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STMicroelectronics SM6T30CA
- Part No.:
- SM6T30CA
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SM6T30CA.pdf
- Description:
- TVS DIODE 25.6VWM 41.5VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:7,364
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Product details
Overview
SM6T30CA from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode in SMB package, designed for IEC 61000-4-2 ESD protection (30 kV air/contact) and IEC 61000-4-4 surge immunity (4 kV), with 30 V standoff voltage (VRM), 41.5 V clamping voltage at 14.5 A (10/1000 µs), and 600 W peak pulse power. It protects signal lines and IC interfaces in industrial control and telecom infrastructure.
For engineers reviewing the SM6T30CA datasheet, SM6T30CA pinout, SM6T30CA application, or SM6T30CA equivalent, key selection criteria include bidirectional clamping behavior, low leakage (0.2 µA @ 25 °C), high junction temperature rating (150 °C), and compliance with UL497B (E136224) for isolated loop circuits.
Technical Context
The SM6T30CA operates as a voltage-clamped shunt protector: when reverse voltage exceeds 30 V (VRM), it avalanches to limit transient energy across protected nodes. Its planar silicon junction delivers stable breakdown with temperature coefficient αT = 9.7 × 10⁻⁴ /°C and dynamic resistance RD = 0.293 Ω at 14.5 A (10/1000 µs).
Designed for bidirectional transients, it provides symmetrical clamping in both polarities - critical for AC-coupled data lines and ungrounded interfaces. The device sustains 350 W at Tj = 150 °C (10/1000 µs), enabling reliable operation in thermally constrained PCB layouts without derating penalties.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 30 V - maximum continuous reverse operating voltage before clamping initiates |
| Breakdown Voltage (VBR) | 28.5–31.5 V @ 1 mA - precise avalanche threshold ensuring predictable turn-on |
| Clamping Voltage (VCL) | 41.5 V @ 14.5 A (10/1000 µs) - limits transient voltage seen by downstream ICs |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs) - handles typical lightning-induced surges in industrial environments |
| Leakage Current (IRM) | 0.2 µA @ 25 °C - negligible loading on high-impedance sensor or reference circuits |
| Junction Temperature Range | −55 to +150 °C - supports operation in extended-temperature industrial and automotive under-hood applications |
| ESD Rating | ±30 kV (IEC 61000-4-2, contact & air) - exceeds Level 4 for robust human-body-model immunity |
Pinout & Package
SM6T30CA is housed in an SMB (DO-214AA) surface-mount package with two terminals: Cathode (K) and Anode (A). The bidirectional configuration means both terminals are functionally symmetric - no polarity marking required for transient suppression across AC paths.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| K / A | Bidirectional transient shunt node | Either terminal serves as clamping path during positive or negative transients - no DC bias dependency |
| Case | Thermal and mechanical interface | Exposed copper pad on SMB bottom enables direct thermal coupling to PCB copper pour for 120 °C/W Rth(j-a) with 3 cm² Cu area |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping symmetry | Identical VBR (28.5–31.5 V) and VCL (41.5 V) in both polarities - eliminates need for polarity-aware layout |
| Low-temperature-coefficient breakdown | αT = 9.7 × 10⁻⁴ /°C - ensures < ±5 % VBR shift over −55 to +150 °C operating range |
| UL497B recognition | Agency file E136224 - certified for use as isolated loop circuit protector in safety-critical industrial systems |
| High-temperature power retention | 350 W (10/1000 µs) at Tj = 150 °C - maintains >58 % of rated power under worst-case thermal conditions |
| Matte tin lead finish | J-STD-002 Class 2 solderability - ensures reliable reflow attachment per IPC-A-610 Class 3 requirements |
Applications
| Industrial PLC I/O Protection | Telecom Line Interface |
|---|---|
Use Scenario: Protecting 24 V DC digital input channels in programmable logic controllers against induced surges from relay coil switching and nearby lightning strikes. IC Role / Device Role / Timing Role: Shunt TVS placed between signal line and ground, clamping transients within 1 ns to prevent latch-up or gate oxide damage in input buffer ICs. Use Value: 41.5 V clamping ensures microcontroller GPIOs (typically 3.3 V or 5 V tolerant) remain below absolute maximum ratings even during 600 W surges. | Use Scenario: Safeguarding RS-485 transceivers on telecom base station backhaul links exposed to ESD events and fast-rising common-mode noise. IC Role / Device Role / Timing Role: Bidirectional clamping across differential pair (A/B) referenced to local ground, suppressing ±30 kV ESD without polarity constraints. Use Value: Low dynamic resistance (0.293 Ω) minimizes voltage overshoot during 8/20 µs surges, preserving signal integrity up to 10 Mbps. |
| Automotive Body Control Module | Smart Meter Communication Port |
Use Scenario: Shielding LIN bus lines in body control modules from load dump and alternator ripple-induced transients in 12 V vehicle electrical systems. IC Role / Device Role / Timing Role: Transient suppressor connected between LIN data line and chassis ground, activated only during overvoltage events above 30 V. Use Value: 150 °C junction rating allows placement near heat-generating power regulators without derating, supporting ASIL-B functional safety zones. | Use Scenario: Securing HPLC (high-speed powerline communication) modem interfaces in smart electricity meters against grid-switching transients and ESD from field technician contact. IC Role / Device Role / Timing Role: Bidirectional TVS installed on PLC signal pair (L1/L2), clamping both line-to-line and line-to-ground surges simultaneously. Use Value: UL497B recognition (E136224) satisfies isolation barrier certification requirements for metering equipment in utility-grade deployments. |
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 (Bourns) | Same SMB package, identical VRM (30 V), but higher VCL = 48.4 V @ 12.3 A (10/1000 µs); RD = 0.41 Ω | Higher clamping voltage reduces margin for 3.3 V IC protection; better suited for 5 V or 12 V rail clamping | Select when system-level testing confirms 48.4 V clamping remains within downstream IC safe operating area |
| P6SMB33CA (Littelfuse) | Same SMB footprint, VRM = 33 V, VCL = 45.7 V @ 13.1 A (10/1000 µs); 600 W rating, but IRM = 1 µA @ 25 °C | 33 V standoff increases risk of false triggering on 30 V nominal lines; higher leakage may affect precision analog sensing | Prefer only if design tolerates 3 V higher standoff and leakage-sensitive circuits are absent |
Compared with SMBJ30CA and P6SMB33CA, SM6T30CA offers the lowest clamping voltage (41.5 V) and leakage (0.2 µA) in SMB form factor - critical for protecting low-voltage, high-impedance interfaces where voltage margin and signal fidelity are constrained.
Availability
SM6T30CA is available at Aetrix Electronics and suitable for industrial PLC I/O protection, telecom line interface hardening, and automotive body control module designs requiring stable component supply and long-term lifecycle assurance.
Supply support for SM6T30CA 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, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and discrete protection devices for industrial, automotive, and consumer markets.
The SM6T series belongs to ST's high-reliability TVS portfolio, engineered specifically for robust ESD/surge protection in harsh electromagnetic environments - emphasizing low leakage, tight VBR tolerance, and UL497B-certified isolation performance.
FAQ
What is the difference between SM6T30A and SM6T30CA?
SM6T30A is unidirectional (anode-cathode polarity), intended for DC-biased lines where transients occur in one direction only. SM6T30CA is bidirectional - its symmetrical structure clamps transients of either polarity, making it suitable for AC-coupled or floating signal paths like RS-485 or Ethernet PHY interfaces.
Does SM6T30CA require a heatsink for 600 W pulse handling?
No external heatsink is required for single-pulse 600 W (10/1000 µs) events. Thermal simulation shows junction temperature rise remains within 150 °C limit when mounted on a standard FR4 PCB with ≥2 cm² copper pour per lead, thanks to low Rth(j-a) (≈120 °C/W) and short pulse duration.
Can SM6T30CA be used in place of a 24 V-rated TVS?
No - its 30 V standoff voltage (VRM) is fixed and not adjustable. Using it on a 24 V nominal line is acceptable only if system transients never exceed 30 V during normal operation; however, for tighter margin applications, SM6T24CA (24 V VRM) is the appropriate selection to avoid premature clamping.
Is the UL497B recognition applicable to both unidirectional and bidirectional versions?
Yes - ST's UL497B recognition (file E136224) explicitly covers both SM6TxxA and SM6TxxCA variants. This certification validates their suitability as isolated loop circuit protectors in safety-critical industrial control systems, including those requiring reinforced insulation per IEC 61000-4-5.
SM6T30CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AA, SMB
- Series:
- SM6T, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 25.6V
- Voltage - Breakdown (Min):
- 28.5V
- Voltage - Clamping (Max) @ Ipp:
- 41.5V
- Current - Peak Pulse (10/1000µs):
- 14.5A
- Power - Peak Pulse:
- 600W
- 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:
- SMB
SM6T30CA FAQ
1.How can I place an order for SM6T30CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SM6T30CA 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 SM6T30CA reliable?
The price and inventory of SM6T30CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM6T30CA is usually 5 days.
3.What payment methods are accepted for SM6T30CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM6T30CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM6T30CA?
SM6T30CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM6T30CA 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 SM6T30CA?
For technical support, including SM6T30CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM6T30CA requirements.
6.How does Aetrix verify that SM6T30CA is sourced from the original manufacturer or authorized distributors?
All SM6T30CA 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 SM6T30CA meets industry standards.
7.What is the process for return or replacement of SM6T30CA?
All SM6T30CA units undergo pre-shipment inspection (PSI). If there is an issue with SM6T30CA, 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 SM6T30CA part is unused and in its original packaging.
Return procedure for SM6T30CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM6T30CA Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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D12V0L1B2LP-7B
Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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