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Taiwan Semiconductor Corporation SMAJ45AH
- Part No.:
- SMAJ45AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ45AH.pdf
- Description:
- TVS DIODE 45VWM 72.7VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,895
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Product details
Overview
SMAJ45AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for overvoltage protection in DC power rails and signal lines. It features a 45 V working stand-off voltage (VWM), 50.0–55.3 V breakdown voltage (VBR), 72.7 V maximum clamping voltage (VC) at 5.5 A peak impulse current, and 400 W peak pulse power rating with 10/1000 µs waveform - suitable for automotive-grade DC/DC converters and industrial SMPS input stages.
For engineers reviewing the SMAJ45AH datasheet, SMAJ45AH pinout, SMAJ45AH application, or SMAJ45AH equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b transients, AEC-Q101 qualification status, DO-214AC (SMA) package compatibility with automated placement, and leakage current ≤1 µA at 45 V.
Technical Context
The SMAJ45AH operates as a unidirectional avalanche diode, leveraging glass-passivated junction technology to achieve sub-1 ps response time from 0 V to VBR min. Its clamping behavior is defined by a single-die structure in DO-214AC packaging, with cathode band polarity marking and matte tin-plated leads compliant with J-STD-002 solderability.
It meets ISO 7637-2 immunity requirements for automotive electronics and supports steady-state power dissipation of 1 W at 25°C, derating linearly above that ambient temperature per Fig.2. Junction temperature range spans −55°C to +150°C, enabling use in under-hood and industrial environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 45 V - Maximum continuous reverse operating voltage before significant leakage begins |
| VBR min/max | 50.0 / 55.3 V @ 1 mA - Ensures reliable turn-on during transients while avoiding false triggering |
| VC @ IPPM | 72.7 V @ 5.5 A - Limits protected circuit voltage during 10/1000 µs surge events |
| PPPM | 400 W (10/1000 µs) - Withstands automotive load dump and inductive switching surges |
| IR @ VWM | ≤1 µA - Minimizes standby power loss in battery-backed or low-power systems |
| TJ max | +150 °C - Enables operation in high-temperature engine control units and industrial drives |
| Package | DO-214AC (SMA) - Standardized SMT footprint compatible with IPC-7351B land patterns |
Pinout & Package
DO-214AC (SMA) package: surface-mount, single-ended, cathode-banded unidirectional configuration. Dimensions conform to JEDEC DO-214AC standard; weight ≈0.060 g; moisture sensitivity level 1 (J-STD-020).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input side of protected line | Connected to source of transient energy (e.g., battery rail or signal line) |
| Cathode | Clamped output / ground reference | Connected to system ground or low-impedance return path; marked by band |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics per stress test requirements including HTOL, TC, and HAST |
| Glass passivated junction | Enhances long-term reliability and stability of VBR and VC under thermal cycling |
| Fast response time <1.0 ps | Clamps transients before downstream ICs experience damaging overvoltage |
| Meets ISO 7637-2 Pulse 1/2a/2b/3a/3b | Complies with automotive EMC immunity standards for battery-supplied systems |
| Halogen-free & RoHS compliant | Fulfills environmental compliance for EU and global OEM supply chains |
Applications
| Automotive Body Control Module | Industrial SMPS Input Stage |
|---|---|
Use Scenario: Protecting LIN bus interface and microcontroller I/O pins from load dump and jump-start transients in BCMs. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between LIN line and ground, triggered within picoseconds of overvoltage onset. Use Value: Limits voltage to ≤72.7 V during ISO 7637-2 Pulse 2b (inductive switch-off), preventing latch-up or gate oxide damage in 5 V logic. | Use Scenario: Safeguarding primary-side controller ICs and MOSFET gates against flyback spikes in 24 V input AC/DC adapters. IC Role / Device Role / Timing Role: Standoff-rated TVS connected across bulk capacitor input to absorb repetitive 400 W surges. Use Value: Maintains 45 V VWM margin above nominal 24 V rail while clamping 10/1000 µs surges to 72.7 V - preserving MOSFET VDS rating and controller UVLO integrity. |
| LED Driver Power Input | On-board DC/DC Converter Protection |
Use Scenario: Shielding constant-current LED driver ICs from battery reversal and alternator ripple in vehicle lighting modules. IC Role / Device Role / Timing Role: Unidirectional TVS mounted at DC input terminal, oriented anode-to-rail, cathode-to-ground. Use Value: Blocks reverse polarity up to −45 V and clamps positive transients to 72.7 V - ensuring driver IC survives cold-crank and jump-start conditions. | Use Scenario: Securing 5 V/3.3 V point-of-load regulators on PCBs subjected to ESD and board-level coupling noise. IC Role / Device Role / Timing Role: Localized TVS placed adjacent to DC/DC converter input pins to shunt fast transients before L-C filtering. Use Value: Sub-1 ps response ensures clamping occurs prior to regulator internal overvoltage shutdown, maintaining uninterrupted power delivery. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ45A | Identical VWM (45 V), VBR (50.0–55.3 V), VC (72.7 V), and DO-214AC package; same AEC-Q101 qualification | No functional difference; validated in identical automotive test profiles including ISO 7637-2 | Select when dual-sourcing is required without layout or validation changes |
| ON Semiconductor SMAJ45A | VWM = 45 V, VBR = 50.0–55.3 V, VC = 72.7 V, same package and AEC-Q101 rating; minor variation in IR spec (≤1 µA vs ≤0.5 µA) | Compatible in all SMAJ45AH use cases; slightly lower leakage may benefit ultra-low-power sleep modes | Prefer for battery-powered modules where <0.5 µA leakage improves shelf life |
Compared with SMAJ45AH, both alternatives offer identical clamping performance and automotive qualification, but Littelfuse SMAJ45A enables seamless second-source procurement, while ON Semiconductor SMAJ45A provides marginally lower leakage for extended battery standby operation.
Availability
SMAJ45AH is available at Aetrix Electronics and suitable for automotive body control modules, industrial switch-mode power supplies, and LED lighting drivers requiring stable component supply across multi-year production cycles.
Supply support for SMAJ45AH 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, serving global automotive, industrial, and consumer markets since 1979.
The SMAJ series is part of TSC's AEC-Q101-qualified TVS portfolio, engineered specifically for robust transient immunity in harsh automotive and industrial power environments.
FAQ
What is the maximum clamping voltage of the SMAJ45AH under standard test conditions?
The SMAJ45AH has a maximum clamping voltage (VC) of 72.7 V when subjected to a 10/1000 µs peak impulse current of 5.5 A, as specified in the official Taiwan Semiconductor datasheet Version A2102. This value defines the upper voltage limit imposed on protected circuits during surge events and is critical for ensuring downstream ICs remain within safe operating voltage ranges. The SMAJ45AH maintains this clamping performance across its full operating temperature range.
Is the SMAJ45AH suitable for bidirectional transient protection?
No, the SMAJ45AH is a unidirectional TVS diode intended only for protection against positive-polarity transients on grounded systems. For bidirectional applications, Taiwan Semiconductor specifies devices with CH or CAH suffixes (e.g., SMAJ45CH). Using SMAJ45AH in reverse-biased configurations risks permanent junction damage due to lack of reverse breakdown specification - always verify polarity alignment in schematic and layout for SMAJ45AH.
Does the SMAJ45AH meet automotive qualification standards?
Yes, the SMAJ45AH is explicitly AEC-Q101 qualified per the Taiwan Semiconductor datasheet, confirming compliance with stress tests including high-temperature operating life, temperature cycling, and humidity testing. It also meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b immunity requirements - making it suitable for use in automotive ECUs, lighting modules, and body control units where reliability under harsh electrical environments is mandatory.
What is the leakage current specification for SMAJ45AH at its working voltage?
The SMAJ45AH exhibits a maximum reverse leakage current (IR) of 1 µA when biased at its rated working stand-off voltage of 45 V, measured at 25°C. This low leakage supports energy-efficient designs, especially in always-on or battery-powered systems where quiescent current directly impacts runtime. The specification remains valid across the full −55°C to +150°C junction temperature range, with typical IR remaining well below 1 µA at lower temperatures.
What package type does the SMAJ45AH use, and is it compatible with automated assembly?
The SMAJ45AH uses the DO-214AC (SMA) surface-mount package, featuring matte tin-plated leads compliant with J-STD-002 solderability requirements and optimized for high-speed pick-and-place equipment. Its standardized footprint, moisture sensitivity level 1 (per J-STD-020), and glass passivated chip junction make it fully compatible with reflow soldering processes and automated manufacturing lines - eliminating manual handling or special process adjustments for SMAJ45AH integration.
SMAJ45AH 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):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.7V
- Current - Peak Pulse (10/1000µs):
- 5.5A
- 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)
SMAJ45AH FAQ
1.How can I place an order for SMAJ45AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ45AH 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 SMAJ45AH reliable?
The price and inventory of SMAJ45AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ45AH is usually 5 days.
3.What payment methods are accepted for SMAJ45AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ45AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ45AH?
SMAJ45AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ45AH 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 SMAJ45AH?
For technical support, including SMAJ45AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ45AH requirements.
6.How does Aetrix verify that SMAJ45AH is sourced from the original manufacturer or authorized distributors?
All SMAJ45AH 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 SMAJ45AH meets industry standards.
7.What is the process for return or replacement of SMAJ45AH?
All SMAJ45AH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ45AH, 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 SMAJ45AH part is unused and in its original packaging.
Return procedure for SMAJ45AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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