capacity allows use without parallel devices in 1–2 kW rectifier bridges subject to cold-start surges. |
| RoHS-compliant tin finish | Lead-free termination compatible with standard reflow and wave soldering processes; no post-process plating required. |
Applications
| AC/DC Power Supply Rectification | Industrial Motor Drive Input Stage |
|---|---|
Use Scenario: Full-wave rectification of 36 VAC transformer output feeding a 48 VDC bus in DIN-rail mounted PLC power modules. IC Role / Device Role / Timing Role: High-current Schottky rectifier replacing fast recovery diodes to reduce conduction loss and thermal stress. Use Value: 0.42 V VF at 125°C lowers junction temperature rise by ~12°C vs. legacy 60 V Schottky, extending reliability in sealed enclosures. | Use Scenario: Input stage rectification in 3-phase VFD front-end with unregulated DC link feeding IGBT inverter stage. IC Role / Device Role / Timing Role: Primary AC-to-DC conversion element handling continuous 8 A RMS and 300 A startup surges. Use Value: 340 A IFSM withstands motor locked-rotor surges without degradation, eliminating need for redundant parallel devices. |
| Solar Charge Controller Input Stage | Telecom Rectifier Module |
Use Scenario: PV array input rectification in off-grid MPPT charge controllers accepting up to 60 V open-circuit input. IC Role / Device Role / Timing Role: Reverse-polarity and surge protection rectifier on PV string input before buck converter stage. Use Value: Guard ring design prevents transient-induced failure during lightning-induced line spikes common in outdoor installations. | Use Scenario: -48 V telecom rectifier module converting AC mains to regulated DC for base station power distribution. IC Role / Device Role / Timing Role: High-efficiency output rectifier in phase-shifted full-bridge topology operating at 100 kHz. Use Value: 900 pF junction capacitance limits switching losses and EMI generation compared to higher-C alternatives like SB560. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-current Schottky rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Vishay VS-90SQ040 | Same VRRM (40 V), higher IO (10 A @ TC = 115°C), slightly higher VF (0.49 V @ 9 A, 125°C) | Requires tighter thermal management due to lower max case temperature rating | Preferred where board space allows larger heatsink footprint and higher continuous current is needed |
| ON Semiconductor MBR1045CT | Dual common-cathode configuration, 45 V VRRM, 10 A total (5 A per die), higher VF (0.55 V typical) | Offers dual-diode integration but lacks single-die surge margin and thermal symmetry | Selected when dual-output rectification is required and surge immunity is secondary to cost |
Compared with VS-90SQ040 and MBR1045CT, SD940-T provides superior thermal resistance (8.0 K/W vs. ≥10 K/W) and higher single-die surge tolerance (340 A vs. ≤250 A), making it optimal for compact, high-reliability industrial rectifiers where lead-based thermal conduction is primary cooling path.
Availability
SD940-T is available at Aetrix Electronics and suitable for industrial power supplies, motor drive input stages, solar charge controllers, and telecom rectifier modules requiring stable component supply and long-term manufacturing continuity.
Supply support for SD940-T 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.
The SD9xx series belongs to Diodes' high-current Schottky rectifier product line, engineered specifically for high-efficiency, high-surge AC/DC conversion in industrial, telecom, and renewable energy power systems.
FAQ
What is the maximum allowable case temperature for continuous operation of SD940-T?
The SD940-T is rated for 9.0 A average forward current at TC = 120°C, with absolute maximum operating temperature of +150°C. Sustained operation above 120°C requires derating per Fig. 1 in the datasheet-e.g., 6.5 A at TC = 140°C. Exceeding 150°C risks irreversible parametric shift and bond wire failure.
Can SD940-T be used in surface-mount designs?
No-SD940-T uses the DO-201AD through-hole package with axial leads designed for vertical PCB mounting and lead-based heat sinking. It lacks SMD-compatible terminations or thermal pad structures. For SMT equivalents, consider Diodes' APD1040SCH or Vishay VSKT40A.
How does the guard ring improve reliability in real-world applications?
The integrated guard ring mitigates electric field crowding at the silicon periphery, raising the effective dv/dt limit to 10,000 V/µs and suppressing premature edge avalanche during line transients. In practice, this prevents catastrophic failure during 1 kV/µs EFT bursts common in factory automation environments.
Is SD940-T suitable for use in Class II (double-insulated) power supplies?
Yes-its DO-201AD plastic case meets UL 94V-0 flammability requirements and provides reinforced insulation between anode and cathode terminals. Clearance and creepage distances comply with IEC 62368-1 for 40 V working voltage, provided PCB layout maintains ≥2.5 mm spacing per basic insulation requirements.
SD940-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- DO-201AD, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Technology:
- Schottky
- Voltage - DC Reverse (Vr) (Max):
- 40 V
- Current - Average Rectified (Io):
- 9A
- Voltage - Forward (Vf) (Max) @ If:
- 480 mV @ 9 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- -
- Current - Reverse Leakage @ Vr:
- 800 µA @ 40 V
- Capacitance @ Vr, F:
- 900pF @ 4V, 1MHz
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-201AD
- Operating Temperature - Junction:
- -65°C ~ 150°C
SD940-T FAQ
1.How can I place an order for SD940-T through Aetrix?
Please submit a Request for Quotation (RFQ) for SD940-T 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 SD940-T reliable?
The price and inventory of SD940-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SD940-T is usually 5 days.
3.What payment methods are accepted for SD940-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SD940-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SD940-T?
SD940-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SD940-T 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 SD940-T?
For technical support, including SD940-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SD940-T requirements.
6.How does Aetrix verify that SD940-T is sourced from the original manufacturer or authorized distributors?
All SD940-T 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 SD940-T meets industry standards.
7.What is the process for return or replacement of SD940-T?
All SD940-T units undergo pre-shipment inspection (PSI). If there is an issue with SD940-T, 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 SD940-T part is unused and in its original packaging.
Return procedure for SD940-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SD940-T Tags
-
1N4448X-TP
Micro Commercial Co
-
1N4148WX-TP
Micro Commercial Co
-
1N4148TR
onsemi
-
MMSD4148T1G
onsemi
-
MMBD914LT3G
onsemi
-
BAS16HT1G
onsemi
-
1N914BWT
onsemi
-
BAS21LT1G
onsemi
-
LL4148
onsemi
-
BAS16LT1G
onsemi
-
MMSD914T1G
onsemi
-
BAV21W-7-F
Diodes Incorporated
Tech Hub
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
