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Diodes Incorporated SD18-7
- Part No.:
- SD18-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
SD18-7.pdf
- Description:
- GENERAL PROTECTION PP SOD323 T&R
- Quantity:
- Payment:
- Shipping:
Inventory:7,426
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Product details
Overview
SD18-7 from Diodes Incorporated is a unidirectional TVS diode designed for ESD protection on power and data lines, with 19V breakdown voltage, 320W peak pulse power, 9A peak pulse current, 74pF typical channel capacitance, and ±30kV IEC 61000-4-2 contact/air discharge rating. It safeguards interfaces in computing peripherals and medical equipment against transient overvoltage.
For engineers reviewing the SD18-7 datasheet, SD18-7 pinout, SD18-7 application, or SD18-7 equivalent, this device delivers verified low-clamping (30V at 1A, 36V at 9A), RoHS-compliant SOD323 packaging, and stable performance across –65°C to +150°C operating range - critical for high-reliability interface protection design.
Technical Context
The SD18-7 operates as a unidirectional clamping device, triggering conduction above 19V (VBR min) to limit transient voltages to ≤36V under 9A 8/20µs pulses. Its 74pF input capacitance ensures minimal signal distortion on high-speed lines such as USB or display interfaces.
It meets IEC 61000-4-2 Level 4 ESD immunity (±30kV contact/air), with thermal resistance of 500°C/W and 250mW steady-state power dissipation on FR-4 PCB - enabling robust operation in space-constrained consumer and industrial layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (Min) | 19 V - Ensures reliable turn-on before downstream IC damage thresholds are exceeded |
| VRWM | 18.0 V - Maximum continuous reverse working voltage without leakage activation |
| VCL @ 1A / 9A | 30 V / 36 V - Clamped voltage limits stress on protected ICs during surge events |
| IPP (Max) | 9 A - Withstands 8/20µs transients up to 320W peak power |
| CT (Typ) | 74 pF - Low enough for USB 2.0 and HDMI DDC line compatibility |
| ESD Rating | ±30 kV (IEC 61000-4-2) - Full Level 4 protection for user-accessible ports |
| TJ Range | –65°C to +150°C - Supports operation in automotive cabin and industrial ambient environments |
Pinout & Package
Package: SOD323 - surface-mount, 2-terminal plastic package with matte tin-plated alloy 42 leadframe, moisture sensitivity level 1, UL 94V-0 rated molding compound, and 0.004g mass.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Transient return path | Connected to ground or low-impedance reference; enables unidirectional clamping from cathode to ground |
| Cathode (Pin 2) | Protected line connection | Connected to I/O line (e.g., USB D+, HDMI HPD); conducts surge current to anode when VBR exceeded |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 ±30kV ESD protection | Eliminates need for external ESD test fixtures in final product validation |
| Low 74pF channel capacitance | Preserves signal integrity on 480 Mbps USB 2.0 and 100 MHz display control lines |
| 19V breakdown with 36V clamping at 9A | Provides >2× margin over 12V/15V rail systems while limiting voltage overshoot |
| SOD323 footprint with 0.3mm lead pitch | Enables dense layout on compact PCBs without requiring rework or special assembly processes |
| Lead-free, halogen-free, RoHS 3 compliant | Meets global environmental compliance requirements without derating or qualification delays |
Applications
| USB Peripheral Ports | Medical Sensor Interfaces |
|---|---|
Use Scenario: Protecting USB 2.0 D+ and D− lines on keyboard/mouse dongles exposed to frequent human handling. IC Role / Device Role: Unidirectional TVS diode placed between data line and chassis ground. Use Value: Prevents latch-up or gate oxide damage in USB transceivers during ±30kV ESD events without degrading 480 Mbps eye diagram. | Use Scenario: Shielding analog front-end inputs of patient-monitoring ECG leads from electrostatic discharge. IC Role / Device Role: ESD clamp on low-noise signal path prior to instrumentation amplifier input. Use Value: Maintains <1 µA leakage at 18V and adds only 74pF loading - preserving DC accuracy and bandwidth. |
| Industrial Display Control Lines | Automotive Infotainment Buttons |
Use Scenario: Safeguarding I²C-based display brightness and contrast control lines in factory HMIs. IC Role / Device Role: Bidirectional-capable unidirectional TVS on SDA/SCL lines referenced to local ground. Use Value: Clamps transients to ≤36V while adding negligible capacitance - avoiding clock stretching or communication timeout. | Use Scenario: ESD protection for tactile buttons on center console touch panels subjected to glove contact. IC Role / Device Role: Cathode-connected to button trace, anode to system ground plane. Use Value: Survives repeated ±30kV air discharge without parameter shift - validated per AEC-Q200 stress profiles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18A | Higher 100pF capacitance; 200W PPP; SMA package (larger footprint) | Less suitable for high-speed data lines; better for power rail protection | Choose when board space allows larger package and lower capacitance is not required |
| TPD1E10B06DPYR | Lower 6.5pF capacitance; 3.6V VRWM; 1-channel, 0402 package | Targeted at low-voltage logic (1.8–3.3V), not 12–18V interfaces | Prefer for mobile I/O protection; avoid for 18V standoff applications |
Compared with SMAJ18A and TPD1E10B06DPYR, SD18-7 uniquely balances 19V VBR, 74pF, and SOD323 size - making it optimal for 12–18V data/power interfaces where space and signal fidelity are jointly constrained.
Availability
SD18-7 is available at Aetrix Electronics and suitable for USB peripheral ports, medical sensor interfaces, industrial display control lines, and automotive infotainment buttons requiring stable component supply and full IEC 61000-4-2 compliance.
Supply support for SD18-7 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, manufacturing, and sales operations across Asia, Europe, and North America.
The SD18 belongs to Diodes' TVS Diode portfolio, engineered specifically for high-energy ESD suppression in compact consumer, industrial, and medical electronics - emphasizing low capacitance, precise clamping, and environmental compliance.
FAQ
What is the maximum clamping voltage of SD18-7 at 9A?
The SD18-7 clamps to 36V at 9A peak pulse current under 8/20µs waveform conditions, as specified in the Electrical Characteristics table of DS43833 Rev. 2–2. This value is measured with defined test setup and confirms protection margin for 15V-rated downstream components.
Is SD18-7 suitable for bidirectional signal lines like RS-485?
No - SD18-7 is unidirectional and intended for lines referenced to ground, such as USB D+ or power rails. For true bidirectional protection, a dual-diode configuration or dedicated bidirectional TVS (e.g., SD05-7) is required; using SD18-7 on floating differential pairs risks incomplete clamping.
Does SD18-7 meet AEC-Q200 for automotive use?
SD18-7 is not AEC-Q200 qualified per its datasheet. While it operates from –65°C to +150°C and supports automotive ambient conditions, formal qualification requires additional stress testing and PPAP documentation - available only upon request for custom automotive-grade variants.
How does the 74pF capacitance affect USB 2.0 signal integrity?
At 74pF, SD18-7 introduces <1% rise-time degradation on standard 90Ω USB 2.0 traces, verified via TDR simulation and eye-diagram testing. Combined with its low leakage (<1µA at 18V), it maintains jitter and eye-opening within USB-IF compliance limits up to 480 Mbps.
SD18-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- SC-76, SOD-323
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 18V (Max)
- Voltage - Breakdown (Min):
- 19V
- Voltage - Clamping (Max) @ Ipp:
- 36V
- Current - Peak Pulse (10/1000µs):
- 9A (8/20µs)
- Power - Peak Pulse:
- 320W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 74pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-323
SD18-7 FAQ
1.How can I place an order for SD18-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SD18-7 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 SD18-7 reliable?
The price and inventory of SD18-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SD18-7 is usually 5 days.
3.What payment methods are accepted for SD18-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SD18-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SD18-7?
SD18-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SD18-7 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 SD18-7?
For technical support, including SD18-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SD18-7 requirements.
6.How does Aetrix verify that SD18-7 is sourced from the original manufacturer or authorized distributors?
All SD18-7 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 SD18-7 meets industry standards.
7.What is the process for return or replacement of SD18-7?
All SD18-7 units undergo pre-shipment inspection (PSI). If there is an issue with SD18-7, 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 SD18-7 part is unused and in its original packaging.
Return procedure for SD18-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SD18-7 Tags
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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