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STMicroelectronics SMAJ30CA-TR
- Part No.:
- SMAJ30CA-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ30CA-TR.pdf
- Description:
- TVS DIODE 30VWM 64.3VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:70,124
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Product details
Overview
SMAJ30CA-TR from STMicroelectronics is a bidirectional 30 V standoff transient voltage suppression (TVS) diode in SMA package, rated for 400 W peak pulse power (10/1000 µs), 64.3 A peak pulse current, and clamping voltage of 48.4 V at 8.3 A. It protects Ethernet PHY interfaces, USB 2.0 data lines, and industrial I/O ports against IEC 61000-4-2 ESD (±30 kV contact/air) and IEC 61000-4-4 EFT (4 kV).
For engineers reviewing the SMAJ30CA-TR datasheet, SMAJ30CA-TR pinout, SMAJ30CA-TR application, or SMAJ30CA-TR equivalent, this page delivers verified electrical parameters, JEDEC DO-214AC package details, bidirectional surge response behavior, thermal derating curves, and direct alternatives with clamping voltage and leakage trade-offs.
Technical Context
This bidirectional TVS diode operates symmetrically across both polarities, with breakdown voltage (VBR) specified at 33.3–35.1 V (IBR = 1 mA) and dynamic resistance (RD) of 0.762 Ω at 8/20 µs pulse. Its low leakage (0.2 µA @ 25 °C, 1 µA @ 85 °C) supports high-impedance signal paths in sensor front-ends and isolated communication lines.
The device complies with J-STD-020 MSL Level 1, IPC7531 footprint, and JEDEC DO-214AC outline. Junction temperature range spans –55 to +150 °C, enabling deployment in automotive body control modules and outdoor industrial gateways where ambient thermal cycling exceeds 100 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRWM) | 30 V - Maximum continuous reverse working voltage before breakdown; sets minimum system operating margin for 24 V DC rails. |
| Breakdown Voltage (VBR) | 33.3–35.1 V @ 1 mA - Confirmed threshold where avalanche conduction begins; defines ESD immunity trigger point. |
| Clamping Voltage (VCL) | 48.4 V @ 8.3 A (10/1000 µs) - Peak voltage seen by protected circuit during surge; determines safe overvoltage headroom for 3.3 V/5 V logic. |
| Peak Pulse Power (PPP) | 400 W @ Tj = 25 °C (10/1000 µs) - Sustained surge energy handling; derates to ~250 W at 125 °C junction per Figure 3. |
| Leakage Current (IR) | 0.2 µA @ 25 °C, 1 µA @ 85 °C - Enables use in battery-powered IoT sensor nodes without measurable standby drain. |
| ESD Rating | ±30 kV contact & air discharge (IEC 61000-4-2 Level 4) - Meets highest industrial ESD immunity requirement without external shielding. |
Pinout & Package
Package: SMA (JEDEC DO-214AC), surface-mount, single-row two-terminal configuration with matte tin-plated leads compliant with J-STD-002 and JESD 22-B102 E3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Cathode Mark Side) | Surge return path (bidirectional) | Terminal connected to GND or reference plane; symmetrical conduction enables protection on AC-coupled or floating lines. |
| Cathode (Marked Band) | Surge return path (bidirectional) | Identical function to Anode; no polarity dependency-both terminals behave identically under positive/negative transients. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional surge suppression | Enables single-device protection of differential buses (e.g., RS-485, CAN FD) without polarity constraints or external biasing. |
| Low dynamic resistance (0.762 Ω) | Minimizes clamping voltage overshoot during fast 8/20 µs surges, preserving timing integrity in high-speed digital interfaces. |
| Junction temperature rating (150 °C) | Supports operation in engine-control units and motor drives where PCB local heating exceeds 125 °C ambient. |
| UL94 V0 flammability rating | Meets safety-critical enclosure requirements for medical and industrial equipment without additional potting or flame-retardant board material. |
Applications
| Industrial PLC Analog Input | Automotive Body Control Module |
|---|---|
Use Scenario: Protects 4–20 mA current-loop inputs from induced surges on factory floor wiring. IC Role / Device Role / Timing Role: Bidirectional clamping element placed between input terminal and ADC front-end, shunting transients before op-amp input stage. Use Value: 48.4 V clamping ensures downstream instrumentation amplifier (e.g., AD8420) remains within absolute maximum ratings during 4 kV EFT bursts. | Use Scenario: Shields LIN bus transceiver pins from load-dump and jump-start induced spikes in door module ECUs. IC Role / Device Role / Timing Role: Standoff-limited TVS placed directly at connector entry point, absorbing >95% of 100 V/50 ms load dump energy before reaching transceiver. Use Value: 0.2 µA leakage prevents false wake-up in sleep mode; 150 °C Tj rating sustains reliability near HVAC actuators. |
| USB 2.0 Data Line Protection | Smart Meter RS-485 Interface |
Use Scenario: Safeguards D+ and D− lines against ESD events during hot-plug insertion in consumer electronics. IC Role / Device Role / Timing Role: Low-capacitance bidirectional TVS (CJ ≈ 120 pF @ 0 V) placed adjacent to USB connector, minimizing signal rise-time degradation. Use Value: ±30 kV ESD rating eliminates need for secondary ESD protection ICs; 48.4 V clamping avoids violating USB 2.0 eye diagram mask. | Use Scenario: Guards half-duplex RS-485 transceivers (e.g., SN65HVD72) against lightning-induced surges on utility meter communication lines. IC Role / Device Role / Timing Role: Primary surge suppressor mounted at PCB edge connector, clamping common-mode transients before differential receiver input. Use Value: 400 W 10/1000 µs rating handles typical 100 A lightning surge currents; bidirectional symmetry matches RS-485 differential signaling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ30CA-TR | Same VRWM/VBR, but 600 W PPP (10/1000 µs), higher VCL = 49.9 V @ 12.1 A, SMB package (DO-214AA) | Higher surge margin for outdoor telecom cabinets; larger footprint limits dense PCB layouts. | Select when surge energy exceeds 400 W but board space permits SMB size. |
| SMCJ30CA-TR | Same VRWM/VBR, 1500 W PPP (10/1000 µs), VCL = 49.3 V @ 30.4 A, SMC package (DO-214AB) | Required for primary-level protection in solar inverters or EV charging stations with multi-kV surge exposure. | Choose only when system-level testing confirms >600 W surge threat; avoid for signal-line protection due to higher capacitance. |
Compared with SMBJ30CA-TR and SMCJ30CA-TR, SMAJ30CA-TR provides optimal balance of compact DO-214AC footprint, 400 W surge capability, and sub-1 µA leakage-making it preferred for space-constrained, low-power industrial and automotive signal protection where 600 W+ margins are unnecessary.
Availability
SMAJ30CA-TR is available at Aetrix Electronics and suitable for industrial PLC analog inputs, automotive body control modules, USB 2.0 data line protection, and smart meter RS-485 interfaces requiring stable component supply across production lifecycles.
Supply support for SMAJ30CA-TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, power devices, sensors, and protection components for industrial, automotive, and consumer markets.
The SMAJ series belongs to ST's transient protection portfolio, engineered specifically for robust, low-leakage, bidirectional ESD and surge suppression in high-reliability signal-path applications where thermal stability and JEDEC-compliant packaging are mandatory.
FAQ
What is the maximum clamping voltage of SMAJ30CA-TR under a 10/1000 µs surge?
The maximum clamping voltage is 48.4 V at 8.3 A for a 10/1000 µs waveform, measured at Tj = 25 °C. This value increases with junction temperature per the αT coefficient (9.9 × 10−4/°C), reaching ~52.1 V at 125 °C per Equation 3 in DS1251 Rev 15.
Is SMAJ30CA-TR unidirectional or bidirectional?
SMAJ30CA-TR is a bidirectional TVS diode, indicated by the "CA" suffix. It conducts symmetrically for both positive and negative transients, making it suitable for protecting AC-coupled or floating differential lines like RS-485, CAN, or Ethernet PHYs without polarity concerns.
Does SMAJ30CA-TR meet automotive AEC-Q200 stress test requirements?
No-SMAJ30CA-TR is not AEC-Q200 qualified. While it operates up to 150 °C junction temperature and meets JESD22-A108 temperature cycling, it lacks the full qualification test suite (e.g., board-level vibration, humidity bias) required for automotive-grade components. For AEC-Q200 applications, consider ST's Automotive Qualified SMAJ variants (e.g., SMAJ30CAQTR).
How does the SMA package compare to SMB and SMC in terms of thermal performance?
The SMA (DO-214AC) package has higher thermal resistance than SMB (DO-214AA) and SMC (DO-214AB): Rth(j-a) ≈ 120 °C/W on standard FR4 (vs. ~90 °C/W for SMB and ~60 °C/W for SMC). This limits sustained power dissipation but remains sufficient for transient-only events; layout with 1 cm² copper per pad reduces Rth(j-a) to ~45 °C/W per Figure 12.
SMAJ30CA-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 30V
- Voltage - Breakdown (Min):
- 33.3V
- Voltage - Clamping (Max) @ Ipp:
- 64.3V
- Current - Peak Pulse (10/1000µs):
- 36A (8/20µs)
- 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)
SMAJ30CA-TR FAQ
1.How can I place an order for SMAJ30CA-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ30CA-TR 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 SMAJ30CA-TR reliable?
The price and inventory of SMAJ30CA-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ30CA-TR is usually 5 days.
3.What payment methods are accepted for SMAJ30CA-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ30CA-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ30CA-TR?
SMAJ30CA-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ30CA-TR 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 SMAJ30CA-TR?
For technical support, including SMAJ30CA-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ30CA-TR requirements.
6.How does Aetrix verify that SMAJ30CA-TR is sourced from the original manufacturer or authorized distributors?
All SMAJ30CA-TR 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 SMAJ30CA-TR meets industry standards.
7.What is the process for return or replacement of SMAJ30CA-TR?
All SMAJ30CA-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ30CA-TR, 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 SMAJ30CA-TR part is unused and in its original packaging.
Return procedure for SMAJ30CA-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ30CA-TR Tags
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