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STMicroelectronics 1.5KE18A
- Part No.:
- 1.5KE18A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-201AA, DO-27, Axial
- Datasheet:
-
1.5KE18A.pdf
- Description:
- TVS DIODE 15.3VWM 32.5VC DO201
- Quantity:
- Payment:
- Shipping:
Inventory:3,056
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Product details
Overview
1.5KE18A from STMicroelectronics is a unidirectional transient voltage suppression (TVS) diode in DO-201 package, designed for high-energy surge protection in power supply inputs and signal lines. It features a 18 V breakdown voltage (VBR = 15.3–18.9 V), 25.2 V clamping voltage at 59.5 A (10/1000 µs), 1500 W peak pulse power, and operates up to 175 °C junction temperature - deployed in industrial AC/DC adapters and telecom line interfaces.
For engineers reviewing the 1.5KE18A datasheet, 1.5KE18A pinout, 1.5KE18A application, or 1.5KE18A equivalent, this page delivers verified electrical specs, DO-201 terminal mapping, IEC 61000-4-2/4-4 compliance data, thermal derating curves, and direct alternative comparisons for ESD and lightning surge hardening.
Technical Context
The 1.5KE18A uses planar junction silicon technology to achieve low dynamic resistance (RD = 0.106 Ω) and stable clamping under repetitive surges. Its unidirectional polarity enables precise anode-cathode placement in DC-biased rails, with leakage current ≤1 µA at 15.3 V and Tj = 25 °C.
Thermal performance is defined by junction-to-ambient thermal resistance (RθJA) dependent on PCB copper area, and maximum lead temperature of 260 °C for 10 s soldering. The device supports full IEC 61000-4-2 level 4 immunity (30 kV contact/air discharge) and IEC 61000-4-4 level 4 (4 kV).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 15.3 / 17.1 / 18.9 V at IBR = 1 mA - ensures reliable turn-on before downstream IC damage threshold |
| VCL @ IPP | 25.2 V at 59.5 A (10/1000 µs) - limits protected circuit voltage to safe operating range during surge |
| PPP | 1500 W (10/1000 µs) - sustains single high-energy transients without degradation |
| RD | 0.106 Ω - minimizes voltage overshoot during fast-rising surges (e.g., EFT) |
| Tj max | +175 °C - enables operation in enclosed industrial enclosures without forced cooling |
| IR max @ VRM | 1 µA at 15.3 V - prevents standby power loss in battery-backed systems |
Pinout & Package
1.5KE18A is housed in a DO-201 axial-leaded package with cathode band marking. Leads are matte tin-plated for solderability and RoHS compliance. Package dimensions: A = 8.5–9.5 mm length, B = 25.4 mm overall length, C = 4.8–5.3 mm body diameter, D = 0.96–1.06 mm lead diameter.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Current entry point in forward bias; connected to lower-potential side of protected line | Enables DC blocking in reverse-biased protection configuration; defines polarity-sensitive placement |
| Cathode (banded end) | Current exit point in forward bias; connected to ground or return path | Provides low-impedance shunt path during overvoltage; must be routed with minimal inductance to ground |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 level 4 immunity | 30 kV air/contact discharge - eliminates need for external ESD staging in front-end interfaces |
| Low dynamic resistance (RD) | 0.106 Ω - reduces clamping voltage rise during fast 8/20 µs surges (e.g., lightning-induced) |
| High Tj rating | 175 °C - maintains surge capability in thermally constrained environments (e.g., sealed power supplies) |
| Planar junction construction | Enables <1 µA leakage at VRM - critical for low-power IoT sensor nodes and battery management |
Applications
| Industrial AC/DC Power Supplies | Telecom Line Interface Protection |
|---|---|
|
Use Scenario: Surge protection on primary-side rectified DC bus feeding SMPS controller ICs. IC Role / Device Role: Unidirectional TVS clamp placed between rectifier output and bulk capacitor. Use Value: Limits voltage spikes from lightning-induced surges to ≤25.2 V, preventing MOSFET gate oxide rupture and UC384x controller latch-up. |
Use Scenario: Overvoltage protection on POTS line interface circuits in VoIP gateways. IC Role / Device Role: Primary surge suppressor on tip/ring lines before isolation transformer and SLIC. Use Value: Withstands 4 kV IEC 61000-4-4 bursts while maintaining <1 µA leakage, preserving line impedance matching and echo cancellation. |
| Automotive Body Control Modules | Industrial PLC Digital Input Cards |
|
Use Scenario: Protection of 12 V supply rail against load dump and ISO 7637-2 pulse 5a. IC Role / Device Role: Secondary clamp after upstream TVS array, absorbing residual energy post-filtering. Use Value: Delivers 1500 W peak power handling at Tj = 175 °C, enabling compact layout without heatsinking in confined BCM housings. |
Use Scenario: Field-side surge protection on 24 V digital input channels receiving signals from proximity sensors. IC Role / Device Role: First-line defense against induced transients from relay coil switching and motor noise. Use Value: Clamps 59.5 A surges to 25.2 V within 1 ns response time, preventing false triggering of optocoupler input stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18A (Diodes Inc.) | Same VBR range (15.3–18.9 V), but SMB package (smaller footprint); lower PPP = 600 W (10/1000 µs) | Preferred for space-constrained PCBs where surge energy ≤600 W suffices | Select when board real estate is critical and surge threat level is IEC 61000-4-4 level 2 (2 kV) |
| 1N6267A (ON Semiconductor) | Identical DO-201 package and 1500 W rating, but higher VCL = 27.7 V at 54.3 A and RD = 0.13 Ω | Less effective clamping margin for 3.3 V/5 V logic rails downstream | Choose only if legacy design compatibility requires ON's qualification history |
Compared with SMBJ18A and 1N6267A, the 1.5KE18A provides optimal balance of clamping voltage (25.2 V), dynamic resistance (0.106 Ω), and thermal robustness (175 °C) for industrial-grade 24 V system protection - making it preferred where surge energy exceeds 600 W and ambient temperatures exceed 85 °C.
Availability
1.5KE18A is available at Aetrix Electronics and suitable for industrial AC/DC power supplies, telecom line interfaces, and PLC digital input cards requiring stable component supply across extended temperature and surge stress conditions.
Supply support for 1.5KE18A 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, specializing in power management, analog, and protection devices for industrial, automotive, and consumer markets.
The 1.5KE series belongs to ST's high-power TVS portfolio, engineered specifically for robust front-end surge suppression in harsh electromagnetic environments - targeting reliability-critical infrastructure such as factory automation, energy metering, and base station power systems.
FAQ
What is the maximum clamping voltage of 1.5KE18A under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 25.2 V at 59.5 A for a 10/1000 µs waveform, measured at Tj = 25 °C. This value increases with junction temperature per αT = 8.8 × 10−4/°C, reaching ~27.5 V at Tj = 125 °C using the formula VCL(Tj) = VCL(25 °C) × [1 + αT × (Tj − 25)].
Can 1.5KE18A be used in bidirectional signal lines?
No - 1.5KE18A is unidirectional and must be installed with correct polarity (cathode to ground). For bidirectional protection, use the 1.5KE18CA variant, which has symmetrical breakdown in both directions and identical clamping characteristics for ± surges.
What is the recommended PCB layout practice for minimizing inductive voltage overshoot?
Route the cathode lead directly to a low-inductance ground plane using short, wide traces (<5 mm length, ≥2 mm width). Avoid vias in the clamping path; place the device within 10 mm of the protected node. Use thermal relief pads only on anode/cathode pads to maintain surge current integrity.
Does 1.5KE18A meet UL 497B for telecom surge protection?
Yes - it carries UL 497B file number QVGQ2.E136224, certifying compliance for primary protection in telecommunications equipment. This covers its use in POTS line interfaces, DSL modems, and VoIP gateways meeting ANSI/UL 497B Category A/B requirements.
1.5KE18A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-201AA, DO-27, Axial
- Series:
- 1.5KE, TRANSIL™
- Packaging:
- Cut Tape (CT)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 15.3V
- Voltage - Breakdown (Min):
- 17.6V
- Voltage - Clamping (Max) @ Ipp:
- 32.5V
- Current - Peak Pulse (10/1000µs):
- 308A (8/20µs)
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 4300pF @ 1MHz
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-201
1.5KE18A FAQ
1.How can I place an order for 1.5KE18A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1.5KE18A 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 1.5KE18A reliable?
The price and inventory of 1.5KE18A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1.5KE18A is usually 5 days.
3.What payment methods are accepted for 1.5KE18A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1.5KE18A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1.5KE18A?
1.5KE18A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1.5KE18A 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 1.5KE18A?
For technical support, including 1.5KE18A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1.5KE18A requirements.
6.How does Aetrix verify that 1.5KE18A is sourced from the original manufacturer or authorized distributors?
All 1.5KE18A 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 1.5KE18A meets industry standards.
7.What is the process for return or replacement of 1.5KE18A?
All 1.5KE18A units undergo pre-shipment inspection (PSI). If there is an issue with 1.5KE18A, 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 1.5KE18A part is unused and in its original packaging.
Return procedure for 1.5KE18A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1.5KE18A Tags
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