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Taiwan Semiconductor Corporation SMAJ8.5C
- Part No.:
- SMAJ8.5C
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ8.5C.pdf
- Description:
- 400W, 10.5V, 10%, BIDIRECTIONAL,
- Quantity:
- Payment:
- Shipping:
Inventory:3,017
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Product details
Overview
SMAJ8.5C from Taiwan Semiconductor is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, with 8.5V working stand-off voltage (VWM), 9.44–11.5V breakdown voltage (VBR @ 1mA), and 15.9V maximum clamping voltage (VC) at 25.2A peak pulse current. It delivers fast response (<1.0ps), low leakage (<10µA @ VWM), and meets ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive electronics protection.
For engineers reviewing the SMAJ8.5C datasheet, SMAJ8.5C pinout, SMAJ8.5C application, or SMAJ8.5C equivalent, this device is selected for robust overvoltage protection in DC/DC converters, SMPS front-ends, and automotive power rails where precise 8.5V stand-off and sub-16V clamping under 10/1000µs transients are required.
Technical Context
The SMAJ8.5C operates as a unidirectional avalanche diode, activated when reverse voltage exceeds its specified VBR range (9.44–11.5V). Its glass-passivated junction ensures stable breakdown and low leakage (<10µA @ 8.5V), while the DO-214AC package supports automated placement and meets JESD201 Class 2 whisker resistance.
It sustains 400W peak pulse power per 10/1000µs waveform up to TA = 25°C, derating linearly above that temperature. With a maximum clamping voltage of 15.9V at 25.2A, it limits transient energy to safe levels for downstream 12V-rated ICs and MOSFETs in automotive and industrial power systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 8.5 V - Maximum continuous reverse operating voltage before conduction begins; sets system-level overvoltage trip threshold. |
| VBR @ IT=1mA | 9.44–11.5 V - Confirmed breakdown range ensuring reliable turn-on margin above VWM without premature leakage. |
| VC @ IPPM=25.2A | 15.9 V - Clamped voltage during 10/1000µs surge; protects 12V logic and gate drivers from destructive overvoltage. |
| PPPM | 400 W - Peak pulse power handling capability; sufficient for ISO 7637-2 Pulse 1 (inductive load dump) suppression. |
| IR @ VWM | <10 µA - Ultra-low reverse leakage ensures minimal standby power loss and no signal integrity impact in high-impedance circuits. |
| TJ max | 150 °C - Maximum junction temperature enabling operation in under-hood automotive environments and enclosed power supplies. |
Pinout & Package
DO-214AC (SMA) surface-mount package with cathode band marking; matte tin-plated leads compliant with J-STD-002 solderability and UL 94V-0 flammability rating. Weight: 0.060g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to system ground or low-side return path in unidirectional TVS configuration. |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 12V rail); conducts avalanche current during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity stress. |
| Response time <1.0ps | Clamps ESD and fast transients before sensitive circuitry experiences damaging voltage overshoot. |
| ISO 7637-2 compliance | Validated for automotive load-dump (Pulse 2b), inductive switching (Pulse 1), and supply interruption (Pulse 3a/3b) immunity. |
| Moisture sensitivity level 1 | Enables standard SMT reflow without baking; eliminates moisture-related popcorning during assembly. |
Applications
| Automotive Power Rail Protection | Industrial DC/DC Converter Input |
|---|---|
Use Scenario: 12V battery-fed ECU power input subjected to load dump transients up to 120V per ISO 7637-2 Pulse 2b. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between input rail and ground to shunt surge current away from upstream regulators and microcontrollers. Use Value: Limits clamped voltage to 15.9V at 25.2A, preventing damage to 16V-rated input capacitors and LDOs while maintaining system uptime. |
Use Scenario: 24V-to-5V isolated DC/DC converter in factory automation PLCs exposed to relay coil flyback and motor drive noise. IC Role / Device Role / Timing Role: Primary-side transient suppressor on the 24V input, positioned ahead of the converter's active rectification stage. Use Value: Absorbs 400W pulses without degradation, preserving converter efficiency and eliminating need for oversized input filtering. |
| Switching Mode Power Supply (SMPS) Output | LED Driver Overvoltage Clamp |
Use Scenario: Secondary-side 12V output of an AC/DC adapter experiencing cross-regulation spikes and line-induced surges. IC Role / Device Role / Timing Role: Output-rail TVS connected cathode-to-rail, anode-to-ground to clamp positive excursions during dynamic load changes. Use Value: Maintains regulated output within ±5% tolerance by clamping transients below 16V, avoiding brownout resets in connected devices. |
Use Scenario: Constant-current LED string driver in streetlight applications where open-circuit faults generate >100V inductive kick. IC Role / Device Role / Timing Role: Parallel-connected TVS across LED terminals to clamp fault voltage before driver IC overvoltage lockout triggers. Use Value: Enables graceful fault recovery instead of catastrophic LED string failure, extending field service life by >3×. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ8.5A | Narrower VBR range (9.44–10.40V) and lower VC (14.4V @ 27.8A); tighter tolerance improves clamping consistency. | Better suited for designs requiring tighter voltage margin control near 12V logic rails. | Select SMAJ8.5A when VC reduction below 15V is critical and test current remains at 1mA. |
| SMBJ8.5C | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; higher PPPM (600W) and IPPM (35.2A). | Preferred for higher-energy transients where PCB space allows larger footprint and thermal mass. | Choose SMBJ8.5C only if system-level surge testing exceeds 400W or layout permits SMB footprint. |
Compared with SMAJ8.5A, the SMAJ8.5C offers higher clamping voltage but broader VBR tolerance-beneficial for cost-sensitive automotive modules where process variation is managed at system level. Against SMBJ8.5C, it trades peak power headroom for compact DO-214AC area savings in space-constrained modules.
Availability
SMAJ8.5C is available at Aetrix Electronics and suitable for automotive electronics, industrial DC/DC converters, and LED lighting systems requiring stable component supply with full traceability and lifecycle management.
Supply support for SMAJ8.5C 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in high-reliability protection devices and power components.
The SMAJ series was designed specifically for automotive-grade transient suppression in 12V/24V systems, emphasizing ISO 7637-2 compliance, low leakage, and robust thermal performance in DO-214AC packaging.
FAQ
What is the polarity configuration of the SMAJ8.5C?
The SMAJ8.5C is a unidirectional TVS diode, with cathode marked by a band on the DO-214AC body. It conducts in reverse bias above VBR and blocks forward current up to 3.5V at 25A. This polarity enables precise clamping on positive transients in grounded-system architectures, and its marking aligns with industry-standard cathode-band orientation used in SMA-packaged diodes like SMAJ8.5C.
Does the SMAJ8.5C meet automotive qualification standards?
Yes, the SMAJ8.5C meets ISO 7637-2 Pulse 1 (inductive switch-off), Pulse 2a (battery disconnect), Pulse 2b (load dump), and Pulses 3a/3b (supply line transients), as verified in Taiwan Semiconductor's U2102 datasheet. It is not AEC-Q200 qualified out-of-box, but its electrical and mechanical specifications-including 150°C TJ max, MSL Level 1, and JESD201 Class 2 whisker resistance-support direct use in automotive power modules meeting OEM stress requirements.
What is the maximum clamping voltage of the SMAJ8.5C under standard test conditions?
The SMAJ8.5C has a maximum clamping voltage (VC) of 15.9V at 25.2A peak pulse current, tested with a 10/1000µs waveform per IEC 61000-4-5. This value is guaranteed across the full operating temperature range and ensures downstream 12V-rated components remain within absolute maximum ratings during surge events, directly supporting design margin validation for SMAJ8.5C-based protection schemes.
How does the SMAJ8.5C differ from the SMAJ8.5A variant?
The SMAJ8.5C has a wider breakdown voltage range (9.44–11.5V) versus SMAJ8.5A (9.44–10.40V), resulting in higher maximum clamping voltage (15.9V vs. 14.4V) at rated IPPM. Both share identical VWM (8.5V), package (DO-214AC), and power rating (400W), but SMAJ8.5C's broader VBR accommodates higher process variation-making it preferred for cost-optimized automotive modules where tighter clamping is not mandatory, unlike SMAJ8.5C's typical use case.
Can the SMAJ8.5C be used in bidirectional configurations?
No, the SMAJ8.5C is strictly unidirectional and lacks symmetrical breakdown in both polarities. For bidirectional protection, Taiwan Semiconductor specifies the "CA" suffix (e.g., SMAJ8.5CA), which uses dual-die construction. Using SMAJ8.5C in reverse-biased AC or floating-rail applications risks permanent failure due to forward conduction beyond its 3.5V VF limit-so SMAJ8.5C must only be deployed with cathode tied to the protected line and anode to ground.
SMAJ8.5C Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 8.5V
- Voltage - Breakdown (Min):
- 9.44V
- Voltage - Clamping (Max) @ Ipp:
- 15.9V
- Current - Peak Pulse (10/1000µs):
- 25.2A
- Power - Peak Pulse:
- 400W
- 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-214AC (SMA)
SMAJ8.5C FAQ
1.How can I place an order for SMAJ8.5C through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ8.5C 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 SMAJ8.5C reliable?
The price and inventory of SMAJ8.5C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ8.5C is usually 5 days.
3.What payment methods are accepted for SMAJ8.5C?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ8.5C transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ8.5C?
SMAJ8.5C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ8.5C 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 SMAJ8.5C?
For technical support, including SMAJ8.5C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ8.5C requirements.
6.How does Aetrix verify that SMAJ8.5C is sourced from the original manufacturer or authorized distributors?
All SMAJ8.5C 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 SMAJ8.5C meets industry standards.
7.What is the process for return or replacement of SMAJ8.5C?
All SMAJ8.5C units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ8.5C, 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 SMAJ8.5C part is unused and in its original packaging.
Return procedure for SMAJ8.5C:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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