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Taiwan Semiconductor Corporation SMAJ120CA
- Part No.:
- SMAJ120CA
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ120CA.pdf
- Description:
- TVS DIODE 120VWM 193VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,774
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Product details
Overview
SMAJ120CA from Taiwan Semiconductor is a bidirectional transient voltage suppressor diode (TVS) designed for robust overvoltage protection in DC power rails and signal lines. It features a 120 V working stand-off voltage (VWM), 133–163 V breakdown voltage (VBR) at 1 mA, 214 V maximum clamping voltage (VC) at 1.4 A peak impulse current, and 400 W peak pulse power rating with 10/1000 µs waveform.
For engineers reviewing the SMAJ120CA datasheet, SMAJ120CA pinout, SMAJ120CA application, or SMAJ120CA equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b transients, DO-214AC (SMA) surface-mount compatibility for automated placement, and bidirectional surge handling capability without polarity sensitivity.
Technical Context
The SMAJ120CA operates as a silicon avalanche diode with glass-passivated junction, enabling fast response (<1.0 ps from 0 V to VBR min) and low leakage (<1 µA at 120 V). Its bidirectional configuration allows symmetric clamping in both polarities, eliminating need for orientation during PCB assembly.
It is rated for 150 °C maximum junction temperature and meets JESD201 Class 2 whisker resistance and J-STD-020 Moisture Sensitivity Level 1. The device sustains 40 A non-repetitive forward surge (8.3 ms half-sine) and complies with RoHS and IEC 61249-2-21 halogen-free requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 120 V - Maximum continuous reverse operating voltage before clamping initiates |
| VBR min/max | 133 V / 163 V at 1 mA - Ensures reliable avalanche conduction onset across process variation |
| VC @ IPPM | 214 V at 1.4 A - Clamped voltage during 10/1000 µs surge, limiting downstream stress |
| PPPM | 400 W - Peak pulse power handling per single 10/1000 µs transient event |
| IR @ VWM | <1 µA - Negligible leakage current at rated stand-off, preserving system efficiency |
| Package | DO-214AC (SMA) - Standard surface-mount outline compatible with IPC-7351B land patterns |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with matte tin-plated leads, polarity indicated by cathode band (not functional in bidirectional SMAJ120CA); weight ≈ 0.060 g; UL 94V-0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (marked end) | Transient return path (bidirectional) | Functions identically as cathode; no polarity dependency - either terminal serves as surge sink |
| Cathode (band end) | Transient return path (bidirectional) | Functions identically as anode; bidirectional symmetry enables orientation-agnostic placement |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable breakdown characteristics and long-term reliability under thermal cycling |
| Sub-1 ps response time | Clamps ESD and fast transients before sensitive ICs experience overstress |
| ISO 7637-2 compliance | Validated for automotive load-dump and inductive-switching immunity testing (Pulse 1/2a/2b/3a/3b) |
| Moisture Sensitivity Level 1 | Enables standard SMT reflow without baking or special handling |
Applications
| Automotive Power Distribution | Industrial DC/DC Converters |
|---|---|
Use Scenario: Protection of 24 V and 48 V battery-fed ECUs against load dump and alternator transients. IC Role / Device Role / Timing Role: Primary clamping element placed at input stage to shunt surge energy before DC/DC controller and LDOs. Use Value: 214 V clamping at 1.4 A limits voltage seen by downstream regulators to safe levels during ISO 7637-2 Pulse 5a events. | Use Scenario: Input rail protection in isolated 48 V-to-12 V industrial DC/DC modules subject to switching noise and coupling surges. IC Role / Device Role / Timing Role: Standoff protector on primary-side bus, absorbing repetitive line-edge spikes without degradation. Use Value: <1 µA leakage at 120 V ensures minimal standby power loss; DO-214AC footprint supports high-density layout. |
| LED Driver Power Inputs | Telecom Power Feeds |
Use Scenario: Overvoltage safeguard for constant-current LED drivers powered from unregulated 120 V AC-derived DC supplies. IC Role / Device Role / Timing Role: First-line defense against rectifier-induced surges and capacitor discharge transients. Use Value: Bidirectional operation accommodates reverse-polarity miswiring during field service without failure. | Use Scenario: Surge suppression on -48 V telecom power feeds exposed to lightning-induced longitudinal surges. IC Role / Device Role / Timing Role: Paired with gas discharge tube (GDT) in hybrid protection circuit for coordinated clamping. Use Value: 400 W peak power rating handles high-energy 10/1000 µs surges while maintaining low clamping voltage relative to system withstand. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ120CA (Bourns) | Same VWM (120 V), but SMB package (DO-214AA); 600 W PPPM rating | Higher power handling suits longer-duration transients; larger footprint may limit layout density | Select when higher surge margin is required and board space permits SMB outline |
| P6SMB120CA (Littelfuse) | Identical electrical specs and DO-214AC package; same 400 W PPPM and 214 V VC | Direct form-fit-function replacement; qualified to AEC-Q101 for automotive use | Preferred for automotive OEM programs requiring AEC-Q101 qualification |
Compared with SMBJ120CA and P6SMB120CA, the SMAJ120CA offers identical clamping performance in a smaller DO-214AC footprint and is optimized for cost-sensitive industrial and lighting applications where AEC-Q101 is not mandated.
Availability
SMAJ120CA is available at Aetrix Electronics and suitable for automotive power distribution, industrial DC/DC converters, LED driver inputs, and telecom power feeds requiring stable component supply and consistent surge immunity performance.
Supply support for SMAJ120CA 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 industrial, computing, and consumer markets since 1979.
The SMAJ series is part of TSC's transient voltage suppressor portfolio, engineered specifically for high-reliability, surface-mount overvoltage protection in automotive, industrial, and lighting systems with stringent ISO 7637-2 compliance requirements.
FAQ
What is the clamping voltage of the SMAJ120CA under a 10/1000 µs surge?
The SMAJ120CA has a maximum clamping voltage (VC) of 214 V when subjected to its rated peak impulse current of 1.4 A using the standardized 10/1000 µs waveform. This value is measured per Figure 5 in the official Taiwan Semiconductor datasheet and defines the upper voltage limit imposed on protected circuitry during surge events.
Is the SMAJ120CA unidirectional or bidirectional?
The SMAJ120CA is a bidirectional TVS diode, indicated by the "CA" suffix. It provides symmetrical clamping in both polarities, meaning it functions identically regardless of voltage polarity across its terminals - ideal for AC-coupled lines or DC systems where reverse connection risk exists.
What package type does the SMAJ120CA use, and is it RoHS compliant?
The SMAJ120CA uses the DO-214AC (SMA) surface-mount package and is fully RoHS compliant and halogen-free per IEC 61249-2-21. Its matte tin-plated leads meet J-STD-002 solderability standards, and the molding compound carries UL 94V-0 flammability rating.
Does the SMAJ120CA meet automotive transient immunity standards?
Yes, the SMAJ120CA meets ISO 7637-2 requirements for Pulse 1, 2a, 2b, 3a, and 3b, making it suitable for protecting electronic control units (ECUs) and power modules in 12 V and 24 V automotive systems against conducted transients from load dump, inductive switching, and battery disconnection.
What is the maximum junction temperature rating for the SMAJ120CA?
The SMAJ120CA has a maximum junction temperature (TJ) rating of +150 °C and a storage temperature range of –55 °C to +150 °C. This rating supports operation in under-hood automotive environments and high-temperature industrial enclosures where thermal management is constrained.
SMAJ120CA 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):
- 120V
- Voltage - Breakdown (Min):
- 133V
- Voltage - Clamping (Max) @ Ipp:
- 193V
- Current - Peak Pulse (10/1000µs):
- 1.6A
- 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)
SMAJ120CA FAQ
1.How can I place an order for SMAJ120CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ120CA 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 SMAJ120CA reliable?
The price and inventory of SMAJ120CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ120CA is usually 5 days.
3.What payment methods are accepted for SMAJ120CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ120CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ120CA?
SMAJ120CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ120CA 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 SMAJ120CA?
For technical support, including SMAJ120CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ120CA requirements.
6.How does Aetrix verify that SMAJ120CA is sourced from the original manufacturer or authorized distributors?
All SMAJ120CA 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 SMAJ120CA meets industry standards.
7.What is the process for return or replacement of SMAJ120CA?
All SMAJ120CA units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ120CA, 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 SMAJ120CA part is unused and in its original packaging.
Return procedure for SMAJ120CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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