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Taiwan Semiconductor Corporation 1KSMB33A
- Part No.:
- 1KSMB33A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1KSMB33A.pdf
- Description:
- TVS DIODE 28.2VWM 45.7VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:8,283
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Product details
Overview
1KSMB33A from Taiwan Semiconductor is a unidirectional 1000W transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, with breakdown voltage 31.4–34.7 V at 1 mA, stand-off voltage 28.2 V, clamping voltage 45.7 V at 21.9 A, and junction temperature range −55 °C to +175 °C. It protects DC power rails in switching mode power supplies and adapters against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the 1KSMB33A datasheet, 1KSMB33A pinout, 1KSMB33A application, or 1KSMB33A equivalent, key selection criteria include unidirectional polarity, 28.2 V working voltage, 45.7 V max clamping under 21.9 A 10/1000 µs surge, DO-214AA thermal resistance (RθJL = 20 °C/W), and compliance with J-STD-020 moisture level 1 and RoHS/halogen-free requirements.
Technical Context
The 1KSMB33A operates as a silicon avalanche diode, triggered when reverse voltage exceeds its 31.4–34.7 V breakdown threshold, diverting surge current away from protected circuitry. Its glass-passivated junction ensures stable VBR and low leakage (<1 µA @ 28.2 V).
Designed for automotive and industrial DC input protection, it meets ISO 7637-2 immunity requirements for load dump and inductive switching transients. Thermal performance is defined by RθJL = 20 °C/W and RθJA = 100 °C/W, enabling reliable operation up to 175 °C junction temperature under pulsed conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28.2 V - maximum continuous reverse operating voltage before leakage exceeds 1 µA |
| VBR @ IT=1 mA | 31.4–34.7 V - verified avalanche conduction onset, ensuring predictable turn-on during transients |
| VC @ IPP=21.9 A | 45.7 V - peak clamped voltage during 10/1000 µs surge, limiting downstream voltage stress |
| PPPSM | 1000 W - non-repetitive peak pulse power handling per standard waveform, defining surge robustness |
| IPP | 21.9 A - maximum peak impulse current supported at rated clamping voltage |
| Junction Temp Range | −55 °C to +175 °C - enables deployment in under-hood automotive and industrial environments |
| RθJL | 20 °C/W - low junction-to-lead thermal resistance supports efficient heat transfer to PCB copper |
Pinout & Package
Package: DO-214AA (SMB), surface-mount, matte tin-plated leads, polarity indicated by cathode band. Weight: 0.110 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Surge return path | Connected to ground or low-impedance return in unidirectional TVS configuration |
| Cathode | Protected line connection | Connected to DC input rail (e.g., +12 V, +24 V); reverse-biased during normal operation |
Key Features
| Feature | Design Value |
|---|---|
| Glass passivated junction | Ensures long-term VBR stability and low parameter drift across temperature and life cycle |
| Fast response time <1.0 ps | Enables clamping before transient energy couples into sensitive downstream ICs |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Validated for automotive ECU and power module protection without additional filtering |
| Moisture sensitivity level 1 | Eliminates bake requirement prior to reflow, supporting standard SMT assembly |
| Halogen-free & RoHS compliant | Meets IPC-1752A environmental reporting and end-of-life disposal requirements |
Applications
| Automotive Body Control Module (BCM) | Industrial DC Power Input Stage |
|---|---|
Use Scenario: Protects 12 V supply rail of BCM against load dump and alternator ripple transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery feed and DC-DC converter input. Use Value: Clamps surges to ≤45.7 V, preventing overvoltage damage to 36 V-rated buck controller and microcontroller LDOs. | Use Scenario: Shields programmable logic controller (PLC) 24 V DC input from field-wiring inductive kickback. IC Role / Device Role / Timing Role: Primary surge suppression device on terminal block side of DIN-rail power supply. Use Value: Absorbs 1000 W pulses without degradation, maintaining system uptime in factory automation environments. |
| Consumer AC-DC Adapter Output | Telecom Remote Radio Unit (RRU) Power Interface |
Use Scenario: Safeguards secondary-side 5–12 V outputs of wall adapters against ESD and lightning-induced surges. IC Role / Device Role / Timing Role: Final-stage TVS after output filter, before USB or barrel-jack connector. Use Value: Low 1 µA leakage at 28.2 V avoids standby current penalty; SMB footprint fits compact adapter PCBs. | Use Scenario: Protects 48 V DC power input of outdoor RRU against induced surges from nearby lightning strikes. IC Role / Device Role / Timing Role: First-line defense upstream of hot-swap controller and intermediate bus converter. Use Value: Withstands repeated 21.9 A surges while maintaining <1 µA leakage, preserving signal integrity in RF front-end. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ33A (Bourns) | Same DO-214AA package, identical VWM (28.2 V), VC = 48.4 V @ 20.7 A - 2.7 V higher clamping | Slightly higher clamping reduces margin for 36 V-rated downstream ICs | Select when tighter VBR tolerance (±5%) is required; verify clamping headroom in final design |
| P6SMB33A (ON Semiconductor) | VWM = 28.2 V, VC = 45.7 V @ 21.9 A - identical clamping, but RθJA = 110 °C/W vs. 100 °C/W | Lower thermal efficiency may limit sustained surge duty cycle in high-ambient enclosures | Prefer for cost-sensitive consumer designs where ambient stays below 70 °C |
Compared with SMBJ33A and P6SMB33A, the 1KSMB33A offers identical clamping performance to P6SMB33A but superior thermal resistance (RθJA = 100 °C/W), making it better suited for thermally constrained automotive and industrial layouts where board-level heat sinking is limited.
Availability
1KSMB33A is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC power inputs, and telecom remote radio unit interfaces requiring stable component supply and full traceability.
Supply support for 1KSMB33A 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving automotive, industrial, and consumer markets since 1979.
The 1KSMB series is part of TSC's transient voltage suppressor portfolio, engineered specifically for robust, high-power surge immunity in harsh-environment DC power systems with stringent reliability and regulatory compliance requirements.
FAQ
What is the polarity configuration of the 1KSMB33A?
The 1KSMB33A is a unidirectional TVS diode, with cathode marked by a band on the DO-214AA package. It conducts only during reverse overvoltage events and blocks forward current like a standard rectifier. This configuration suits DC power line protection where polarity is fixed and reverse transients dominate.
Does the 1KSMB33A meet automotive EMC standards?
Yes, the 1KSMB33A meets ISO 7637-2 test requirements for Pulse 1 (inductive load disconnect), Pulse 2a (sudden load removal), Pulse 2b (supply interruption), Pulse 3a/3b (capacitive coupling), making it suitable for automotive body electronics and infotainment power inputs without supplemental filtering.
What is the maximum clamping voltage of the 1KSMB33A under surge conditions?
The 1KSMB33A has a maximum clamping voltage VC of 45.7 V when subjected to a 10/1000 µs surge current of 21.9 A. This value is guaranteed across temperature and process variation, providing consistent overvoltage protection for downstream 36 V-rated components.
Can the 1KSMB33A be used in bidirectional applications?
No - the 1KSMB33A is unidirectional. For bidirectional transient suppression, use the 1KSMB33CA variant, which features symmetrical breakdown in both polarities and uses the N10Q marking code. The 'A' suffix explicitly denotes unidirectional construction.
What is the moisture sensitivity level (MSL) rating for the 1KSMB33A?
The 1KSMB33A is rated MSL Level 1 per J-STD-020, meaning it can be stored indefinitely at ≤30 °C/60% RH and placed directly into reflow without baking. This simplifies manufacturing flow and eliminates moisture-related popcorning risk during lead-free soldering.
1KSMB33A 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:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28.2V
- Voltage - Breakdown (Min):
- 31.4V
- Voltage - Clamping (Max) @ Ipp:
- 45.7V
- Current - Peak Pulse (10/1000µs):
- 21.9A
- Power - Peak Pulse:
- 1000W (1kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
1KSMB33A FAQ
1.How can I place an order for 1KSMB33A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1KSMB33A 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 1KSMB33A reliable?
The price and inventory of 1KSMB33A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1KSMB33A is usually 5 days.
3.What payment methods are accepted for 1KSMB33A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1KSMB33A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1KSMB33A?
1KSMB33A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1KSMB33A 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 1KSMB33A?
For technical support, including 1KSMB33A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1KSMB33A requirements.
6.How does Aetrix verify that 1KSMB33A is sourced from the original manufacturer or authorized distributors?
All 1KSMB33A 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 1KSMB33A meets industry standards.
7.What is the process for return or replacement of 1KSMB33A?
All 1KSMB33A units undergo pre-shipment inspection (PSI). If there is an issue with 1KSMB33A, 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 1KSMB33A part is unused and in its original packaging.
Return procedure for 1KSMB33A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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