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Diodes Incorporated SMAJ20A-13
- Part No.:
- SMAJ20A-13
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ20A-13.pdf
- Description:
- TVS DIODE 20VWM 32.4VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:3,087
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Product details
Overview
SMAJ20A-13 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power rails and signal lines. It features a 20V reverse standoff voltage (VRWM), 22.2–24.5V breakdown voltage (VBR) at 1mA, 32.4V maximum clamping voltage (VC) at 12.3A peak pulse current (IPP), and operates from –55°C to +150°C.
For engineers reviewing the SMAJ20A-13 datasheet, SMAJ20A-13 pinout, SMAJ20A-13 application, or SMAJ20A-13 equivalent, key selection criteria include clamping performance under 8.3ms surge waveforms, unidirectional polarity for DC-biased circuits, RoHS-compliant SMA package compatibility, and steady-state power dissipation up to 1.0W at TL = 75°C.
Technical Context
This TVS diode uses glass-passivated silicon junction construction to achieve fast response time (<1ps) and stable clamping during transient events such as ESD, lightning-induced surges, and inductive switching spikes. Its unidirectional configuration enables integration into polarized DC supply paths without reverse conduction risk.
The device complies with JEDEC-standard 8.3ms half-sine surge testing (IFSM = 40A), supports 4-pulse-per-minute duty cycle, and maintains clamping integrity across ambient temperatures from –55°C to +150°C with derated peak power above 25°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W - sustains single 8.3ms surge without failure under defined test conditions |
| Reverse Standoff Voltage (VRWM) | 20V - maximum continuous DC or RMS voltage before significant leakage |
| Breakdown Voltage (VBR) | 22.2–24.5V @ 1mA - precise threshold where avalanche conduction begins |
| Clamping Voltage (VC) | 32.4V @ IPP = 12.3A - limits downstream circuit voltage during surge |
| Peak Pulse Current (IPP) | 12.3A - maximum non-repetitive surge current it can shunt safely |
| Operating Temperature | –55°C to +150°C - suitable for automotive engine compartments and industrial control enclosures |
| Steady-State Power | 1.0W @ TL = 75°C - defines thermal limit for continuous dissipation at lead temperature |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with UL 94V-0 flammability rating, cathode band polarity indicator, and moisture sensitivity level 1 per J-STD-020C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry during forward conduction | Connected to protected line's lower potential side in unidirectional configuration |
| Cathode | Current exit during forward conduction; clamping node | Connected to system ground or reference rail; carries full surge current during clamping |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated die | Ensures stable VBR tolerance and long-term reliability under thermal cycling |
| 400W peak pulse rating | Provides robust protection against IEC 61000-4-5 Level 4 (4kV/2Ω) surges |
| Fast response time | Sub-nanosecond turn-on minimizes overshoot before clamping engages |
| RoHS-compliant finish | Matte tin plating meets EU Directive 2011/65/EU with exemptions applied |
| SMA surface-mount package | Enables automated assembly and high-density PCB layout in space-constrained designs |
Applications
| Automotive Power Rail Protection | Industrial PLC I/O Module |
|---|---|
Use Scenario: 12V battery-fed ECUs exposed to load dump transients up to 35V. IC Role / Device Role / Timing Role: Primary clamping element placed between power input and DC-DC converter input. Use Value: Limits voltage to ≤32.4V during 12.3A surge, preventing damage to downstream regulators rated for 36V max input. | Use Scenario: 24V digital input channels receiving signals from field sensors in factory automation. IC Role / Device Role / Timing Role: Unidirectional TVS on each channel to absorb induced surges from relay coil switching. Use Value: Clamps transients within 1ns, preserving signal integrity and avoiding false triggering of microcontroller GPIOs. |
| Telecom Power Interface | Medical Equipment DC Supply |
Use Scenario: -48V telecom rectifier output feeding backplane distribution. IC Role / Device Role / Timing Role: Secondary overvoltage clamp after upstream MOV-based protection. Use Value: Provides precise 32.4V clamping with low leakage (<5µA), ensuring stable bias for monitoring ICs. | Use Scenario: Isolated 5V/12V auxiliary supplies powering analog front-end circuitry. IC Role / Device Role / Timing Role: Final-stage TVS on low-noise LDO inputs to suppress coupling from adjacent switching regulators. Use Value: Low capacitance (<50pF) avoids degrading ADC reference stability or op-amp bandwidth. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ20A-TP from Microchip | Same VRWM (20V), slightly higher VC (33.2V), identical IPP (12.3A), same SMA package | Qualified to AEC-Q101 but not automotive-grade marking; tighter VBR tolerance (±5%) | Select when AEC-Q101 qualification is required and ±5% VBR consistency is critical |
| P6SMB20A from ON Semiconductor | Same VRWM (20V), identical VC (32.4V), same IPP (12.3A), but larger SMB package (4.6 × 3.9mm vs SMA 4.5 × 2.7mm) | Higher thermal mass allows marginally better steady-state dissipation but occupies 40% more board area | Select when PCB layout permits larger footprint and legacy SMB footprint reuse is prioritized |
Compared with SMAJ20A-13, SMAJ20A-TP offers tighter VBR control for precision clamping, while P6SMB20A trades compactness for thermal robustness-choice depends on board space constraints versus thermal margin requirements.
Availability
SMAJ20A-13 is available at Aetrix Electronics and suitable for automotive body electronics, industrial programmable logic controllers, telecom power interfaces, and medical auxiliary power systems requiring stable component supply and consistent surge immunity performance.
Supply support for SMAJ20A-13 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 SMAJ series belongs to Diodes' transient voltage suppression product line, engineered specifically for high-reliability, surface-mount overvoltage protection in automotive, industrial, and communications infrastructure applications.
FAQ
What is the polarity configuration of SMAJ20A-13?
SMAJ20A-13 is a unidirectional TVS diode, indicated by the absence of the "C" suffix. It conducts only during reverse-biased overvoltage events and blocks forward current like a standard diode. The cathode band marks the terminal that must connect to the system ground or lower-potential reference point.
Does SMAJ20A-13 meet automotive qualification standards?
SMAJ20A-13 is not AEC-Q101 qualified out-of-the-box. However, Diodes Incorporated offers AEC-Q101-qualified variants in the same SMAJ family (e.g., SMAJ20AHE3_A/H) with extended temperature screening and enhanced reliability testing. Standard SMAJ20A-13 is widely used in non-safety-critical automotive subsystems.
How does the clamping voltage change with different surge currents?
Clamping voltage increases nonlinearly with peak pulse current: at 5A IPP, VC ≈ 25.1V; at 10A, VC ≈ 30.8V; at 12.3A (rated), VC = 32.4V. This relationship is defined by the device's dynamic resistance (~0.6Ω) and is documented in the datasheet's VC vs. IPP curve (Figure 3).
Can SMAJ20A-13 be used in bidirectional signal line protection?
No-SMAJ20A-13 is unidirectional and unsuitable for AC or bipolar signal lines. For bidirectional protection, use the "C" variant (e.g., SMAJ20CA-13), which has symmetric clamping in both directions and no cathode band marking. Using SMAJ20A-13 on AC lines risks forward conduction and failure during negative half-cycles.
SMAJ20A-13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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):
- 12.3A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- Yes
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMAJ)
SMAJ20A-13 FAQ
1.How can I place an order for SMAJ20A-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ20A-13 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 SMAJ20A-13 reliable?
The price and inventory of SMAJ20A-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ20A-13 is usually 5 days.
3.What payment methods are accepted for SMAJ20A-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ20A-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ20A-13?
SMAJ20A-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ20A-13 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 SMAJ20A-13?
For technical support, including SMAJ20A-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ20A-13 requirements.
6.How does Aetrix verify that SMAJ20A-13 is sourced from the original manufacturer or authorized distributors?
All SMAJ20A-13 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 SMAJ20A-13 meets industry standards.
7.What is the process for return or replacement of SMAJ20A-13?
All SMAJ20A-13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ20A-13, 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 SMAJ20A-13 part is unused and in its original packaging.
Return procedure for SMAJ20A-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ20A-13 Tags
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