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Taiwan Semiconductor Corporation SMDJ20A
- Part No.:
- SMDJ20A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMDJ20A.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:7,267
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Product details
Overview
SMDJ20A from Taiwan Semiconductor is a unidirectional 3000W surface-mount transient voltage suppressor (TVS) diode with a 20V working stand-off voltage, 22.2–24.5V breakdown voltage at 1mA test current, and 32.4V maximum clamping voltage at 92.6A peak pulse current. It is designed for robust ESD and surge protection in DC power rails and signal lines of industrial control systems, automotive electronics, and telecom infrastructure.
For engineers reviewing the SMDJ20A datasheet, SMDJ20A pinout, SMDJ20A application, or SMDJ20A equivalent, key selection criteria include its DO-214AB (SMC) package compatibility, 175°C junction temperature rating, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, sub-1ps response time, and verified clamping performance under 10/1000μs transients.
Technical Context
The SMDJ20A operates as a unidirectional avalanche diode, activated when reverse voltage exceeds its 22.2–24.5V breakdown threshold. It clamps transient energy to ≤32.4V at 92.6A (10/1000μs waveform), limiting stress on downstream ICs such as microcontrollers, CAN transceivers, and power management units.
Its glass-passivated junction ensures stable leakage (<1μA at 20V), while the DO-214AB package provides low thermal resistance (RθJA = 75°C/W, RθJL = 15°C/W) and supports automated placement per J-STD-020 Level 1 moisture sensitivity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum continuous reverse operating voltage before conduction begins |
| VBR @ IT=1mA | 22.2–24.5 V - Verified breakdown range ensuring reliable turn-on margin above VWM |
| VC @ IPPM=92.6A | 32.4 V - Clamped voltage during 10/1000μs surge, defining protected circuit's max overvoltage |
| PPK | 3000 W - Peak pulse power handling capability per single non-repetitive event |
| IPPM | 92.6 A - Maximum peak impulse current supported without failure |
| TJ max | 175 °C - Maximum junction temperature enabling operation in high-ambient industrial environments |
| RθJL | 15 °C/W - Low junction-to-lead thermal resistance supporting efficient heat transfer to PCB copper |
Pinout & Package
Package: DO-214AB (SMC), surface-mount, unidirectional configuration with cathode band marking. Matte tin-plated leads, RoHS and halogen-free compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Reverse surge return path | Connected to system ground or low-impedance return plane during transient events |
| Cathode | Reverse voltage sensing / Clamping node | Connected to protected line (e.g., 24V rail, RS-485 bus); conducts when VREV > VBR |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity |
| ISO 7637-2 compliance | Validated for automotive load-dump and inductive-switching transients (Pulse 1/2a/2b/3a/3b) |
| Sub-1ps response time | Enables suppression of fast ESD events before sensitive logic or analog circuits are damaged |
| DO-214AB mechanical robustness | UL 94V-0 molding compound and JESD201 Class 2 whisker resistance support high-reliability industrial assembly |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: Protecting 24V digital input channels in programmable logic controllers against field-wiring induced surges and contact bounce. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input terminal and ground to clamp transients before reaching optocoupler or MCU GPIO. Use Value: Limits voltage to ≤32.4V during 92.6A surges, preserving signal integrity and preventing latch-up in downstream isolation stages. | Use Scenario: Safeguarding LIN bus lines and sensor supply rails in body control modules exposed to battery disconnect/load dump events. IC Role / Device Role / Timing Role: Primary clamping device on 12V/24V supply inputs, coordinated with upstream fuses and downstream LDOs. Use Value: Meets ISO 7637-2 Pulse 2b (load dump) requirements with 3000W peak power absorption and <1ps reaction to fast-edge spikes. |
| Telecom Power Supply Input | RS-485 Transceiver Interface |
Use Scenario: Secondary overvoltage protection on AC/DC adapter outputs feeding telecom base station backplanes. IC Role / Device Role / Timing Role: Final-stage TVS on +48V DC distribution rail, positioned after bulk filtering and before point-of-load converters. Use Value: Clamps lightning-induced surges to 32.4V while maintaining <1μA leakage at nominal 48V–20V derating margin. | Use Scenario: Bidirectional protection on differential RS-485 data lines in factory automation gateways. IC Role / Device Role / Timing Role: Paired unidirectional SMDJ20A devices (anode-to-anode) forming a bipolar clamp across A/B lines. Use Value: Achieves symmetrical ±32.4V clamping with matched VBR (22.2–24.5V) and low capacitance, preserving 10 Mbps signal integrity. |
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 (Littelfuse) | Same DO-214AB package, identical 20V VWM, but lower PPK = 2000W and higher VC = 34.0V at 70A | Less margin for high-energy 10/1000μs transients; suitable only where peak current <70A is expected | Select SMDJ20A when full 3000W/92.6A capability is required per IEC 61000-4-5 Level 4 testing. |
| 1.5SMC20A (ON Semiconductor) | Identical electrical specs (VWM=20V, VBR=22.2–24.5V, VC=32.4V), same DO-214AB package, but rated for 1500W PPK | Not suitable for 3000W surge events; requires parallel placement or derating for equivalent energy handling | Choose SMDJ20A for single-device 3000W compliance; use 1.5SMC20A only in cost-sensitive, lower-energy designs. |
Compared with SAC20A and 1.5SMC20A, the SMDJ20A delivers verified 3000W peak power handling in a standard DO-214AB footprint-enabling direct replacement in high-surge industrial and automotive applications without layout changes or parallel device stacking.
Availability
SMDJ20A is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive BCM power rail hardening, and telecom 48V supply input surge suppression requiring stable component supply and full ISO 7637-2 compliance.
Supply support for SMDJ20A 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for industrial, automotive, and consumer markets.
The SMDJ series is engineered specifically for high-energy transient suppression in harsh electromagnetic environments, with emphasis on automotive-grade reliability, automated assembly compatibility, and standardized DO-214AB packaging.
FAQ
What is the maximum clamping voltage of the SMDJ20A under standard 10/1000μs surge conditions?
The SMDJ20A has a maximum clamping voltage (VC) of 32.4 V when subjected to a 92.6 A peak pulse current with a 10/1000μs waveform. This value is measured per JEDEC standards and defines the upper voltage limit imposed on protected circuitry during worst-case transient events. The SMDJ20A maintains this clamping performance consistently across its specified operating temperature range of –55°C to +175°C.
Is the SMDJ20A suitable for bidirectional transient protection?
No-the SMDJ20A is a unidirectional TVS diode intended for DC line protection where polarity is fixed. For bidirectional applications such as AC lines or differential buses like RS-485, the SMDJ20CA variant must be used. The SMDJ20A features a cathode band marking and conducts only in reverse bias; using it in bidirectional configurations without proper pairing risks failure during positive half-cycle surges.
What is the leakage current specification for the SMDJ20A at its rated working voltage?
The SMDJ20A exhibits a maximum reverse leakage current (IR) of 1 μA when biased at its full working stand-off voltage of 20 V and tested at 25°C. This low leakage ensures minimal power loss and no interference with upstream voltage regulation or sensing circuits. Leakage remains below 5 μA up to 80% of VWM, supporting reliable operation in precision analog and low-power IoT node designs.
Does the SMDJ20A meet automotive EMC standards beyond ISO 7637-2?
Yes-the SMDJ20A is explicitly validated to meet ISO 7637-2 Pulse 1 (inductive switch-off), Pulse 2a/2b (battery connection/disconnection), and Pulse 3a/3b (capacitive coupling), covering core conducted transient immunity requirements for automotive ECUs. While not certified to ISO 16750 or CISPR 25 itself, its clamping behavior and thermal robustness make it a common choice in front-end protection networks that achieve full system-level compliance.
What is the thermal resistance from junction to ambient for the SMDJ20A in standard PCB mounting?
The SMDJ20A has a typical junction-to-ambient thermal resistance (RθJA) of 75°C/W when mounted on a standard FR-4 PCB with minimum recommended copper pad area per the DO-214AB footprint. This value assumes no additional thermal vias or heatsinking. For high-reliability applications operating near 175°C junction limit, designers should verify board layout using the provided thermal derating curve (Fig.2) and consider adding thermal relief pads or copper pours to reduce effective RθJA.
SMDJ20A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AB, SMC
- Series:
- SMDJ
- 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):
- 92.6A
- Power - Peak Pulse:
- 3000W (3kW)
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMC)
SMDJ20A FAQ
1.How can I place an order for SMDJ20A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMDJ20A 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 SMDJ20A reliable?
The price and inventory of SMDJ20A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMDJ20A is usually 5 days.
3.What payment methods are accepted for SMDJ20A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMDJ20A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMDJ20A?
SMDJ20A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMDJ20A 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 SMDJ20A?
For technical support, including SMDJ20A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMDJ20A requirements.
6.How does Aetrix verify that SMDJ20A is sourced from the original manufacturer or authorized distributors?
All SMDJ20A 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 SMDJ20A meets industry standards.
7.What is the process for return or replacement of SMDJ20A?
All SMDJ20A units undergo pre-shipment inspection (PSI). If there is an issue with SMDJ20A, 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 SMDJ20A part is unused and in its original packaging.
Return procedure for SMDJ20A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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