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STMicroelectronics SMTPA240
- Part No.:
- SMTPA240
- Manufacturer:
- STMicroelectronics
- Category:
- Thyristors
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMTPA240.pdf
- Description:
- THYRISTOR 240V 150A DO-214AA
- Quantity:
- Payment:
- Shipping:
Inventory:5,518
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Product details
Overview
SMTPA240 from STMicroelectronics is a bidirectional Trisil™ surge protection device designed for telecom line interface circuits, featuring 240 V stand-off voltage (VRM), 320 V breakover voltage (VBO), 50 A repetitive peak pulse current (10/1000 µs), 12 mA minimum holding current (IH), and 25 pF capacitance at 50 V. It safeguards analog/digital xDSL/T1/E1 line cards against lightning-induced transients.
For engineers reviewing the SMTPA240 datasheet, SMTPA240 pinout, SMTPA240 application, or SMTPA240 equivalent, key selection criteria include its fail-safe short-circuit behavior under overvoltage, UL497B/UL1459/FCC Part 68 compliance, low leakage (<2 µA), and SMB (DO-214AA) surface-mount package suitability for high-density telecom PCB layouts.
Technical Context
The SMTPA240 operates as a voltage-triggered crowbar device: it remains high-impedance below 240 V, then switches to low-impedance conduction above 320 V to shunt surge energy. Its bidirectional symmetry enables protection on AC-coupled telecom lines without polarity concerns.
Thermal design relies on DO-214AA package characteristics-junction-to-ambient thermal resistance of 120 °C/W (with recommended footprint) and junction-to-leads of 30 °C/W-enabling reliable operation up to 150 °C junction temperature during transient events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 240 V - Maximum continuous operating voltage before triggering; defines safe AC/DC line interface rating. |
| Breakover Voltage (VBO) | 320 V - Voltage threshold at which device switches to low-impedance state; ensures robust margin above VRM. |
| Repetitive Peak Pulse Current | 50 A (10/1000 µs) - Sustains repeated lightning surges per GR-1089 Core Level 1 without degradation. |
| Holding Current (IH) | 12 mA min - Minimum current required to maintain conduction after triggering; ensures reliable latching during surge decay. |
| Capacitance (C) | 25 pF @ 50 V - Low signal distortion on high-speed telecom lines (e.g., xDSL up to 30 MHz). |
| Leakage Current (IRM) | 2 µA max @ 240 V - Negligible DC loading on protected line; preserves signal integrity in low-power analog interfaces. |
| Package | SMB (DO-214AA) - JEDEC-standardized surface-mount outline with 5.1–5.6 mm body width; compatible with automated assembly. |
Pinout & Package
SMB (DO-214AA) package: cathode-anode symmetrical bidirectional terminals; no polarity marking required; leads rated for 260 °C soldering (10 s).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Surge current entry (positive half-cycle) | Conducts during positive overvoltage; forms symmetrical path with cathode for bidirectional clamping. |
| Cathode (K) | Surge current entry (negative half-cycle) | Conducts during negative overvoltage; enables single-device protection of AC-coupled telecom lines. |
Key Features
| Feature | Design Value |
|---|---|
| Fail-safe short-circuit mode | Guarantees circuit interruption via permanent low-resistance state upon end-of-life, preventing open-circuit failure modes. |
| UL497B certification (E136224) | Validates compliance with telecom surge protection requirements for FCC Part 68 Type A/B lightning tests. |
| UL94 V0 epoxy encapsulation | Prevents flame propagation during fault conditions; meets safety standards for enclosed telecom equipment. |
| No aging degradation | Maintains consistent VBO and IH over >10⁵ surge cycles; eliminates recalibration or replacement schedules. |
Applications
| Analog Line Cards (xDSL) | Digital T1/E1 Interfaces |
|---|---|
Use Scenario: Protects ADSL/VDSL line drivers and receivers from induced surges on twisted-pair copper loops. IC Role / Device Role / Timing Role: Bidirectional crowbar clamping element placed between line transformer secondary and PHY IC input. Use Value: 25 pF capacitance avoids signal attenuation above 10 MHz; 320 V VBO withstands 2.5 kV GR-1089 surges with 20 Ω series impedance. | Use Scenario: Shields T1/E1 framer and line interface units (LIUs) in central office and CPE equipment. IC Role / Device Role / Timing Role: Primary overvoltage protector on balanced 100 Ω differential pairs carrying 1.544/2.048 Mbps data. Use Value: 50 A (10/1000 µs) rating meets GR-1089 Core Level 1; SMB package fits dense backplane card layouts. |
| ISDN Terminal Equipment | Fax/Modem Analog Ports |
Use Scenario: Secures BRI U-interface termination in NT1 devices against lightning coupling from PSTN lines. IC Role / Device Role / Timing Role: Standoff protector across tip/ring pair upstream of hybrid circuit and codec. Use Value: 240 V VRM matches ISDN loop voltage; fail-safe mode prevents service outage during device wear-out. | Use Scenario: Guards POTS-line-connected fax machines and dial-up modems against induced transients. IC Role / Device Role / Timing Role: First-stage protector on RJ11 interface, preceding transient voltage suppressor diodes. Use Value: UL1459/CSA C22.2 compliance ensures regulatory acceptance; 2 µA leakage avoids false off-hook detection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional telecom surge protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPA240 | DO-15 through-hole package; higher thermal resistance (100 °C/W j-a); identical electrical specs. | Preferred for prototyping or legacy through-hole designs; less suitable for high-density SMT production. | Select when manual assembly or board-level repairability is prioritized over automated manufacturing efficiency. |
| SMTPA220 | Lower VRM (220 V) and VBO (293 V); same SMB package and 50 A rating. | Better suited for 176 VAC nominal systems (e.g., European POTS) where 240 V margin is excessive. | Choose for cost-sensitive deployments where reduced voltage margin aligns with local grid specifications. |
Compared with TPA240 and SMTPA220, SMTPA240 provides optimal balance of high-voltage margin (240 V VRM), SMT manufacturability (SMB), and telecom-specific certifications-making it the default choice for new xDSL/T1/E1 designs targeting global deployment.
Availability
SMTPA240 is available at Aetrix Electronics and suitable for analog line cards (xDSL), digital T1/E1 interfaces, ISDN terminal equipment, and fax/modem analog ports requiring stable component supply across multi-year telecom infrastructure programs.
Supply support for SMTPA240 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 silicon solutions for automotive, industrial, and communications markets since 1987.
The Trisil™ product line was engineered specifically for fail-safe, high-reliability surge protection in telecom infrastructure-addressing GR-1089, ITU-T K.20/K.21, and FCC Part 68 compliance requirements in central office and customer premises equipment.
FAQ
What is the maximum continuous operating voltage for SMTPA240?
The SMTPA240 has a stand-off voltage (VRM) of 240 V, meaning it can continuously block up to 240 V DC or RMS AC without triggering. This rating is validated per IEC61000-4-5 and FCC Part 68, ensuring compatibility with standard telecom line voltages including 176 VAC (Europe) and -48 VDC (North American central office).
Does SMTPA240 require a series current-limiting resistor?
Yes-SMTPA240 requires an external series resistor to limit follow current after triggering. For GR-1089 Core Level 1 (2500 V, 10/1000 µs), a minimum 20 Ω resistor is specified; for FCC Part 68 Type A (1500 V, 10/160 µs), 12.5 Ω is required. Resistor value is determined by system voltage, fault current, and required let-through energy.
How does SMTPA240 behave after a surge event?
After conducting a surge, SMTPA240 remains latched in low-impedance state until line current falls below its 12 mA minimum holding current (IH). In normal operation, this occurs naturally during AC zero-crossings or DC power removal. If sustained overcurrent persists, it enters fail-safe short-circuit mode-protecting downstream circuitry while signaling end-of-life.
Is SMTPA240 compliant with RoHS and REACH regulations?
Yes-SMTPA240 is supplied in ECOPACK®-compliant SMB packages with lead-free second-level interconnects, meeting EU RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. The inner box label specifies lead-free status per JEDEC JESD97, and soldering profiles comply with IPC/JEDEC J-STD-020.
SMTPA240 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AA, SMB
- Series:
- SMP, TRISIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Breakover:
- 320V
- Voltage - Off State:
- 240V
- Voltage - On State:
- -
- Current - Peak Pulse (8/20µs):
- 150 A
- Current - Peak Pulse (10/1000µs):
- 50 A
- Current - Hold (Ih):
- 150 mA
- Number of Elements:
- 1
- Capacitance:
- 25pF
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
SMTPA240 FAQ
1.How can I place an order for SMTPA240 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMTPA240 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 SMTPA240 reliable?
The price and inventory of SMTPA240 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMTPA240 is usually 5 days.
3.What payment methods are accepted for SMTPA240?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMTPA240 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMTPA240?
SMTPA240 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMTPA240 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 SMTPA240?
For technical support, including SMTPA240 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMTPA240 requirements.
6.How does Aetrix verify that SMTPA240 is sourced from the original manufacturer or authorized distributors?
All SMTPA240 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 SMTPA240 meets industry standards.
7.What is the process for return or replacement of SMTPA240?
All SMTPA240 units undergo pre-shipment inspection (PSI). If there is an issue with SMTPA240, 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 SMTPA240 part is unused and in its original packaging.
Return procedure for SMTPA240:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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