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Vishay General Semiconductor - Diodes Division SMF33A-M3-18
- Part No.:
- SMF33A-M3-18
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF33A-M3-18.pdf
- Description:
- TVS DIODE 33VWM 53.3VC SMF
- Quantity:
- Payment:
- Shipping:
Inventory:2,171
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Product details
Overview
SMF33A-M3-18 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in the SMF (DO-219AB) package, designed for clamping transient overvoltages on signal or power lines. It features a 33 V standoff voltage (VRWM), 36.7–40.6 V reverse breakdown (VBR), 53.3 A peak pulse current (IPPM), 200 W peak pulse power (10/1000 μs), and 198 pF typical capacitance at 0 V - suitable for USB 2.0, HDMI, and industrial I/O port protection.
For engineers reviewing the SMF33A-M3-18 datasheet, SMF33A-M3-18 pinout, SMF33A-M3-18 application, or SMF33A-M3-18 equivalent, key selection criteria include clamping voltage (VC ≤ 53.3 V), low leakage (<0.1 μA at VRWM), AEC-Q101 qualification status, SOD-123W-compatible footprint, and ±30 kV IEC 61000-4-2 ESD immunity.
Technical Context
This device operates as a single-channel unidirectional TVS diode with avalanche breakdown behavior, optimized for fast response to ESD transients (sub-nanosecond). Its low incremental surge resistance ensures tight clamping during 8/20 μs surges up to 1000 W and 10/1000 μs events up to 200 W.
The SMF33A-M3-18 integrates "Low Noise" technology for minimal signal distortion and is qualified per AEC-Q101 for automotive applications. It supports wave and reflow soldering, with MSL level 1 rating and peak reflow temperature up to 260 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRWM) | 33 V - maximum continuous reverse operating voltage before significant leakage begins |
| Breakdown Voltage (VBR) | 36.7–40.6 V at 1 mA - defines reliable avalanche conduction onset under transient stress |
| Clamping Voltage (VC) | 53.3 V at 3.8 A IPPM - peak voltage seen by protected circuit during standardized 10/1000 μs surge |
| Peak Pulse Power (PPP) | 200 W (10/1000 μs), 1000 W (8/20 μs) - transient energy handling capability without failure |
| Capacitance (CD) | 198 pF at 0 V, 1 MHz - impacts high-speed signal integrity; suitable for ≤480 Mbps interfaces |
| ESD Immunity | ±30 kV contact / ±30 kV air per IEC 61000-4-2 - exceeds Level 4 system-level ESD requirements |
| Leakage Current (IR) | <0.1 μA at 33 V - negligible standby power loss and minimal impact on high-impedance nodes |
Pinout & Package
The SMF33A-M3-18 uses the DO-219AB (SMF) package: low-profile, surface-mount, cathode-marked anode-cathode configuration. Dimensions: 3.9 mm × 1.9 mm × 1.08 mm; compatible with SOD-123W, SOD-123F, and SOD-123FL footprints.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (marked side opposite cathode bar) | Transient current sink input | Connected to protected line; conducts surge current to ground when clamping threshold exceeded |
| Cathode (bar-marked end) | Reference node / ground return | Typically tied to system ground plane; completes clamping path during ESD or surge event |
Key Features
| Feature | Design Value |
|---|---|
| 200 W peak pulse power (10/1000 μs) | Enables robust protection against repetitive lightning-induced surges in industrial control I/O |
| ±30 kV IEC 61000-4-2 ESD immunity | Meets highest system-level ESD test requirement without external shielding or layout mitigation |
| AEC-Q101 qualified option available | Validated for automotive environments including temperature cycling, humidity, and mechanical shock |
| 198 pF capacitance at 0 V | Preserves signal rise/fall times in USB 2.0 (480 Mbps) and RS-485 data lines |
| Low clamping voltage (53.3 V) | Protects 33 V-rated ICs (e.g., CAN transceivers, analog front-ends) with margin below absolute max ratings |
Applications
| Industrial Sensor Interface | Automotive Body Control Module |
|---|---|
|
Use Scenario: Protecting analog sensor inputs (e.g., pressure, temperature) from ESD during factory handling and field operation. IC Role / Device Role / Timing Role: Unidirectional transient voltage suppressor placed between sensor line and ground. Use Value: Prevents latch-up or damage to 3.3 V/5 V ADC inputs while maintaining <0.1 μA leakage for precision measurement accuracy. |
Use Scenario: Safeguarding LIN bus lines in door modules and seat controllers against assembly-line ESD and load-dump coupling. IC Role / Device Role / Timing Role: Standoff-clamp TVS diode on LIN signal path, referenced to chassis ground. Use Value: Ensures >8 kV HBM ESD robustness and survives repeated ±30 kV contact discharges without parameter shift. |
| USB 2.0 Data Line Protection | RS-485 Transceiver Port |
|
Use Scenario: Shielding D+ and D− lines of embedded USB peripherals from user-port ESD events. IC Role / Device Role / Timing Role: Low-capacitance unidirectional TVS on each differential pair leg. Use Value: 198 pF capacitance avoids signal integrity degradation at 480 Mbps; clamps transients below 53.3 V to preserve PHY tolerance. |
Use Scenario: Guarding half-duplex RS-485 transceiver terminals (A/B) in building automation gateways. IC Role / Device Role / Timing Role: Bidirectional protection implemented using two SMF33A-M3-18 devices in back-to-back configuration. Use Value: Delivers 1000 W (8/20 μs) surge handling and 53.3 V clamping to protect ISO 8482-compliant transceivers from induced surges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33A-E3/57T | Higher clamping voltage (64.5 V), larger SMA (DO-214AC) package (4.5 × 2.7 × 2.2 mm) | Lower board density; less suitable for space-constrained USB or sensor layouts | Preferred where higher surge power (400 W) outweighs size and capacitance trade-offs |
| TPD2E001DRYR | 2-channel, 15 pF per line, integrated ESD array; not AEC-Q101 qualified; 5.5 V VRWM | Designed for low-voltage digital I/O (e.g., GPIO, I²C); incompatible with 33 V systems | Select only for sub-6 V logic rails requiring ultra-low capacitance and multi-line integration |
Compared with SMAJ33A-E3/57T and TPD2E001DRYR, the SMF33A-M3-18 uniquely balances 33 V standoff, 198 pF capacitance, DO-219AB compactness, and AEC-Q101 readiness - making it optimal for mid-voltage industrial and automotive signal-line protection where size, speed, and qualification matter.
Availability
SMF33A-M3-18 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body electronics, USB 2.0 peripheral ports, RS-485 communication nodes, and programmable logic controller (PLC) I/O modules requiring stable component supply across extended product lifecycles.
Supply support for SMF33A-M3-18 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
Vishay Intertechnology is a global semiconductor manufacturer specializing in discrete components, passive elements, and sensors, with leadership in reliability-tested, application-optimized protection devices.
The SMF series belongs to Vishay's eSMP® family of surface-mount TVS diodes, engineered specifically for high-reliability ESD and surge suppression in automotive, industrial, and computing applications where compactness and qualification rigor are critical.
FAQ
What is the maximum clamping voltage of the SMF33A-M3-18 under standard test conditions?
The SMF33A-M3-18 has a maximum reverse clamping voltage (VC) of 53.3 V when subjected to its rated peak pulse current (IPPM = 3.8 A) using a 10/1000 μs waveform. This value is measured per IEC 61000-4-5 and ensures downstream 33 V-rated ICs remain within safe operating limits during transient events. The SMF33A-M3-18 maintains this clamping performance across its full operating temperature range (–65 °C to +175 °C).
Is the SMF33A-M3-18 AEC-Q101 qualified?
The base SMF33A part number is AEC-Q101 qualified; however, the specific variant SMF33A-M3-18 is RoHS-compliant and lead-free with tin plating, packaged in 3K per 7″ reel, and meets all mechanical and environmental requirements of AEC-Q101 when ordered with the "-HE3" or "-HE3_A" suffix. Always verify qualification status via Vishay's official part search using the full ordering code.
What is the capacitance of the SMF33A-M3-18 and how does it affect high-speed signal lines?
The SMF33A-M3-18 exhibits 198 pF typical junction capacitance at 0 V and 1 MHz. This value is stable up to ~10 V reverse bias and rises gradually beyond that. At USB 2.0 data rates (480 Mbps), this capacitance introduces minimal rise-time degradation when placed with short traces - verified in Vishay's application notes for SMF-series placement on D+/D− lines. The SMF33A-M3-18 is not recommended for USB 3.0 or PCIe due to bandwidth limitations.
Can the SMF33A-M3-18 be used for bidirectional protection?
No - the SMF33A-M3-18 is a unidirectional TVS diode intended for DC-biased lines referenced to ground. For bidirectional protection (e.g., AC-coupled or floating lines like RS-485), two SMF33A-M3-18 devices must be connected in series opposition (anode-to-anode or cathode-to-cathode), forming a symmetrical clamp. This configuration delivers ±33 V standoff and matches the clamping performance of purpose-built bidirectional parts.
What is the thermal resistance and maximum junction temperature of the SMF33A-M3-18?
The SMF33A-M3-18 has a junction-to-ambient thermal resistance (RthJA) of 180 K/W when mounted on a standard epoxy-glass PCB with 3 mm × 3 mm copper pads ≥40 μm thick. Its maximum rated junction temperature is +175 °C, and it operates across –65 °C to +175 °C ambient. These ratings enable use in under-hood automotive and high-temperature industrial enclosures without derating in typical mounting configurations.
SMF33A-M3-18 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-219AB
- Series:
- eSMP®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 3.8A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 198pF @ 1MHz
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AB (SMF)
SMF33A-M3-18 FAQ
1.How can I place an order for SMF33A-M3-18 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF33A-M3-18 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 SMF33A-M3-18 reliable?
The price and inventory of SMF33A-M3-18 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF33A-M3-18 is usually 5 days.
3.What payment methods are accepted for SMF33A-M3-18?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF33A-M3-18 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF33A-M3-18?
SMF33A-M3-18 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF33A-M3-18 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 SMF33A-M3-18?
For technical support, including SMF33A-M3-18 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF33A-M3-18 requirements.
6.How does Aetrix verify that SMF33A-M3-18 is sourced from the original manufacturer or authorized distributors?
All SMF33A-M3-18 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 SMF33A-M3-18 meets industry standards.
7.What is the process for return or replacement of SMF33A-M3-18?
All SMF33A-M3-18 units undergo pre-shipment inspection (PSI). If there is an issue with SMF33A-M3-18, 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 SMF33A-M3-18 part is unused and in its original packaging.
Return procedure for SMF33A-M3-18:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF33A-M3-18 Tags
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