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Taiwan Semiconductor Corporation SMAJ90AH
- Part No.:
- SMAJ90AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ90AH.pdf
- Description:
- TVS DIODE 90VWM 146VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:8,373
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Product details
Overview
SMAJ90AH from Taiwan Semiconductor is a unidirectional 400W transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for automotive-grade overvoltage protection. It features a 90V working stand-off voltage (VWM), 100–111V breakdown range (VBR), 146V clamping voltage at 2.1A peak impulse current, and AEC-Q101 qualification for under-hood electronics.
For engineers reviewing the SMAJ90AH datasheet, SMAJ90AH pinout, SMAJ90AH application, or SMAJ90AH equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, moisture sensitivity level (MSL 1), and compatibility with automated SMT placement in DC/DC converters and lighting systems.
Technical Context
The SMAJ90AH operates as a unidirectional avalanche diode with glass-passivated junction, delivering sub-1ps response time from 0 V to VBR min. Its 150°C maximum junction temperature and -55°C to +150°C operating range support harsh automotive environments.
It meets ISO 7637-2 immunity requirements for load dump and inductive switching transients, with 400W peak pulse power (10/1000μs waveform) derated above 25°C ambient per Fig.2. Steady-state power dissipation is 1W, and forward surge rating is 40A (8.3ms half-sine).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 90 V - Maximum continuous reverse voltage before leakage exceeds 1 µA; defines system operating margin |
| VBR @ IT=1mA | 100–111 V - Breakdown threshold at 1 mA test current; ensures reliable turn-on during transients |
| VC @ IPPM | 146 V - Clamped voltage at 2.1 A peak impulse current; limits downstream IC stress during ISO 7637-2 pulses |
| PPPM (10/1000μs) | 400 W - Peak transient energy handling capacity; supports automotive load-dump suppression |
| IR @ VWM | <1 µA - Reverse leakage at rated stand-off; minimizes quiescent power loss in battery-powered systems |
| Package | DO-214AC (SMA) - Surface-mount outline with 0.060 g mass; compatible with J-STD-002 soldering and JESD201 Class 2 whisker resistance |
Pinout & Package
DO-214AC (SMA) package: cathode-banded unidirectional configuration with two terminals - anode and cathode - mounted on a molded epoxy body meeting UL 94V-0 flammability rating. Matte tin-plated leads ensure solderability and reliability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point in forward bias | Connected to ground or low-side return path; enables clamping when cathode voltage exceeds VWM + VBR |
| Cathode | Current exit point in forward bias; marked with band | Connected to protected line (e.g., 12V rail); absorbs transient energy by avalanching into anode |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control units and body electronics per stress test requirements |
| Glass passivated junction | Enhances long-term stability and reduces parameter drift under thermal cycling and humidity exposure |
| Fast response time <1 ps | Enables suppression of nanosecond-scale ESD and fast-rising load-dump edges before downstream IC damage occurs |
| Meets ISO 7637-2 Pulse 1/2a/2b/3a/3b | Guarantees robustness against real-world automotive transients including battery disconnect and inductive switch-off events |
| MSL Level 1 (per J-STD-020) | Allows unlimited floor life and reflow without baking; simplifies SMT line integration and inventory management |
Applications
| Switching Mode Power Supply (SMPS) | On-board DC/DC Converter |
|---|---|
Use Scenario: Protection of primary-side MOSFET gate drivers and secondary-side rectifiers against flyback spikes and input surges. IC Role / Device Role / Timing Role: Unidirectional TVS placed across input rails or across transformer windings to clamp transient overvoltages. Use Value: Limits peak voltage to 146 V during 400W transients, preventing gate oxide rupture and rectifier avalanche failure. | Use Scenario: Input rail protection in 48V-to-12V or 12V-to-5V automotive DC/DC modules exposed to load dump. IC Role / Device Role / Timing Role: Standoff protector on high-side input, triggered only during >90V excursions to preserve efficiency during normal operation. Use Value: Withstands ISO 7637-2 Pulse 5a (load dump) up to 120V for 400ms while maintaining <1 µA leakage at 90V. |
| Lighting Application | Adapters |
Use Scenario: Overvoltage safeguard for LED driver ICs and MOSFETs in headlamp and interior lighting modules. IC Role / Device Role / Timing Role: Cathode-connected to LED string supply rail; conducts only during transient overvoltage events. Use Value: Clamps 10/1000μs transients to ≤146 V, protecting sensitive PWM controllers and current-sense amplifiers. | Use Scenario: Input-stage surge protection in AC/DC wall adapters used in infotainment and telematics subsystems. IC Role / Device Role / Timing Role: Primary-side TVS between bridge rectifier output and bulk capacitor to absorb line-induced surges. Use Value: Handles 400W peak power without degradation, enabling compliance with IEC 61000-4-5 Level 4 (4 kV) when combined with MOVs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ90H | Higher VBR (100–122 V) and higher VC (160 V); same VWM (90 V) and PPPM (400 W) | Less precise clamping; higher let-through voltage may stress downstream 100V-rated components | Select SMAJ90H only if tighter clamping tolerance is not required and legacy design uses older revision |
| SMBJ90AH | Same VWM (90 V), VBR (100–111 V), and VC (146 V), but in larger DO-214AA (SMB) package with 600W PPPM rating | Higher power handling allows longer-duration transients; footprint incompatible with SMA layout | Choose SMBJ90AH when system-level testing reveals 400W insufficient for worst-case ISO 7637-2 Pulse 5a repetition |
Compared with SMAJ90H and SMBJ90AH, the SMAJ90AH delivers optimal balance of tight clamping (146 V), AEC-Q101 qualification, and DO-214AC footprint-making it preferred for space-constrained, high-reliability automotive modules where both precision and manufacturability matter.
Availability
SMAJ90AH is available at Aetrix Electronics and suitable for automotive power conversion, lighting control, and adapter protection requiring stable component supply across production lifecycles.
Supply support for SMAJ90AH 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 power devices.
The SMAJ series was developed specifically for AEC-Q101-compliant automotive transient suppression, targeting under-hood and chassis-mounted electronics subject to ISO 7637-2 and ISO 16750-2 stress conditions.
FAQ
What is the clamping voltage of SMAJ90AH and how is it measured?
The SMAJ90AH has a maximum clamping voltage (VC) of 146 V, measured at 2.1 A peak impulse current (IPPM) using a standardized 10/1000 μs double-exponential waveform per IEC 61000-4-5. This value reflects the actual voltage seen by protected circuitry during transient events and is guaranteed across temperature and production lots.
Is SMAJ90AH suitable for bidirectional transient protection?
No, SMAJ90AH is a unidirectional TVS diode intended for DC rail protection with defined polarity. For bidirectional applications such as AC lines or data bus protection, use SMAJ90AH's bipolar counterpart SMAJ90CH or SMAJ90CAH, which feature symmetrical breakdown in both directions.
Does SMAJ90AH meet automotive qualification standards?
Yes, SMAJ90AH is AEC-Q101 qualified and tested for temperature cycling, humidity bias, mechanical shock, and board flex per the standard. It also meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements, making it suitable for engine control, body electronics, and ADAS power domains.
What is the maximum operating temperature for SMAJ90AH?
The SMAJ90AH has a maximum junction temperature (TJ) of +150°C and a storage temperature range of -55°C to +150°C. Its thermal resistance (RθJA) is optimized for DO-214AC mounting on standard FR-4 PCBs with recommended pad layout per TSC datasheet Figure 6.
How does SMAJ90AH differ from SMAJ90H in practical design?
SMAJ90AH offers tighter breakdown voltage tolerance (100–111 V vs. 100–122 V for SMAJ90H) and lower clamping voltage (146 V vs. 160 V), resulting in improved protection margin for 100V-rated downstream components. Both share identical VWM (90 V), package, and AEC-Q101 qualification, but SMAJ90AH provides more predictable transient response.
SMAJ90AH 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:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 90V
- Voltage - Breakdown (Min):
- 100V
- Voltage - Clamping (Max) @ Ipp:
- 146V
- Current - Peak Pulse (10/1000µs):
- 2.1A
- 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)
SMAJ90AH FAQ
1.How can I place an order for SMAJ90AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ90AH 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 SMAJ90AH reliable?
The price and inventory of SMAJ90AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ90AH is usually 5 days.
3.What payment methods are accepted for SMAJ90AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ90AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ90AH?
SMAJ90AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ90AH 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 SMAJ90AH?
For technical support, including SMAJ90AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ90AH requirements.
6.How does Aetrix verify that SMAJ90AH is sourced from the original manufacturer or authorized distributors?
All SMAJ90AH 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 SMAJ90AH meets industry standards.
7.What is the process for return or replacement of SMAJ90AH?
All SMAJ90AH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ90AH, 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 SMAJ90AH part is unused and in its original packaging.
Return procedure for SMAJ90AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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