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Diodes Incorporated SMAJ8.5A-13
- Part No.:
- SMAJ8.5A-13
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ8.5A-13.pdf
- Description:
- TVS DIODE 8.5VWM 14.4VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:9,277
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Product details
Overview
SMAJ8.5A-13 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power lines and signal interfaces. It features a 8.5V reverse standoff voltage, 9.44–10.4V breakdown range at 1mA test current, 14.4V max clamping voltage at 27.7A peak pulse current, and operates from –55°C to +150°C junction temperature - deployed in automotive infotainment power rails and industrial sensor I/O protection.
For engineers reviewing the SMAJ8.5A-13 datasheet, SMAJ8.5A-13 pinout, SMAJ8.5A-13 application, or SMAJ8.5A-13 equivalent, key selection criteria include clamping voltage margin vs. protected IC VDD, peak pulse current capability under ISO 7637-2 Pulse 1/2a, unidirectional polarity requirement, and SMA package thermal dissipation limits in high-density PCB layouts.
Technical Context
This TVS diode uses a glass-passivated silicon junction optimized for fast response (<1 ps typical) to transient events such as ESD (IEC 61000-4-2), EFT (IEC 61000-4-4), and surge (IEC 61000-4-5). Its unidirectional configuration provides low-leakage reverse blocking (10 µA max @ 8.5V) while enabling forward conduction during negative transients only when used with external biasing.
The device complies with JEDEC-standard 8.3 ms half-sine surge testing (4 pulses/min max duty cycle) and derates linearly above 25°C ambient per Fig. 1 of DS19005 Rev. 12–2. Clamping performance is specified at TJ = 25°C with terminals held at ambient - critical for layout-dependent thermal management in sustained surge conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400 W - sustains single 8.3 ms surges up to 27.7 A without failure under defined thermal conditions |
| Reverse Standoff Voltage (VRWM) | 8.5 V - maximum continuous DC or RMS voltage before significant leakage; sets minimum operating margin for protected circuit |
| Breakdown Voltage (VBR) | 9.44–10.4 V @ 1 mA - defines onset of avalanche conduction; tight tolerance enables predictable turn-on timing |
| Max Clamping Voltage (VC) | 14.4 V @ 27.7 A - upper limit of voltage seen by downstream IC during worst-case surge; determines required IC overvoltage rating |
| Reverse Leakage Current | 10 µA @ 8.5 V - ensures minimal standby power loss and signal integrity in high-impedance monitoring paths |
| Operating Temperature Range | –55°C to +150°C - supports under-hood automotive, motor drive control, and industrial PLC environments |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with UL 94V-0 flammability rating, cathode band polarity indicator, and 0.064 g mass. Terminals are solderable per MIL-STD-202, Method 208.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current sink path during positive surges | Connected to protected line; conducts avalanche current to ground when VLINE > VC |
| Cathode | Reference node / ground connection | Must be low-inductance path to system ground plane; determines clamping reference potential |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated die construction | Enables stable, repeatable avalanche characteristics over lifetime and temperature cycling |
| 400W peak pulse power rating | Meets ISO 7637-2 Pulse 1 (–100 V/0.5 Ω) and Pulse 2a (+100 V/2 Ω) without degradation |
| Fast response time (<1 ps) | Clamps transients before sensitive logic or analog circuitry experiences overstress |
| RoHS-compliant matte tin finish | Supports lead-free reflow profiles (J-STD-020C Level 1) without solder joint reliability risk |
Applications
| Automotive Body Control Module (BCM) Power Input | Industrial RS-485 Transceiver Protection |
|---|---|
Use Scenario: 12 V battery-supplied BCM subjected to load dump (ISO 16750-2) and alternator ripple. IC Role / Device Role / Timing Role: Primary clamping element on main VBAT rail; absorbs energy before LDO input stage. Use Value: Limits rail voltage to ≤14.4 V during 35 V/100 ms load dump event, preventing LDO thermal shutdown and MCU brownout. | Use Scenario: RS-485 node exposed to cable-induced surges in factory automation networks. IC Role / Device Role / Timing Role: First-line protection on A/B differential lines; shunts common-mode transients to ground. Use Value: Clamps ±1 kV EFT bursts to <15 V peak, preserving transceiver data integrity and avoiding bus lockup. |
| Smart Meter AC-DC Auxiliary Supply | Medical Patient Monitor Sensor Interface |
Use Scenario: Auxiliary 5 V supply derived from rectified mains, subject to lightning-induced surges. IC Role / Device Role / Timing Role: Secondary overvoltage clamp after MOV primary stage; handles residual fast-rising spikes. Use Value: Suppresses 500 V/10 µs transients to <15 V, protecting isolated DC-DC controller ICs with 16 V abs max rating. | Use Scenario: Analog front-end for ECG electrode inputs exposed to defibrillation recovery transients. IC Role / Device Role / Timing Role: High-impedance, low-capacitance protector on instrumentation amplifier inputs. Use Value: Delivers <15 pF junction capacitance (Fig. 2), minimizing signal distortion while clamping 10 kV ESD to safe levels. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ8.5CA-13 | Bi-directional version; symmetric clamping for AC-coupled or bidirectional signal lines | Required where protected line swings both above and below ground (e.g., audio, USB D+/D–) | Select only if polarity reversal or AC signal protection is needed; adds ~20% cost and slightly higher leakage |
| SMBJ8.5A-13 | Same electrical specs but SMB package (higher thermal mass, 600 W PPK) | Better suited for high-energy surges where board space allows larger footprint | Choose when surge energy exceeds 400 W capability or when thermal relief via PCB copper is limited |
Compared with SMAJ8.5CA-13 and SMBJ8.5A-13, the SMAJ8.5A-13 offers optimal balance of compact size, precise unidirectional clamping, and proven reliability in space-constrained 12 V DC systems - making it preferred for automotive body electronics and industrial I/O modules where polarity is fixed and board area is premium.
Availability
SMAJ8.5A-13 is available at Aetrix Electronics and suitable for automotive body electronics, industrial communication interfaces, smart meter auxiliary supplies, and medical sensor front-ends requiring stable component supply across multi-year production cycles.
Supply support for SMAJ8.5A-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 the Americas.
The SMAJ series belongs to Diodes' transient voltage suppression portfolio, engineered specifically for robust, standardized overvoltage protection in automotive, industrial, and consumer power and interface circuits - emphasizing reliability under harsh electrical stress and long-term parametric stability.
FAQ
What is the maximum allowable mounting temperature during reflow for SMAJ8.5A-13?
The device is rated for lead-free reflow per J-STD-020C Level 1, with peak temperature up to 260°C for ≤30 seconds. Preheat ramp rate must not exceed 3°C/s, and time above 217°C shall be 60–150 seconds. Thermal profile validation is required for each PCB assembly process due to package thermal mass and board copper density effects.
Can SMAJ8.5A-13 be used in parallel to increase surge current handling?
No - paralleling TVS diodes is not recommended due to mismatched avalanche turn-on voltages causing current imbalance and premature failure of one device. For higher current capability, select a single higher-rated part like SMBJ8.5A-13 or use staged protection (MOV + TVS) instead.
Does SMAJ8.5A-13 meet AEC-Q200 stress testing requirements?
No - SMAJ8.5A-13 is not AEC-Q200 qualified. While widely used in automotive applications, it lacks the extended temperature cycling, humidity bias, and mechanical shock validation required for AEC-Q200 Grade 2 (–40°C to +105°C) or Grade 1 (–40°C to +125°C). For Q200 compliance, consider Diodes' AEC-Q200-qualified P4SMAJ8.5A series.
How does junction capacitance affect its use in high-speed data lines?
At 1 MHz and 0 V bias, typical junction capacitance is ~12 pF (Fig. 2), rising to ~25 pF at 5 V reverse bias. This limits use to signals ≤10 Mbps (e.g., CAN, LIN, UART); for USB 2.0 or Ethernet, lower-capacitance TVS arrays or specialized ESD protection ICs are required to avoid signal integrity degradation.
SMAJ8.5A-13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 8.5V
- Voltage - Breakdown (Min):
- 9.44V
- Voltage - Clamping (Max) @ Ipp:
- 14.4V
- Current - Peak Pulse (10/1000µs):
- 27.8A
- 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)
SMAJ8.5A-13 FAQ
1.How can I place an order for SMAJ8.5A-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ8.5A-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 SMAJ8.5A-13 reliable?
The price and inventory of SMAJ8.5A-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ8.5A-13 is usually 5 days.
3.What payment methods are accepted for SMAJ8.5A-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ8.5A-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ8.5A-13?
SMAJ8.5A-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ8.5A-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 SMAJ8.5A-13?
For technical support, including SMAJ8.5A-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ8.5A-13 requirements.
6.How does Aetrix verify that SMAJ8.5A-13 is sourced from the original manufacturer or authorized distributors?
All SMAJ8.5A-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 SMAJ8.5A-13 meets industry standards.
7.What is the process for return or replacement of SMAJ8.5A-13?
All SMAJ8.5A-13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ8.5A-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 SMAJ8.5A-13 part is unused and in its original packaging.
Return procedure for SMAJ8.5A-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ8.5A-13 Tags
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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