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Taiwan Semiconductor Corporation 1KSMB18CAH
- Part No.:
- 1KSMB18CAH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1KSMB18CAH.pdf
- Description:
- TVS DIODE 15.3VWM 25.5VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:5,644
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Product details
Overview
1KSMB18CAH from Taiwan Semiconductor is a bi-directional 1000W transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, with breakdown voltage 17.1–18.9 V at 1 mA, clamping voltage 25.5 V at 39.2 A peak pulse current, and AEC-Q101 qualification for automotive-grade surge protection in power supply and signal line interfaces.
For engineers reviewing the 1KSMB18CAH datasheet, 1KSMB18CAH pinout, 1KSMB18CAH application, or 1KSMB18CAH equivalent, this page delivers verified electrical parameters, bi-directional TVS behavior, ISO 7637-2 compliance, thermal resistance data, and real-world ESD/inductive load protection use cases - all confirmed from Taiwan Semiconductor's official A2102 specification document.
Technical Context
The 1KSMB18CAH is a bi-directional silicon avalanche diode designed to clamp transient overvoltages in both polarities without requiring external polarity management. Its glass-passivated junction ensures stable breakdown and low leakage, while sub-1 ps response time enables protection against fast EFT and ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
Thermally, it features RθJL = 20°C/W and RθJA = 100°C/W, supporting sustained operation up to TJ = 175°C. Its 1000 W peak pulse power rating (10/1000 µs waveform) and 25.5 V clamping voltage at 39.2 A define its robustness in automotive and industrial DC bus protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/max) | 17.1 V / 18.9 V @ IT = 1 mA - defines reliable avalanche initiation threshold under bidirectional stress |
| VWM | 15.3 V - maximum continuous reverse operating voltage before leakage exceeds 1 µA |
| VC @ IPP | 25.5 V @ 39.2 A - clamped voltage during 10/1000 µs surge, limiting downstream IC stress |
| PPPSM | 1000 W - peak pulse power handling capability per standard 10/1000 µs waveform |
| IPP | 39.2 A - maximum non-repetitive surge current the device safely clamps without failure |
| TJ max | 175°C - maximum junction temperature enabling under-hood automotive deployment |
| Configuration | Bi-directional single-die - eliminates need for dual unidirectional devices in AC or floating DC lines |
Pinout & Package
Package: DO-214AA (SMB), surface-mount, matte tin-plated leads, polarity indicated by cathode band (not applicable for bi-directional 1KSMB18CAH; symmetric terminal function).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bidirectional avalanche junction terminals | Either terminal accepts positive or negative transients - no polarity assignment required in layout |
| Case (body) | Non-electrical mechanical interface | DO-214AA outline provides standardized solder pad footprint and thermal path to PCB copper |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics per stress test requirements including temperature cycling, HTRB, and ESD |
| Glass passivated junction | Ensures stable VBR tolerance and low long-term parameter drift under thermal/humidity stress |
| ISO 7637-2 compliance | Meets Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (EFT) immunity standards |
| Moisture sensitivity level 1 | Zero bake requirement prior to reflow - compatible with standard SMT assembly processes |
| RoHS & halogen-free | Complies with IEC 61249-2-21 and EU RoHS directives for environmentally constrained applications |
Applications
| Automotive Power Line Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs from load dump and alternator transients per ISO 7637-2 Pulse 1 and Pulse 2b. IC Role / Device Role / Timing Role: Bidirectional clamping element placed across power rail and ground, absorbing >1000 W surges within nanoseconds. Use Value: Limits rail voltage to ≤25.5 V during 39.2 A transients, preventing damage to MCU, CAN transceivers, and analog front-ends. | Use Scenario: Safeguarding 4–20 mA current loop inputs and RS-485 transceivers against ESD and cable-induced surges in factory automation. IC Role / Device Role / Timing Role: Bi-directional TVS placed differential-mode across signal pair and common-mode to ground. Use Value: Clamps ±25.5 V transients without polarity biasing, preserving signal integrity while meeting IEC 61000-4-2 Level 4 (15 kV air/8 kV contact). |
| LED Driver Output Protection | DC Motor Control Board Protection |
Use Scenario: Shielding constant-current LED driver outputs from inductive kickback when driving high-side MOSFETs or solenoids. IC Role / Device Role / Timing Role: Parallel-connected TVS across output terminals to clamp flyback spikes during switch-off. Use Value: Suppresses >100 V inductive spikes to ≤25.5 V within <1 ps, eliminating need for snubbers and reducing board space. | Use Scenario: Protecting H-bridge gate drivers and current sense amplifiers from back-EMF during motor commutation and stall events. IC Role / Device Role / Timing Role: Mounted across motor terminals and/or between each half-bridge leg and ground. Use Value: Handles repetitive 39.2 A pulses with 175°C junction rating, enabling reliable operation in enclosed motor control enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18CA (ON Semiconductor) | Same DO-214AA package; VBR = 19.0–21.0 V, VC = 29.2 V @ 34.2 A - higher clamping voltage, lower peak current | Less effective clamping margin for 12 V systems near 25 V absolute max ratings | Select when legacy ON Semi BOM alignment is required and 29.2 V clamping is acceptable |
| P6SMB18CA (Littelfuse) | VBR = 19.0–21.0 V, VC = 29.2 V @ 34.2 A, same 1000 W rating - identical electrical envelope but different thermal derating curve | Slightly reduced surge current margin in high-ambient environments due to higher RθJA | Prefer for Littelfuse-design ecosystems where P6SMB series is already qualified |
Compared with SMBJ18CA and P6SMB18CA, the 1KSMB18CAH offers tighter VBR (17.1–18.9 V) and lower clamping (25.5 V), delivering superior voltage margin for 12 V automotive and industrial rails - critical where downstream ICs have narrow absolute maximum ratings.
Availability
1KSMB18CAH is available at Aetrix Electronics and suitable for automotive power line protection, industrial sensor interface hardening, LED driver output safeguarding, and DC motor control board surge suppression requiring stable component supply and AEC-Q101-compliant sourcing.
Supply support for 1KSMB18CAH 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs, with global distribution and AEC-Q101 qualification capabilities.
The 1KSMBxxCAH series is part of TSC's automotive-grade TVS portfolio, engineered specifically for ISO 7637-2-compliant transient suppression in 12 V/24 V vehicle subsystems and harsh industrial environments.
FAQ
What does the 'CAH' suffix indicate in 1KSMB18CAH?
The 'CAH' suffix denotes a bi-directional configuration - meaning the 1KSMB18CAH functions identically under both positive and negative transient polarity, unlike unidirectional 'AH' variants. This eliminates the need for polarity-aware placement and simplifies design for AC-coupled or floating DC circuits. The device achieves this via symmetrical avalanche junction construction, confirmed in TSC's A2102 datasheet Section "Devices for Bipolar Applications".
Is 1KSMB18CAH suitable for 12 V automotive power rail protection?
Yes, the 1KSMB18CAH is explicitly validated for 12 V automotive use: its 15.3 V stand-off voltage (VWM) accommodates normal battery fluctuations (up to ~14.8 V), while its 25.5 V clamping voltage stays well below typical 36 V absolute maximum ratings of automotive MCUs and transceivers. It meets ISO 7637-2 Pulse 1 (load dump) and Pulse 2b (inductive switching), per TSC A2102 documentation.
How does the thermal performance of 1KSMB18CAH affect PCB layout?
The 1KSMB18CAH has RθJL = 20°C/W and RθJA = 100°C/W, meaning effective heat dissipation relies on adequate copper area connected to its leads. For repeated surge events, designers should use ≥100 mm² of 1 oz. copper per lead and avoid thermal isolation. The DO-214AA footprint supports this via exposed metal pads - confirmed in TSC's Package Outline Dimensions (Page 6, A2102).
Does 1KSMB18CAH require special handling during reflow soldering?
No special handling is needed: the 1KSMB18CAH is rated Moisture Sensitivity Level 1 (per J-STD-020), meaning it can be stored indefinitely at ambient conditions and placed directly into standard lead-free reflow profiles without baking. Its matte tin-plated leads ensure solderability per J-STD-002, and the UL 94V-0 molding compound withstands peak temperatures up to 260°C.
What is the maximum repetitive surge capability of 1KSMB18CAH?
The 1KSMB18CAH is rated for non-repetitive 10/1000 µs pulses per Fig. 2 (Pulse Derating Curve) in the A2102 datasheet. Repetitive operation is not specified - it must be thermally derated based on duty cycle and ambient temperature. For designs requiring frequent surges, thermal modeling using RθJA = 100°C/W and TJ ≤ 175°C is required; TSC does not publish safe repetition rate limits for this device.
1KSMB18CAH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- 1KSMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 15.3V
- Voltage - Breakdown (Min):
- 17.1V
- Voltage - Clamping (Max) @ Ipp:
- 25.5V
- Current - Peak Pulse (10/1000µs):
- 39.2A
- Power - Peak Pulse:
- 1000W (1kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
1KSMB18CAH FAQ
1.How can I place an order for 1KSMB18CAH through Aetrix?
Please submit a Request for Quotation (RFQ) for 1KSMB18CAH 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 1KSMB18CAH reliable?
The price and inventory of 1KSMB18CAH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1KSMB18CAH is usually 5 days.
3.What payment methods are accepted for 1KSMB18CAH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1KSMB18CAH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1KSMB18CAH?
1KSMB18CAH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1KSMB18CAH 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 1KSMB18CAH?
For technical support, including 1KSMB18CAH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1KSMB18CAH requirements.
6.How does Aetrix verify that 1KSMB18CAH is sourced from the original manufacturer or authorized distributors?
All 1KSMB18CAH 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 1KSMB18CAH meets industry standards.
7.What is the process for return or replacement of 1KSMB18CAH?
All 1KSMB18CAH units undergo pre-shipment inspection (PSI). If there is an issue with 1KSMB18CAH, 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 1KSMB18CAH part is unused and in its original packaging.
Return procedure for 1KSMB18CAH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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