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Taiwan Semiconductor Corporation SMAJ150
- Part No.:
- SMAJ150
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ150.pdf
- Description:
- 300W, 185.5V, 10%, UNIDIRECTIONA
- Quantity:
- Payment:
- Shipping:
Inventory:5,398
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Product details
Overview
SMAJ150 from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for robust overvoltage protection in DC power rails. It features a 150 V working stand-off voltage (VWM), 167–204 V breakdown voltage (VBR) at 1 mA test current, and clamps to ≤266 V at 1.1 A peak impulse current under 10/1000 µs waveform - enabling reliable surge suppression in industrial power supplies and automotive ECUs.
For engineers reviewing the SMAJ150 datasheet, SMAJ150 pinout, SMAJ150 application, or SMAJ150 equivalent, key selection criteria include its 400 W peak pulse power rating (10/1000 µs), low leakage (<1 µA at 150 V), -55°C to +150°C operating junction temperature range, and compliance with ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive transients.
Technical Context
The SMAJ150 operates as a unidirectional avalanche diode, leveraging glass-passivated junction technology for stable breakdown behavior and fast response (<1.0 ps from 0 V to VBR min). Its clamping action begins at VBR and limits transient energy by shunting excess current to ground when line voltage exceeds 167 V, maintaining downstream circuit integrity.
Rated for 400 W peak pulse power at TA = 25°C (derated linearly above 25°C per Fig.2), it supports single-pulse surge events up to 1.1 A (10/1000 µs) while sustaining <1 µA reverse leakage at its 150 V stand-off level - making it suitable for high-reliability 24 V–48 V DC systems where low standby loss and precise voltage thresholding are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 150 V - Maximum continuous DC or RMS voltage the device blocks without conduction; defines safe operating margin below clamping onset. |
| VBR @ IT=1 mA | 167–204 V - Measured breakdown voltage range; ensures predictable turn-on within tight tolerance for consistent protection timing. |
| VC @ IPPM=1.1 A | ≤266 V - Clamping voltage under standardized 10/1000 µs surge; determines maximum stress imposed on protected ICs or MOSFETs. |
| PPPM (10/1000 µs) | 400 W - Peak pulse power handling capacity; enables absorption of high-energy transients like load dump or inductive kickback. |
| IR @ VWM | <1 µA - Reverse leakage current at rated stand-off voltage; guarantees minimal quiescent power loss in battery-backed or low-power systems. |
| TJ Operating Range | -55°C to +150°C - Junction temperature range supporting deployment in under-hood automotive, industrial motor drives, and outdoor power electronics. |
| Package | DO-214AC (SMA) - Industry-standard surface-mount outline with matte tin-plated leads; compatible with automated reflow assembly and J-STD-002 solderability. |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with cathode band marking; anode and cathode terminals aligned for standard PCB footprint (see JEDEC MS-013). Matte tin-plated leads meet J-STD-002 solderability and JESD201 Class 2 whisker resistance requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Current entry point during forward conduction; grounded reference in unidirectional TVS configuration | Connected to system ground or low-side return path; establishes reference for clamping action relative to protected rail. |
| Cathode (banded end) | Transient voltage sensing and clamping node | Connected directly to protected line (e.g., 150 V DC input); avalanche conduction initiates here when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable, repeatable breakdown characteristics across temperature and lifetime; eliminates parameter drift due to moisture or contamination. |
| Fast response time <1.0 ps | Enables sub-nanosecond reaction to ESD or fast-rising transients - critical for protecting high-speed logic and analog front-ends. |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Validated performance against automotive-level conducted transients including load dump, supply interruption, and coupled noise. |
| Moisture sensitivity level 1 (J-STD-020) | Allows unlimited floor life before reflow; eliminates baking requirement and simplifies SMT manufacturing logistics. |
| RoHS & halogen-free (IEC 61249-2-21) | Meets global environmental compliance mandates without compromising thermal or electrical performance in high-reliability applications. |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: 150 V DC input rail in programmable logic controller (PLC) power stage exposed to switching surges and field wiring faults. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input and chassis ground to clamp transients before they reach DC/DC controllers and gate drivers. Use Value: Limits voltage excursion to ≤266 V during 400 W surges, preserving 200 V-rated MOSFETs and preventing latch-up in isolated feedback circuits. |
Use Scenario: 12 V–24 V subsystem powered from vehicle battery with risk of load dump (up to 120 V) and jump-start spikes. IC Role / Device Role / Timing Role: Primary overvoltage clamp on BCM main power input, coordinated with upstream fuses and secondary TVS devices. Use Value: Withstands ISO 7637-2 Pulse 5a (load dump) up to 120 V and provides <1 µA leakage to extend battery standby life in always-on modules. |
| Telecom DC/DC Converter Input | Railway Signaling Interface |
Use Scenario: 48 V telecom rectifier output feeding distributed DC/DC converters in base station cabinets subject to lightning-induced surges. IC Role / Device Role / Timing Role: First-line transient suppressor on converter primary side, absorbing energy before it reaches isolation transformers and PWM controllers. Use Value: 400 W peak power rating handles multi-kA induced surges; DO-214AC package allows dense layout near connector entry points. |
Use Scenario: 110 V DC signaling line in railway trackside equipment exposed to traction return currents and electromagnetic coupling. IC Role / Device Role / Timing Role: Standoff-rated TVS on signal conditioning inputs to protect optocouplers and microcontroller GPIOs from sustained overvoltages. Use Value: 150 V VWM provides 10% margin above nominal 110 V rail while clamping to ≤266 V ensures compatibility with 300 V-rated interface ICs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ150A | Lower VBR range (167–185 V), tighter tolerance; clamps to ≤243 V at same 1.1 A test current. | Better suited for designs requiring lower clamping voltage margin and tighter VBR consistency across production lots. | Select SMAJ150A when downstream components have ≤245 V absolute maximum ratings and tighter VBR distribution improves yield. |
| ON Semiconductor SMAJ150 | Identical VWM (150 V), VBR (167–204 V), and VC (≤266 V); minor differences in IR spec (≤1 µA vs. ≤0.5 µA typical). | No functional deviation in protection behavior; validated for same ISO 7637-2 pulses and thermal derating profile. | Drop-in alternative with identical pinout, footprint, and electrical specs - ideal for dual-sourcing or lifecycle continuity planning. |
Compared with SMAJ150, the SMAJ150A offers reduced clamping voltage and tighter VBR control for margin-critical designs, while the ON Semiconductor SMAJ150 delivers full electrical and mechanical equivalence - enabling seamless second-source qualification without layout or firmware changes.
Availability
SMAJ150 is available at Aetrix Electronics and suitable for industrial power supplies, automotive electronic control units, and telecom DC/DC converter inputs requiring stable component supply, long-term lifecycle support, and traceable RoHS-compliant sourcing.
Supply support for SMAJ150 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, and rectifiers with global distribution and AEC-Q200 qualified product lines.
The SMAJ series was developed for high-reliability transient suppression in harsh environments - targeting automotive, industrial, and telecom applications where robustness, low leakage, and ISO 7637-2 compliance are mandatory design requirements.
FAQ
What is the maximum clamping voltage of the SMAJ150 under standard test conditions?
The SMAJ150 has a maximum clamping voltage (VC) of 266 V when subjected to a 10/1000 µs surge waveform at 1.1 A peak impulse current (IPPM), as specified in the Taiwan Semiconductor datasheet revision U2102. This value defines the upper voltage limit imposed on protected circuitry during transient events and is measured with the device mounted on a standard FR-4 PCB per JEDEC guidelines.
Is the SMAJ150 suitable for bidirectional transient protection?
No, the SMAJ150 is a unidirectional TVS diode intended for DC line protection with polarity-sensitive placement. For bidirectional applications such as AC lines or data bus protection, the SMAJ150A variant or dedicated bidirectional parts like SMAJ150CA must be used - the SMAJ150 lacks symmetrical breakdown characteristics and will not conduct in reverse bias beyond its specified leakage.
Does the SMAJ150 meet automotive transient immunity standards?
Yes, the SMAJ150 meets ISO 7637-2 requirements for Pulses 1, 2a, 2b, 3a, and 3b, covering common automotive transients including supply disconnection, load dump simulation, and coupled noise. Its 400 W peak pulse power rating and 150°C junction temperature capability make it suitable for under-hood and body electronics applications per AEC-Q200 recommendations.
What is the thermal derating behavior of the SMAJ150 above 25°C ambient?
The SMAJ150's peak pulse power rating decreases linearly above 25°C ambient temperature, following the derating curve in Figure 2 of the U2102 datasheet. At 85°C ambient, its PPPM drops to approximately 260 W; at 125°C, it falls to ~160 W. Designers must apply this derating when sizing for high-temperature enclosures or proximity to heat sources.
Can the SMAJ150 be used in parallel for higher surge current handling?
Parallel operation of SMAJ150 devices is not recommended due to mismatched VBR tolerances (167–204 V), which cause uneven current sharing and potential thermal runaway. For higher IPPM requirements, select a single higher-rated device (e.g., SM8S150A) or consult Taiwan Semiconductor's application guidance on staged protection topologies using pre- and post-regulator TVS stages.
SMAJ150 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):
- 150V
- Voltage - Breakdown (Min):
- 167V
- Voltage - Clamping (Max) @ Ipp:
- 266V
- Current - Peak Pulse (10/1000µs):
- 1.1A
- 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)
SMAJ150 FAQ
1.How can I place an order for SMAJ150 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ150 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 SMAJ150 reliable?
The price and inventory of SMAJ150 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ150 is usually 5 days.
3.What payment methods are accepted for SMAJ150?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ150 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ150?
SMAJ150 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ150 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 SMAJ150?
For technical support, including SMAJ150 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ150 requirements.
6.How does Aetrix verify that SMAJ150 is sourced from the original manufacturer or authorized distributors?
All SMAJ150 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 SMAJ150 meets industry standards.
7.What is the process for return or replacement of SMAJ150?
All SMAJ150 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ150, 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 SMAJ150 part is unused and in its original packaging.
Return procedure for SMAJ150:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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