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Taiwan Semiconductor Corporation SMAJ15CH
- Part No.:
- SMAJ15CH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ15CH.pdf
- Description:
- TVS DIODE 15VWM 26.9VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,592
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Product details
Overview
SMAJ15CH from Taiwan Semiconductor is a unidirectional 400W transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for robust overvoltage protection in automotive and industrial power rails. It features a 15V working stand-off voltage (VWM), 16.7–20.4V breakdown voltage (VBR), 26.9V clamping voltage (VC) at 14.9A peak pulse current, and AEC-Q101 qualification for automotive reliability.
For engineers reviewing the SMAJ15CH datasheet, SMAJ15CH pinout, SMAJ15CH application, or SMAJ15CH equivalent, this device is selected for DC/DC converter input protection, SMPS line surge suppression, and ISO 7637-2 Pulse 1/2a/3b-compliant automotive electronics where fast clamping (<1.0 ps response), low leakage (<1 µA @ VWM), and 150°C junction operation are critical.
Technical Context
The SMAJ15CH operates as a unidirectional avalanche diode with glass-passivated junction, optimized for transient suppression on positive-rail applications. Its electrical behavior follows standard TVS diode characteristics: reverse-biased operation up to VWM = 15V, sharp avalanche breakdown at VBR (min 16.7V, max 20.4V @ 1mA), and clamps transients to VC ≤ 26.9V at IPPM = 14.9A under 10/1000µs waveform.
It meets ISO 7637-2 Pulse 1 (inductive load dump), Pulse 2a (battery disconnect), and Pulse 3a/3b (capacitive coupling & ignition noise), with moisture sensitivity level 1 and RoHS/halogen-free compliance. Thermal derating begins above TA = 25°C per Fig.2, maintaining 400W peak pulse power only at ambient ≤25°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 15 V - Maximum continuous reverse operating voltage before conduction begins; sets upper limit of protected rail voltage |
| VBR min/max | 16.7 / 20.4 V @ 1 mA - Confirmed avalanche onset range; ensures reliable triggering above nominal system voltage |
| VC @ IPPM | 26.9 V @ 14.9 A - Clamped voltage during 10/1000µs surge; defines maximum stress seen by downstream ICs |
| PPPM | 400 W (10/1000µs) - Peak transient energy handling capacity; supports automotive load-dump and ESD events |
| IR @ VWM | <1 µA - Negligible leakage at rated stand-off; avoids power loss or false triggering in high-impedance circuits |
| TJ max | +150 °C - Enables operation in under-hood automotive environments and thermally constrained PCB layouts |
| Package | DO-214AC (SMA) - Surface-mount outline with cathode band marking; compatible with automated placement and J-STD-002 soldering |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band. Weight ≈ 0.060 g. Meets UL 94V-0 flammability rating and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-voltage return path; forms current path during reverse transient clamp |
| Cathode | High-side connection terminal | Connected to protected line (e.g., +12V rail); conducts avalanche current when voltage exceeds VBR |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per AEC standard |
| Glass-passivated junction | Enhances long-term stability and reduces parameter drift under thermal stress and humidity exposure |
| Clamping response <1.0 ps | Enables protection of high-speed digital interfaces and sensitive analog circuitry against nanosecond-scale transients |
| ISO 7637-2 compliance | Guarantees performance against standardized automotive transients (Pulse 1, 2a, 2b, 3a, 3b) without external filtering |
| Moisture sensitivity level 1 | Eliminates bake requirements prior to reflow; supports standard SMT assembly without special handling |
Applications
| Automotive Power Rail Protection | On-Board DC/DC Converter Input |
|---|---|
Use Scenario: Protecting 12V battery-fed ECUs from load dump and alternator ripple in passenger vehicles. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and upstream fuse, clamping surges before they reach PMIC or microcontroller power inputs. Use Value: Limits transient voltage to ≤26.9V during 400W ISO 7637-2 Pulse 1 events, preserving downstream 3.3V/5V regulator integrity. | Use Scenario: Safeguarding buck converter input stage in ADAS camera modules exposed to ignition noise and switching interference. IC Role / Device Role / Timing Role: Standoff protector on VIN pin of DC/DC controller IC, absorbing coupled transients from nearby high-current solenoids or motors. Use Value: Sub-1µA leakage at 15V VWM prevents quiescent current degradation; fast <1ps response avoids propagation of ringing into control loop. |
| Industrial SMPS Line Surge Suppression | LED Driver Input Protection |
Use Scenario: Front-end protection of 24V industrial switch-mode power supplies subjected to lightning-induced surges on AC mains or DC bus lines. IC Role / Device Role / Timing Role: Primary-level TVS across bulk capacitor input, shunting energy before it reaches bridge rectifier and PFC stage. Use Value: 400W peak power rating handles repetitive 10/1000µs surges per IEC 61000-4-5 Level 3; DO-214AC footprint enables compact layout near entry connector. | Use Scenario: Overvoltage safeguard for constant-current LED drivers in street lighting systems experiencing grid fluctuations and capacitor discharge spikes. IC Role / Device Role / Timing Role: Reverse-biased clamp on driver input terminals, activated only during abnormal line excursions exceeding 15V. Use Value: 26.9V clamping ensures MOSFET gate drivers and current-sense amplifiers remain within absolute maximum ratings during 100V+ transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ15A | Lower VBR range (16.7–18.5V vs. 16.7–20.4V); tighter tolerance; same VWM, VC, and PPPM | Preferred where tighter breakdown consistency is required across temperature and lot variation | Select SMAJ15A when statistical process control demands narrower VBR distribution in high-volume automotive production |
| SMBJ15CH | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; higher thermal mass; 600W PPPM rating | Better suited for higher-energy transients or applications requiring extended thermal endurance | Choose SMBJ15CH if board layout allows larger footprint and system-level surge testing exceeds 400W single-pulse limits |
Compared with SMAJ15A and SMBJ15CH, the SMAJ15CH offers optimal balance of AEC-Q101 compliance, DO-214AC space efficiency, and 400W surge capability-making it ideal for space-constrained automotive modules where consistent clamping and automated assembly are prioritized over ultra-tight VBR tolerance or extreme energy handling.
Availability
SMAJ15CH is available at Aetrix Electronics and suitable for automotive ECU design, industrial SMPS development, and LED driver manufacturing requiring stable component supply and full traceability.
Supply support for SMAJ15CH 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 since 1979.
The SMAJ series was developed specifically for AEC-Q101-compliant automotive transient suppression, targeting ISO 7637-2 Pulse 1/2a/3b immunity in engine control, body electronics, and infotainment systems.
FAQ
What does the 'CH' suffix indicate in SMAJ15CH?
The 'CH' suffix in SMAJ15CH denotes a unidirectional TVS diode with cathode-band polarity marking and AEC-Q101 qualification. Unlike bidirectional variants (e.g., SMAJ15CAH), SMAJ15CH is intended for single-polarity protection on positive-rail applications such as 12V automotive power lines. This configuration ensures precise clamping behavior and compatibility with standard reverse-biased placement in power supply front-ends.
Is SMAJ15CH suitable for ISO 7637-2 Pulse 1 compliance testing?
Yes, SMAJ15CH is explicitly rated to meet ISO 7637-2 Pulse 1 (inductive load dump) requirements. Its 400W peak pulse power rating under 10/1000µs waveform, 26.9V clamping voltage at 14.9A, and AEC-Q101 qualification confirm its suitability for protecting electronic control units against 12V system load-dump transients up to ±100V. System-level validation remains necessary, but SMAJ15CH satisfies all parametric prerequisites.
What is the maximum junction temperature rating for SMAJ15CH?
The maximum junction temperature (TJ max) for SMAJ15CH is +150°C, as specified in the Absolute Maximum Ratings table. This rating enables reliable operation in under-hood automotive environments and thermally dense industrial PCBs. Derating of peak pulse power begins above TA = 25°C per the published Pulse Derating Curve (Fig.2), ensuring safe thermal margin even at elevated ambient temperatures.
How does SMAJ15CH differ from SMAJ15AH?
SMAJ15CH has a broader breakdown voltage range (16.7–20.4V) compared to SMAJ15AH (16.7–18.5V), reflecting looser VBR tolerance. Both share identical VWM (15V), VC (26.9V), IPPM (14.9A), and packaging. SMAJ15CH is typically selected for cost-sensitive or less precision-critical applications, while SMAJ15AH suits designs requiring tighter VBR consistency across temperature and manufacturing lots.
Can SMAJ15CH be used in bidirectional signal line protection?
No, SMAJ15CH is a unidirectional TVS diode and must not be used for bidirectional signal line protection. Its asymmetrical I-V curve conducts only in reverse bias; forward conduction occurs at ~3.5V VF, which would disrupt signal integrity. For bidirectional protection, use SMAJ15CAH or SMAJ15ACH-devices explicitly designed with symmetrical clamping in both polarities and marked with 'CAH' or 'ACH' suffixes.
SMAJ15CH 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):
- 15V
- Voltage - Breakdown (Min):
- 16.7V
- Voltage - Clamping (Max) @ Ipp:
- 26.9V
- Current - Peak Pulse (10/1000µs):
- 14.9A
- 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)
SMAJ15CH FAQ
1.How can I place an order for SMAJ15CH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ15CH 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 SMAJ15CH reliable?
The price and inventory of SMAJ15CH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ15CH is usually 5 days.
3.What payment methods are accepted for SMAJ15CH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ15CH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ15CH?
SMAJ15CH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ15CH 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 SMAJ15CH?
For technical support, including SMAJ15CH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ15CH requirements.
6.How does Aetrix verify that SMAJ15CH is sourced from the original manufacturer or authorized distributors?
All SMAJ15CH 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 SMAJ15CH meets industry standards.
7.What is the process for return or replacement of SMAJ15CH?
All SMAJ15CH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ15CH, 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 SMAJ15CH part is unused and in its original packaging.
Return procedure for SMAJ15CH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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