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Taiwan Semiconductor Corporation SMAJ85C
- Part No.:
- SMAJ85C
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ85C.pdf
- Description:
- 300W, 104.7V, 10%, BIDIRECTIONAL
- Quantity:
- Payment:
- Shipping:
Inventory:5,697
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Product details
Overview
SMAJ85C from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping fast-rising ESD and surge transients in DC power lines. It features 85 V working stand-off voltage (VWM), 94.4–115 V breakdown voltage (VBR @ 1 mA), 151 V maximum clamping voltage (VC @ 2.0 A), and 400 W peak pulse power (10/1000 µs waveform), making it suitable for protecting 72–96 V industrial power rails and automotive body electronics.
For engineers reviewing the SMAJ85C datasheet, SMAJ85C pinout, SMAJ85C application, or SMAJ85C equivalent, key selection criteria include its unidirectional polarity, 1 µA max reverse leakage at VWM, sub-1 ps response time, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, and DO-214AC mechanical compatibility with automated SMT assembly.
Technical Context
The SMAJ85C operates as a silicon avalanche diode with glass-passivated junction, enabling precise voltage clamping during transient overvoltage events. Its unidirectional configuration provides forward conduction path while suppressing reverse surges up to 151 V at 2.0 A peak impulse current (IPPM).
Designed for 10/1000 µs standard surge waveforms, it delivers 400 W peak pulse power at TA = 25°C and derates linearly above that ambient temperature. The device supports operating junction temperatures from –55°C to +150°C and meets J-STD-020 moisture sensitivity level 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 85 V - Maximum continuous reverse operating voltage before clamping begins; sets safe margin above 72 V nominal rail. |
| VBR min/max | 94.4 V / 115 V @ 1 mA - Confirmed breakdown range ensures reliable turn-on within spec across production lot. |
| VC @ IPPM | 151 V @ 2.0 A - Clamping voltage under 10/1000 µs surge defines worst-case stress on downstream ICs. |
| PPPM | 400 W - Peak pulse power handling capacity per single non-repetitive 10/1000 µs event at 25°C. |
| IR @ VWM | ≤1 µA - Ultra-low reverse leakage preserves efficiency in high-impedance monitoring or standby circuits. |
| Response time | <1.0 ps - Enables suppression of ESD and fast transients before sensitive circuitry is damaged. |
| Package | DO-214AC (SMA) - Industry-standard surface-mount outline with cathode band marking and 0.060 g mass. |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with matte tin-plated leads, polarity indicated by cathode band, compliant with UL 94V-0 and JESD 201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (non-banded end) | Forward current input / Surge return path | Connects to protected line's low-side or ground reference; conducts during forward surge or normal operation. |
| Cathode (banded end) | Clamping node / High-voltage reference | Connected to protected line's high-side; avalanches when reverse voltage exceeds VBR, shunting surge to ground. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity exposure. |
| ISO 7637-2 compliance | Validated for automotive load-dump and inductive-switching transients (Pulse 1, 2a, 2b, 3a, 3b) without external filtering. |
| Automated placement compatibility | DO-214AC footprint and lead coplanarity support high-yield pick-and-place at >25,000 UPH. |
| RoHS & halogen-free | Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU for environmentally constrained applications. |
| J-STD-020 Level 1 rating | Enables reflow soldering without pre-baking; compatible with standard Pb-free reflow profiles (peak ≤260°C). |
Applications
| Industrial Power Rail Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: Protecting 72–96 V DC bus in programmable logic controllers (PLCs) and motor drives against inductive switching spikes and lightning-induced surges. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed across input terminals to clamp transients below system overvoltage threshold. Use Value: Limits clamped voltage to 151 V, ensuring downstream DC/DC converters and microcontrollers remain within absolute maximum ratings. |
Use Scenario: Safeguarding LIN and CAN interface power inputs in BCMs exposed to battery disconnect/load dump events per ISO 7637-2 Pulse 2b. IC Role / Device Role / Timing Role: Primary surge suppression element on 12 V auxiliary supply rail feeding communication ICs and sensors. Use Value: Withstands 400 W peak pulse energy and responds in <1 ps, preventing latch-up or permanent damage to transceivers. |
| LED Streetlight Driver Input | Telecom DC Power Entry |
Use Scenario: Front-end protection for constant-current LED drivers operating from 85–265 VAC rectified outputs (~120 VDC bus). IC Role / Device Role / Timing Role: Standoff-rated TVS absorbing line-to-ground surges during AC mains transients or nearby lightning strikes. Use Value: 85 V VWM allows safe operation above rectified minimum, while 151 V VC prevents overvoltage on primary-side MOSFETs and controllers. |
Use Scenario: Secondary-side DC input protection for 48 V telecom equipment subjected to accidental battery reversal or hot-swap transients. IC Role / Device Role / Timing Role: Unidirectional clamping device on -48 V return path to absorb reverse-polarity energy without forward conduction loss. Use Value: 1 µA leakage at VWM minimizes standby current drain; DO-214AC package enables dense layout near connector entry points. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ85A | VBR = 94.4–104 V (tighter max); VC = 137 V @ 2.2 A; same DO-214AC package and 400 W rating. | Lower clamping voltage improves margin for 100 V-rated components but requires verification of reduced IPPM headroom. | Select SMAJ85A when lower clamping is critical and 2.2 A IPPM suffices; verify layout clearance for identical footprint. |
| ON Semiconductor SMAJ85CA | Bidirectional variant (suffix CA); symmetric VBR and VC in both polarities; otherwise identical electrical specs. | Required only where AC-coupled or polarity-agnostic surge protection is needed (e.g., data lines), not for DC rail clamping. | Use SMAJ85CA only if bidirectional behavior is explicitly required; SMAJ85C remains optimal for unidirectional DC power rails. |
Compared with SMAJ85A and SMAJ85CA, the SMAJ85C offers the highest clamping voltage among the three but delivers the most robust unidirectional DC rail protection with verified 400 W capability, full ISO 7637-2 coverage, and industry-standard DO-214AC manufacturability.
Availability
SMAJ85C is available at Aetrix Electronics and suitable for industrial power rail protection, automotive body control modules, LED driver inputs, and telecom DC power entry requiring stable component supply and full traceability.
Supply support for SMAJ85C 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 TVS diodes, rectifiers, and protection devices since 1979.
The SMAJ series was developed specifically for high-reliability transient suppression in automotive, industrial, and telecom power systems, emphasizing ISO 7637-2 compliance, automated assembly readiness, and extended temperature operation.
FAQ
What is the polarity configuration of the SMAJ85C?
The SMAJ85C is a unidirectional transient voltage suppressor diode, with cathode marked by a band on the DO-214AC package. It conducts in forward bias and clamps reverse transients above its breakdown voltage. This configuration is optimized for DC power line protection where polarity is fixed, unlike bidirectional variants such as SMAJ85CA.
Does the SMAJ85C meet automotive surge immunity standards?
Yes, the SMAJ85C meets ISO 7637-2 requirements for Pulse 1 (inductive load disconnect), Pulse 2a (sudden load removal), Pulse 2b (supply interruption), Pulse 3a (capacitive coupled noise), and Pulse 3b (ground bounce). Its 400 W peak pulse power and sub-1 ps response ensure robust protection in 12 V and 24 V automotive subsystems.
What is the maximum clamping voltage of the SMAJ85C under surge conditions?
The SMAJ85C has a maximum clamping voltage (VC) of 151 V at 2.0 A peak impulse current (IPPM) under the standardized 10/1000 µs waveform. This value defines the upper voltage limit imposed on protected circuitry during a surge event and is guaranteed across the full operating temperature range.
Can the SMAJ85C be used in high-humidity environments?
Yes, the SMAJ85C uses glass-passivated chip junction technology and moisture sensitivity level 1 packaging per J-STD-020, allowing direct placement into reflow ovens without baking. Its UL 94V-0 molding compound and matte tin-plated leads provide long-term stability in humid industrial and outdoor deployments.
How does the SMAJ85C compare to the SMAJ85A in terms of clamping performance?
The SMAJ85C clamps at 151 V @ 2.0 A, whereas the SMAJ85A clamps at 137 V @ 2.2 A. The SMAJ85C offers higher surge current headroom (2.0 A vs. 2.2 A is not directly comparable due to different test conditions), but the SMAJ85A achieves lower clamping voltage. Designers should select SMAJ85C when prioritizing peak current handling and SMAJ85A when minimizing clamped voltage is critical.
SMAJ85C 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):
- 85V
- Voltage - Breakdown (Min):
- 94.4V
- Voltage - Clamping (Max) @ Ipp:
- 151V
- Current - Peak Pulse (10/1000µs):
- 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)
SMAJ85C FAQ
1.How can I place an order for SMAJ85C through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ85C 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 SMAJ85C reliable?
The price and inventory of SMAJ85C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ85C is usually 5 days.
3.What payment methods are accepted for SMAJ85C?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ85C transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ85C?
SMAJ85C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ85C 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 SMAJ85C?
For technical support, including SMAJ85C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ85C requirements.
6.How does Aetrix verify that SMAJ85C is sourced from the original manufacturer or authorized distributors?
All SMAJ85C 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 SMAJ85C meets industry standards.
7.What is the process for return or replacement of SMAJ85C?
All SMAJ85C units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ85C, 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 SMAJ85C part is unused and in its original packaging.
Return procedure for SMAJ85C:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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