My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMF45A-HM3-18
- Part No.:
- SMF45A-HM3-18
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF45A-HM3-18.pdf
- Description:
- TVS DIODE 45VWM 72.7VC SMF
- Quantity:
- Payment:
- Shipping:
Inventory:6,168
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMF45A-HM3-18 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in the SMF (DO-219AB) package, designed for transient voltage suppression in high-speed data lines and power rails. It features a 45 V stand-off voltage (VRWM), 50 V minimum reverse breakdown voltage (VBR), 72.7 V maximum clamping voltage at 2.8 A peak pulse current, ±30 kV IEC 61000-4-2 ESD immunity, and 162 pF typical junction capacitance at 0 V.
For engineers reviewing the SMF45A-HM3-18 datasheet, SMF45A-HM3-18 pinout, SMF45A-HM3-18 application, or SMF45A-HM3-18 equivalent, this device is selected for robust electrostatic discharge protection in automotive infotainment interfaces, USB 2.0 signal lines, and industrial sensor I/O where low clamping voltage and sub-1 ns response time are critical.
Technical Context
This diode operates as a unidirectional TVS device with avalanche breakdown behavior, optimized for fast transient suppression on single-line or rail-to-rail configurations. Its low incremental surge resistance ensures minimal voltage overshoot during 10/1000 μs surges, while its "Low Noise" technology enables sub-nanosecond response to ESD events per IEC 61000-4-2.
The SMF45A-HM3-18 is AEC-Q101 qualified for automotive applications and rated for continuous operation from –65 °C to +175 °C. It delivers 200 W peak pulse power (10/1000 μs) and 1000 W (8/20 μs), with thermal resistance RthJA = 180 K/W on standard epoxy-glass PCBs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 45 V - Maximum continuous reverse operating voltage before leakage exceeds 0.1 µA. |
| Reverse Breakdown (VBR) | 50–55.3 V at 1 mA - Ensures reliable triggering above system nominal voltage with margin. |
| Clamping Voltage (VC) | 72.7 V at 2.8 A (10/1000 µs) - Limits downstream IC stress during surge events. |
| Junction Capacitance (CD) | 162 pF at 0 V, 1 MHz - Compatible with USB 2.0 (≤480 Mbps) and CAN FD signal integrity requirements. |
| ESD Immunity | ±30 kV contact / ±30 kV air (IEC 61000-4-2) - Meets automotive and industrial ESD robustness standards. |
| Peak Pulse Power | 200 W (10/1000 µs), 1000 W (8/20 µs) - Supports both ESD and lightning-induced surge protection tiers. |
| Operating Temperature | –65 °C to +175 °C - Validated for under-hood automotive and industrial ambient extremes. |
Pinout & Package
SMF45A-HM3-18 uses the DO-219AB (SOD-123W-compatible) low-profile surface-mount package: 3.9 mm × 1.9 mm × 1.08 mm, cathode-bar marked, MSL level 1, reflow-solderable up to 260 °C peak.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input/Line side terminal | Connected to protected signal or power line; conducts during forward surge or clamp event. |
| Cathode | Ground/reference terminal | Connected to system ground or low-impedance return path; defines unidirectional clamping polarity. |
Key Features
| Feature | Design Value |
|---|---|
| Unidirectional TVS architecture | Enables rail-to-ground protection without affecting DC bias on bidirectional lines like RS-485 or CAN. |
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD stress per JESD22-A114. |
| Low clamping ratio (VC/VBR ≈ 1.45) | Minimizes overvoltage exposure to downstream ICs compared to higher-ratio alternatives. |
| Sub-1 ns response time | "Low Noise" silicon process ensures effective suppression of ESD transients before IC input structures fail. |
| SOD-123W footprint compatibility | Enables drop-in replacement in existing layouts designed for industry-standard SOD-123W packages. |
Applications
| Automotive Infotainment Display Interface | Industrial RS-485 Communication Port |
|---|---|
Use Scenario: Protecting LVDS or FPD-Link III video data lines between head unit and display panel against ESD during assembly and field use. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed inline on each differential pair, referenced to chassis ground. Use Value: Clamps transients to ≤72.7 V while maintaining 162 pF capacitance-preserving signal integrity up to 1 Gbps without measurable jitter increase. |
Use Scenario: Safeguarding RS-485 transceiver I/O pins in factory automation controllers exposed to cable-discharge events. IC Role / Device Role / Timing Role: Rail-to-ground protection on A/B bus lines, leveraging unidirectional polarity to avoid interfering with common-mode voltage range. Use Value: Withstands ±30 kV contact ESD and limits clamping voltage below RS-485 receiver absolute max rating (±12 V common-mode + 12 V differential). |
| USB 2.0 Host Port Protection | Automotive Sensor Power Input (5 V Rail) |
Use Scenario: ESD protection on D+ and D– lines of USB 2.0 upstream ports in telematics control units. IC Role / Device Role / Timing Role: Dual-diode configuration (one per line) with cathodes tied to ground, enabling independent line-to-ground clamping. Use Value: 162 pF capacitance meets USB 2.0 eye diagram mask requirements; 72.7 V clamping prevents damage to USB PHY's 3.3 V I/O structures. |
Use Scenario: Transient suppression on 5 V supply inputs to MEMS pressure sensors mounted near engine compartments. IC Role / Device Role / Timing Role: Cathode-to-rail configuration (reverse-biased) to clamp positive surges on VCC line to ground. Use Value: 45 V VRWM allows safe operation across full automotive battery range (9–16 V), while 200 W surge rating handles load-dump induced spikes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ45A | Same VRWM (45 V), higher VC (73 V), 200 W rating, SMA package (larger footprint, 4.5 mm × 2.7 mm). | Less suitable for space-constrained USB or LVDS routing due to 2.6× larger PCB area. | Select when legacy SMA layout exists or higher thermal mass is needed for repetitive surge duty. |
| ON Semiconductor SZ1.5SMC47A | Higher VRWM (47 V), higher VC (76 V), 1500 W (8/20 µs), DO-214AB package (5.3 mm × 2.7 mm). | Designed for higher-energy surges (e.g., AC mains coupling); excessive clamping voltage for 3.3 V/5 V logic protection. | Prefer only for 12 V–24 V power rail protection where tighter clamping is not required. |
Compared with SMAJ45A and SZ1.5SMC47A, SMF45A-HM3-18 offers the smallest footprint (DO-219AB), lowest capacitance among 45 V-class unidirectional TVS diodes, and AEC-Q101 qualification-making it optimal for high-density automotive signal line protection where board space and signal fidelity are constrained.
Availability
SMF45A-HM3-18 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial communication ports, USB 2.0 interfaces, and sensor power rail protection requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SMF45A-HM3-18 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 Semiconductors is a global leader in discrete semiconductors, specializing in high-reliability diodes, MOSFETs, optoelectronics, and passive components for automotive, industrial, and computing markets.
The SMF series targets high-speed signal line protection with AEC-Q101 qualification, low capacitance, and tight clamping-designed specifically for next-generation automotive electronics and industrial IoT interfaces demanding robust ESD resilience without signal degradation.
FAQ
What is the clamping voltage of SMF45A-HM3-18 at its rated peak pulse current?
The SMF45A-HM3-18 has a maximum clamping voltage (VC) of 72.7 V at 2.8 A peak pulse current with a 10/1000 µs waveform. This value is measured under standardized surge conditions and ensures downstream ICs remain within safe operating voltage limits during transient events. The clamping performance is guaranteed across the full operating temperature range of –65 °C to +175 °C.
Is SMF45A-HM3-18 qualified for automotive applications?
Yes, SMF45A-HM3-18 is AEC-Q101 qualified for automotive applications. It undergoes rigorous stress testing-including high-temperature reverse bias, temperature cycling, and ESD robustness per JESD22-A114-to ensure reliability in under-hood and cabin environments. The qualification applies directly to the SMF45A-HM3-18 part number as shipped in the DO-219AB package with HM3-18 tape-and-reel packaging.
What does the "HM3-18" suffix indicate in SMF45A-HM3-18?
The "HM3-18" suffix denotes Vishay's packaging and environmental coding: "H" indicates AEC-Q101 qualification, "M3" specifies RoHS-compliant, lead-free terminations with matte tin plating, and "18" means 10,000 units per 13-inch reel (8 mm tape, MOQ = 50,000). This packaging format supports high-volume automated assembly in automotive and industrial manufacturing lines.
Can SMF45A-HM3-18 be used for bidirectional signal lines like RS-485?
SMF45A-HM3-18 is unidirectional and must be used in pairs (anode-to-line/cathode-to-ground for positive transients, or cathode-to-line/anode-to-ground for negative) to protect bidirectional lines. For single-device bidirectional protection, a dedicated bidirectional TVS such as SMF45CA would be required-but SMF45A-HM3-18 remains preferred where polarity is known and layout density favors discrete unidirectional placement.
What is the thermal resistance (RthJA) of SMF45A-HM3-18 on a standard PCB?
The junction-to-ambient thermal resistance (RthJA) of SMF45A-HM3-18 is 180 K/W when mounted on an epoxy-glass PCB with 3 mm × 3 mm copper pads ≥40 µm thick. This value assumes standard JEDEC test conditions (J-STD-020) and informs derating calculations for repetitive surge duty cycles. No heatsink or additional copper pour is required for single-event ESD protection.
SMF45A-HM3-18 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):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.7V
- Current - Peak Pulse (10/1000µs):
- 2.8A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- 162pF @ 1MHz
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AB (SMF)
SMF45A-HM3-18 FAQ
1.How can I place an order for SMF45A-HM3-18 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF45A-HM3-18 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 SMF45A-HM3-18 reliable?
The price and inventory of SMF45A-HM3-18 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF45A-HM3-18 is usually 5 days.
3.What payment methods are accepted for SMF45A-HM3-18?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF45A-HM3-18 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF45A-HM3-18?
SMF45A-HM3-18 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF45A-HM3-18 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 SMF45A-HM3-18?
For technical support, including SMF45A-HM3-18 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF45A-HM3-18 requirements.
6.How does Aetrix verify that SMF45A-HM3-18 is sourced from the original manufacturer or authorized distributors?
All SMF45A-HM3-18 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 SMF45A-HM3-18 meets industry standards.
7.What is the process for return or replacement of SMF45A-HM3-18?
All SMF45A-HM3-18 units undergo pre-shipment inspection (PSI). If there is an issue with SMF45A-HM3-18, 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 SMF45A-HM3-18 part is unused and in its original packaging.
Return procedure for SMF45A-HM3-18:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF45A-HM3-18 Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
