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Vishay General Semiconductor - Diodes Division SMCJ20A-M3/9AT
- Part No.:
- SMCJ20A-M3/9AT
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ20A-M3/9AT.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:5,886
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Product details
Overview
SMCJ20A-M3/9AT from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMC (DO-214AB) package, designed for robust overvoltage protection of DC power rails and signal lines. It features a 20 V standoff voltage (VWM), 22.2–24.5 V breakdown voltage (VBR at 1 mA), 32.4 V clamping voltage (VC) at 46.3 A peak pulse current, and 1500 W peak pulse power rating with 10/1000 µs waveform.
For engineers reviewing the SMCJ20A-M3/9AT datasheet, SMCJ20A-M3/9AT pinout, SMCJ20A-M3/9AT application, or SMCJ20A-M3/9AT equivalent, this device is selected for high-energy surge immunity in automotive power supplies, industrial sensor interfaces, and DC-DC converter input protection where fast response (<1 ns), low clamping ratio, and AEC-Q101-compliant variants are critical.
Technical Context
The SMCJ20A-M3/9AT operates as a silicon avalanche diode that enters controlled breakdown above its reverse standoff voltage to shunt transient energy away from protected circuitry. Its glass-passivated junction ensures stable VBR tolerance (±5%) and low incremental surge resistance, enabling consistent clamping performance under repetitive surges.
Designed for unidirectional operation, it exhibits polarity-sensitive mounting (cathode marked by band), forward voltage drop of 3.5 V at 100 A, and thermal resistance of 75 °C/W (junction-to-ambient) on standard 8 mm × 8 mm copper pads - key parameters governing layout-dependent power derating above 25 °C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum continuous reverse operating voltage before leakage exceeds 1 µA; defines upper limit of normal DC rail voltage it can protect without conduction. |
| VBR (min/max) | 22.2 V / 24.5 V at 1 mA - Verified breakdown threshold range; ensures reliable triggering within ±5% tolerance across production lots. |
| VC @ IPPM | 32.4 V at 46.3 A - Clamped voltage during 1500 W transient; determines maximum stress imposed on downstream ICs during surge events. |
| PPPM | 1500 W - Peak pulse power handling with 10/1000 µs waveform; quantifies single-event surge energy absorption capability. |
| TJ max. | +150 °C - Maximum junction temperature; sets thermal design margin for sustained power dissipation and surge repetition rate. |
| Package | SMC (DO-214AB) - Standardized surface-mount outline with 7.75 mm × 6.22 mm footprint and 2.62 mm height; compatible with automated pick-and-place and reflow soldering. |
Pinout & Package
SMCJ20A-M3/9AT uses the SMC (DO-214AB) package: a two-terminal, surface-mount plastic case with cathode identified by a visible band. Terminals are matte tin-plated leads, solderable per J-STD-002 and JESD 22-B102, rated MSL Level 1 (peak reflow 260 °C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection point | Connected to ground or return path; completes current loop during transient clamping. |
| Cathode | High-side connection point | Connected to protected line (e.g., 20 V rail); band marking confirms polarity for correct unidirectional installation. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low clamping ratio | VC/VBR ≈ 1.36 - Minimizes voltage overshoot during transients, reducing risk of latch-up or damage to 24 V-rated ICs. |
| Fast response time | < 1 ns - Enables suppression of ESD and lightning-induced spikes before sensitive components react. |
| Halogen-free & RoHS-compliant | M3 suffix - Meets environmental compliance requirements for industrial and automotive end equipment without compromising surge performance. |
| High surge current capability | IPPM = 46.3 A - Supports IEC 61000-4-5 Level 4 (4 kV/2 Ω) surge testing on 20 V supply lines. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface |
|---|---|
Use Scenario: Protecting 12–24 V battery-fed ECUs against load dump (ISO 7637-2 Pulse 5a) and alternator transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power input and ground to clamp surges up to 1500 W without degradation. Use Value: Maintains system uptime by preventing microcontroller reset or CAN transceiver damage during vehicle ignition cycles. | Use Scenario: Shielding 4–20 mA current-loop sensors in factory automation from induced surges on long cable runs. IC Role / Device Role / Timing Role: Standoff-rated TVS on analog input side, absorbing fast transients while preserving signal integrity below 20 V. Use Value: Eliminates false readings and field-replacement costs by ensuring sensor output remains stable under 1 kV EFT bursts. |
| DC-DC Converter Input Stage | Telecom Line Card Surge Protection |
Use Scenario: Safeguarding buck converter inputs in PoE-powered devices exposed to Ethernet-coupled surges. IC Role / Device Role / Timing Role: Primary clamping device upstream of input capacitor, limiting voltage seen by MOSFET gate drivers and controllers. Use Value: Prevents catastrophic failure of switching FETs during 10/1000 µs surges, extending mean time between failures (MTBF). | Use Scenario: Front-end protection for AC/DC power supplies in telecom base stations subjected to lightning-induced surges. IC Role / Device Role / Timing Role: High-power TVS on bulk input rail, coordinated with MOVs to handle multi-kW transients per IEC 61000-4-5. Use Value: Reduces need for oversized input capacitors and enables compact, cost-effective front-end designs meeting GR-1089-CORE. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SAC20A-TB-E3/57T | Same VWM (20 V), lower PPPM (600 W), smaller SMA package | Limited to lower-energy transients (e.g., ESD only); unsuitable for ISO 7637-2 load dump | Select when board space is constrained and surge threat level is ≤ IEC 61000-4-2 Level 4. |
| 1.5KE20A | Through-hole DO-201 package, identical electrical specs but higher RθJA (100 °C/W) | Requires manual assembly or wave soldering; less suitable for high-density automated PCBs | Choose for legacy through-hole designs or prototyping where reflow compatibility is not required. |
Compared with SAC20A-TB-E3/57T and 1.5KE20A, the SMCJ20A-M3/9AT delivers optimal balance of high surge capacity (1500 W), surface-mount compatibility, and thermal performance (RθJA = 75 °C/W) for volume-manufactured automotive and industrial systems requiring AEC-Q101 alignment.
Availability
SMCJ20A-M3/9AT is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor interface hardening, and DC-DC converter input stage surge mitigation requiring stable component supply across extended production lifecycles.
Supply support for SMCJ20A-M3/9AT 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 General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, TVS devices, and optoelectronics with emphasis on reliability, precision, and application-specific optimization.
The SMCJ series is engineered for high-energy transient suppression in harsh environments - targeting automotive, industrial, and telecom applications where robustness against ISO 7637-2, IEC 61000-4-5, and EFT threats is mandatory.
FAQ
What is the maximum clamping voltage of the SMCJ20A-M3/9AT under a 10/1000 µs surge?
The SMCJ20A-M3/9AT clamps to a maximum of 32.4 V when subjected to its rated 46.3 A peak pulse current (IPPM) with a 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and confirmed in Vishay's datasheet Document Number 88394, page 2. The clamping voltage directly determines the peak stress imposed on protected circuitry during surge events, making it critical for validating downstream IC voltage tolerances.
Is the SMCJ20A-M3/9AT suitable for automotive applications requiring AEC-Q101 qualification?
No - the SMCJ20A-M3/9AT carries the M3 suffix (halogen-free, RoHS-compliant commercial grade) but is not AEC-Q101 qualified. For automotive use, select the HM3-suffixed variant (e.g., SMCJ20AHM3_A/I), which is explicitly qualified per AEC-Q101 and documented in the same datasheet under "Ordering Information" on page 3. The SMCJ20A-M3/9AT remains appropriate for industrial and telecom applications where AEC-Q101 is not mandated.
How does the SMCJ20A-M3/9AT differ from bidirectional SMCJ20CA variants?
The SMCJ20A-M3/9AT is unidirectional, with polarity marked by a cathode band and forward voltage (VF) of 3.5 V at 100 A; it protects only against negative transients relative to ground. In contrast, SMCJ20CA is bidirectional, has no polarity marking, and clamps symmetrically in both directions - essential for AC signal lines or differential buses. Their VWM, VBR, and VC values differ accordingly, and they are not interchangeable without circuit redesign.
What is the thermal resistance and recommended pad layout for SMCJ20A-M3/9AT?
The SMCJ20A-M3/9AT has a typical junction-to-ambient thermal resistance (RθJA) of 75 °C/W when mounted on 0.31" × 0.31" (8.0 mm × 8.0 mm) copper pads per terminal, as specified in the datasheet. Deviation from this pad size increases thermal resistance, reducing safe surge repetition rate and steady-state power handling. Layout must maintain minimum 0.126" (3.20 mm) clearance from adjacent components to avoid thermal coupling.
Can the SMCJ20A-M3/9AT be used in parallel to increase surge current handling?
No - paralleling SMCJ20A-M3/9AT devices is not recommended due to parameter mismatch (VBR tolerance ±5%) causing uneven current sharing and potential thermal runaway. For higher surge ratings, select a single higher-power device (e.g., SMCJ33A) or implement staged protection with upstream current-limiting resistors and downstream TVS arrays. Vishay does not characterize or guarantee parallel operation of the SMCJ20A-M3/9AT.
SMCJ20A-M3/9AT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 46.3A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMC)
SMCJ20A-M3/9AT FAQ
1.How can I place an order for SMCJ20A-M3/9AT through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ20A-M3/9AT 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 SMCJ20A-M3/9AT reliable?
The price and inventory of SMCJ20A-M3/9AT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ20A-M3/9AT is usually 5 days.
3.What payment methods are accepted for SMCJ20A-M3/9AT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ20A-M3/9AT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ20A-M3/9AT?
SMCJ20A-M3/9AT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ20A-M3/9AT 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 SMCJ20A-M3/9AT?
For technical support, including SMCJ20A-M3/9AT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ20A-M3/9AT requirements.
6.How does Aetrix verify that SMCJ20A-M3/9AT is sourced from the original manufacturer or authorized distributors?
All SMCJ20A-M3/9AT 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 SMCJ20A-M3/9AT meets industry standards.
7.What is the process for return or replacement of SMCJ20A-M3/9AT?
All SMCJ20A-M3/9AT units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ20A-M3/9AT, 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 SMCJ20A-M3/9AT part is unused and in its original packaging.
Return procedure for SMCJ20A-M3/9AT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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