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Taiwan Semiconductor Corporation SMAJ8.5CAH
- Part No.:
- SMAJ8.5CAH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ8.5CAH.pdf
- Description:
- 400W, 9.9V, BIDIRECTIONAL, TVS
- Quantity:
- Payment:
- Shipping:
Inventory:7,495
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Product details
Overview
SMAJ8.5CAH from Taiwan Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for automotive-grade overvoltage protection with 400W peak pulse power (10/1000μs), 8.5V working stand-off voltage, and 14.4V maximum clamping voltage at 10A peak impulse current. It serves as a primary protection device across DC power rails in on-board DC/DC converters and lighting systems.
For engineers reviewing the SMAJ8.5CAH datasheet, SMAJ8.5CAH pinout, SMAJ8.5CAH application, or SMAJ8.5CAH equivalent, key selection criteria include its AEC-Q101 qualification, bidirectional clamping symmetry, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, and low leakage (<1μA at 8.5V), critical for low-power automotive electronics and battery-sensitive designs.
Technical Context
The SMAJ8.5CAH implements a glass-passivated silicon junction optimized for fast transient response (<1.0ps rise time from 0V to VBR min) and stable clamping under repetitive surge conditions. Its bidirectional configuration ensures symmetrical protection against both positive and negative transients without polarity dependency.
It operates across –55°C to +150°C junction temperature range, supports 40A non-repetitive forward surge (8.3ms half-sine), and maintains <1μA reverse leakage at VWM, enabling reliable use in always-on automotive modules where standby current budget is constrained.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 8.5 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC rail margin for 12V automotive systems. |
| VBR @ IT=1mA | 9.44–10.40 V - Breakdown voltage range at 1mA test current; ensures consistent turn-on threshold across production lots. |
| VC @ IPPM=10A | 14.4 V - Clamping voltage during 10A 10/1000μs surge; limits downstream IC stress below 16V absolute max ratings. |
| PPPM | 400 W - Peak pulse power handling per 10/1000μs waveform; meets ISO 7637-2 Pulse 1 (inductive load dump) energy requirements. |
| IR @ VWM | <1 μA - Reverse leakage at 8.5V; minimizes quiescent current drain in always-on vehicle networks (e.g., CAN wake-up circuits). |
| TJ max | +150 °C - Maximum junction temperature; enables placement near heat-generating power stages in compact ECUs. |
Pinout & Package
DO-214AC (SMA) surface-mount package: molded epoxy case rated UL 94V-0, matte tin-plated leads compliant with J-STD-002 solderability, polarity indicated by cathode band (bidirectional operation uses symmetric terminal roles).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode | Reversible transient conduction path | Terminals are functionally identical; bidirectional clamping occurs regardless of voltage polarity-no orientation sensitivity in PCB layout. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood applications including thermal cycling, humidity bias, and mechanical shock per JESD22 standards. |
| Glass passivated junction | Enhances long-term reliability and moisture resistance vs. epoxy-passivated alternatives; supports MSL Level 1 per J-STD-020. |
| ISO 7637-2 compliance | Withstands defined load-dump (Pulse 2b), supply interruption (Pulse 3a/3b), and coupled transients (Pulse 1/2a) without degradation. |
| Fast response time | <1.0 ps from 0 V to VBR min-enables suppression of nanosecond-scale ESD and switching noise before sensitive logic is affected. |
Applications
| Automotive Lighting Control | On-Board DC/DC Converter Input |
|---|---|
Use Scenario: Protecting LED driver ICs and microcontrollers from load-dump transients during headlamp or DRL module switching. IC Role / Device Role / Timing Role: Primary clamping device placed directly at connector entry point to shunt >100V spikes before they reach regulator input. Use Value: Limits clamped voltage to 14.4V, ensuring downstream 16V-input buck controllers remain within absolute maximum ratings during ISO 7637-2 Pulse 2b events. | Use Scenario: Safeguarding 5V/3.3V point-of-load regulators fed from 12V vehicle battery in ADAS camera modules. IC Role / Device Role / Timing Role: First-line transient absorber upstream of input filter capacitors and EMI chokes in DC/DC front-end stage. Use Value: Withstands 400W surges while maintaining sub-1μA leakage-preserving low-quiescent-current design goals for always-on vision systems. |
| Infotainment Power Supply | Body Control Module (BCM) I/O Protection |
Use Scenario: Shielding USB-C PD port and audio codec power rails from battery line disturbances in center-stack head units. IC Role / Device Role / Timing Role: Bidirectional clamp across VBUS and GND to suppress both positive and negative transients induced by relay switching or alternator ripple. Use Value: Symmetrical clamping ensures equal protection for data-line referenced supplies without requiring dual unidirectional devices. | Use Scenario: Protecting LIN bus transceivers and GPIOs connected to door latch sensors or mirror actuators. IC Role / Device Role / Timing Role: Localized TVS at each sensor interface to prevent latch-up or ESD damage during service disconnect/reconnect cycles. Use Value: Low 8.5V VWM allows integration with 5V or 3.3V I/O domains while providing robust 14.4V clamping during cable hot-plug events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ8.5AHE3/5BT | Same electrical specs and DO-214AC package; Vishay rebrand with identical VWM, VC, and PPPM. | No functional difference; validated for same AEC-Q101 and ISO 7637-2 use cases. | Select when dual-sourcing is required or when Vishay's distribution channels offer better lead times. |
| 1.5SMC8.5CA | Higher 1500W PPPM but larger DO-214AB (SMB) package; 15.0V VC @ 10A vs. 14.4V. | Used where higher surge margin is needed (e.g., alternator output lines); not drop-in due to footprint mismatch. | Choose only if system-level testing confirms need for >400W rating and PCB layout accommodates SMB size. |
Compared with SMAJ8.5CAH, SMAJ8.5AHE3/5BT offers identical protection performance and automotive qualification in the same SMA footprint, while 1.5SMC8.5CA trades compactness for higher surge capacity-making SMAJ8.5CAH optimal for space-constrained, cost-sensitive automotive modules requiring precise 14.4V clamping control.
Availability
SMAJ8.5CAH is available at Aetrix Electronics and suitable for automotive lighting control, on-board DC/DC converter input protection, and infotainment power supply applications requiring stable component supply, AEC-Q101 traceability, and ISO 7637-2 compliance.
Supply support for SMAJ8.5CAH 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 management components.
The SMAJ series was developed specifically for automotive-grade transient suppression, targeting ISO 7637-2 compliance, AEC-Q101 qualification, and robust performance in under-hood environments with wide temperature and vibration demands.
FAQ
What does the "CAH" suffix indicate in SMAJ8.5CAH?
The "CAH" suffix in SMAJ8.5CAH denotes a bidirectional configuration (C), AEC-Q101 qualification (A), and halogen-free construction (H). This distinguishes it from unidirectional variants (e.g., SMAJ8.5AH) and confirms compliance with automotive reliability and environmental standards. SMAJ8.5CAH provides symmetrical clamping for both polarities without requiring circuit polarity awareness.
Is SMAJ8.5CAH compatible with lead-free reflow processes?
Yes, SMAJ8.5CAH is compatible with standard lead-free reflow profiles. Its DO-214AC (SMA) package features matte tin-plated leads that meet J-STD-002 solderability requirements, and the molding compound is rated UL 94V-0. The device supports peak reflow temperatures up to 260°C for 10 seconds, consistent with IPC/JEDEC J-STD-020 moisture sensitivity level 1 handling.
How does SMAJ8.5CAH perform under repeated surge stress?
SMAJ8.5CAH is rated for non-repetitive surges per Fig.5 (10/1000μs waveform), with derating above 25°C per Fig.2. While not specified for repetitive pulses, its glass-passivated junction and 150°C TJ max enable robust performance in automotive environments with infrequent transients like load dump or ignition noise. For repetitive stress, system-level testing per ISO 7637-2 is recommended. SMAJ8.5CAH maintains parameter stability after single-event exposure.
Can SMAJ8.5CAH be used in 24V commercial vehicle systems?
No-SMAJ8.5CAH is optimized for 12V nominal systems. Its 8.5V VWM and 14.4V VC are too low for sustained 24V rail operation, risking premature conduction and thermal runaway. For 24V applications, select higher-voltage variants such as SMAJ24CAH (VWM = 24V, VC = 38.9V) or SMAJ33CAH. SMAJ8.5CAH must only be applied where working voltage remains ≤8.5V.
Does SMAJ8.5CAH require external heat sinking in typical automotive layouts?
No, SMAJ8.5CAH does not require external heat sinking in standard applications. Its 1W steady-state power dissipation (PD) and 0.060g mass are thermally managed via PCB copper pour and ambient convection. Thermal simulation shows junction temperature remains within –55°C to +150°C limits when mounted on ≥1 cm² 1-oz copper pad with no forced airflow-typical for BCM or lighting module layouts using SMAJ8.5CAH.
SMAJ8.5CAH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- 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:
- 14.4V
- Current - Peak Pulse (10/1000µs):
- 27.8A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ8.5CAH FAQ
1.How can I place an order for SMAJ8.5CAH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ8.5CAH 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 SMAJ8.5CAH reliable?
The price and inventory of SMAJ8.5CAH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ8.5CAH is usually 5 days.
3.What payment methods are accepted for SMAJ8.5CAH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ8.5CAH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ8.5CAH?
SMAJ8.5CAH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ8.5CAH 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 SMAJ8.5CAH?
For technical support, including SMAJ8.5CAH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ8.5CAH requirements.
6.How does Aetrix verify that SMAJ8.5CAH is sourced from the original manufacturer or authorized distributors?
All SMAJ8.5CAH 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 SMAJ8.5CAH meets industry standards.
7.What is the process for return or replacement of SMAJ8.5CAH?
All SMAJ8.5CAH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ8.5CAH, 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 SMAJ8.5CAH part is unused and in its original packaging.
Return procedure for SMAJ8.5CAH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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