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Taiwan Semiconductor Corporation 1KSMB91A
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- Part No.:
- 1KSMB91A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1KSMB91A.pdf
- Description:
- TVS DIODE 77.8VWM 125VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:6,426
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Product details
Overview
1KSMB91A from Taiwan Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in DO-214AA (SMB) package, rated for 1000W peak pulse power, 86.5–95.5V breakdown voltage (VBR), and 125V maximum clamping voltage (VC@IPP). It protects DC power rails in switching mode power supplies and consumer displays against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the 1KSMB91A datasheet, 1KSMB91A pinout, 1KSMB91A application, or 1KSMB91A equivalent, key selection criteria include unidirectional polarity, 77.8V stand-off voltage (VWM), 1.0mA test current, 1.0µA max reverse leakage, and 8.0A peak impulse current - all critical for automotive-grade surge immunity in compact SMB layouts.
Technical Context
The 1KSMB91A operates as a silicon avalanche diode with glass-passivated junction, delivering sub-1.0ps response time from 0V to VBR(min). Its unidirectional configuration enables asymmetric clamping on positive-going transients only, with cathode-band polarity marking per DO-214AA mechanical standard.
Thermal performance is defined by 20°C/W junction-to-lead (RθJL) and 100°C/W junction-to-ambient (RθJA) resistance. It supports steady-state power dissipation of 5W at 25°C ambient and withstands 100A non-repetitive forward surge (8.3ms half-sine) per JESD201 Class 2 whisker-tested matte tin leads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/max) | 86.5V / 95.5V - defines minimum and maximum voltage at which avalanche conduction begins under 1.0mA test current |
| VWM | 77.8V - maximum continuous reverse operating voltage before significant leakage occurs |
| VC@IPP | 125V - clamped voltage seen across device during 8.0A 10/1000µs transient, limiting downstream stress |
| PPPSM | 1000W - peak pulse power handling capability for single 10/1000µs waveform |
| IPP | 8.0A - peak impulse current corresponding to 125V clamping, used for PCB trace sizing |
| TJ(max) | 175°C - maximum junction temperature enabling operation in high-ambient industrial environments |
| Package | DO-214AA (SMB) - standardized surface-mount outline with 0.110g mass and UL 94V-0 molding compound |
Pinout & Package
DO-214AA (SMB) package: molded plastic case with cathode band marking; dual-leaded, gull-wing surface-mount format; lead finish: matte tin per J-STD-002; polarity indicated by cathode band on cathode terminal.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient return path | Connected to ground or low-impedance reference; carries full surge current during clamping |
| Cathode | Protected line input | Connected to DC rail being protected; voltage referenced to anode during overvoltage event |
Key Features
| Feature | Design Value |
|---|---|
| Glass passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity exposure |
| Sub-1.0ps response time | Enables clamping before transient energy couples into sensitive downstream ICs or controllers |
| ISO 7637-2 compliance | Validated for automotive load-dump and supply-line transient immunity (Pulse 1/2a/2b/3a/3b) |
| Moisture sensitivity level 1 | Eliminates need for baking prior to reflow, supporting standard SMT assembly without special handling |
| RoHS & halogen-free | Meets IEC 61249-2-21 and EU RoHS Directive for environmentally compliant electronics manufacturing |
Applications
| Switching Mode Power Supply (SMPS) | Consumer Display Power Rail |
|---|---|
Use Scenario: Protection of +12V or +24V secondary-side DC output against inductive kickback and ESD events during hot-plug or fault conditions. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between output rail and ground, clamping transients before they reach DC-DC controller or load. Use Value: Limits voltage excursion to ≤125V during 10/1000µs surges, preserving MOSFET gate oxide integrity and feedback resistor networks. | Use Scenario: Surge suppression on main DC input of LCD/LED TV power board exposed to AC line transients and nearby EMI sources. IC Role / Device Role / Timing Role: Primary-level transient absorber on bulk DC bus, positioned upstream of PFC stage and main converter. Use Value: Withstands 1000W peak pulses while maintaining 77.8V stand-off, preventing false triggering during normal 85–265VAC operation. |
| Automotive Body Control Module (BCM) | Industrial Adapter Input Stage |
Use Scenario: Input protection for 12V/24V BCM microcontroller power domain subjected to ISO 7637-2 Pulse 1 (inductive load dump) and Pulse 3b (capacitive coupling). IC Role / Device Role / Timing Role: Unidirectional clamp on switched battery rail, referenced to chassis ground with cathode tied to rail. Use Value: Clamps to 125V within <1.0ps, meeting OEM requirements for transient immunity without derating due to thermal resistance (RθJL = 20°C/W). | Use Scenario: Input-stage protection for universal-input AC/DC adapter handling 100–240VAC mains with variable load profiles. IC Role / Device Role / Timing Role: Secondary-side TVS on DC output, safeguarding USB-C PD negotiation circuitry and load switches. Use Value: 1.0µA max reverse leakage at 77.8V ensures minimal standby power loss; DO-214AA footprint allows high-density layout in space-constrained adapters. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ90A | VBR = 90–100V, VC = 121V @ 8.3A, same DO-214AA package | Slightly lower clamping voltage but 3% tighter VBR tolerance; identical thermal specs | Select SMBJ90A when tighter VBR distribution and marginally lower clamping are required for precision rail protection. |
| 1.5SMC91A | VBR = 86.5–95.5V, VC = 125V @ 8.0A, DO-214AB (SMC) package - 2.5× larger footprint | Same electrical specs but higher thermal mass; RθJA = 50°C/W vs. 100°C/W for 1KSMB91A | Choose 1.5SMC91A only if board layout permits larger SMC package and higher steady-state power margin is needed. |
Compared with SMBJ90A and 1.5SMC91A, the 1KSMB91A offers optimal balance of compact DO-214AA footprint, 1000W surge rating, and automotive-grade ISO 7637-2 compliance - making it preferred for space-constrained, high-reliability DC rail protection where thermal management is via PCB copper rather than heatsinking.
Availability
1KSMB91A is available at Aetrix Electronics and suitable for switching mode power supplies, consumer display power rails, and automotive body control modules requiring stable component supply with full traceability and lifecycle support.
Supply support for 1KSMB91A 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, headquartered in Hsinchu Science Park.
The 1KSMB series is designed specifically for high-power, surface-mount transient suppression in automotive, industrial, and consumer power systems - emphasizing robustness, automated assembly compatibility, and international surge immunity standards.
FAQ
What is the polarity configuration of the 1KSMB91A?
The 1KSMB91A is a unidirectional TVS diode with cathode-band marking indicating the cathode terminal. When installed, the cathode connects to the protected DC rail and the anode to ground, enabling clamping only on positive transients relative to ground. This configuration matches standard DC power rail protection topology and is confirmed by its "A" suffix (vs. "CA" for bidirectional variants).
Does the 1KSMB91A meet automotive transient immunity standards?
Yes, the 1KSMB91A meets ISO 7637-2 requirements for Pulse 1 (inductive load dump), Pulse 2a/2b (supply interruption), and Pulse 3a/3b (capacitive coupling), as explicitly stated in the official Taiwan Semiconductor datasheet Version I2102. Its 1000W peak pulse rating and 125V clamping voltage ensure compliance under worst-case 12V and 24V system conditions.
What is the maximum steady-state power dissipation for the 1KSMB91A?
The 1KSMB91A has a steady-state power dissipation (PD) rating of 5W at TA = 25°C, as specified in the Absolute Maximum Ratings table. Derating is required above 25°C ambient per the Pulse Derating Curve (Fig.2), with thermal resistance values of RθJL = 20°C/W and RθJA = 100°C/W defining its thermal behavior in typical PCB layouts.
How does the 1KSMB91A compare to the 1KSMB91CA variant?
The 1KSMB91CA is the bidirectional counterpart of the 1KSMB91A, sharing identical VBR, VC, and PPPSM ratings but enabling symmetrical clamping for AC-coupled or floating-rail applications. The 1KSMB91A is strictly unidirectional and marked with code "B10B", whereas 1KSMB91CA uses "O10B" and lacks polarity marking - making them functionally distinct and not interchangeable without circuit redesign.
Is the 1KSMB91A compatible with lead-free reflow soldering processes?
Yes, the 1KSMB91A features matte tin-plated leads compliant with J-STD-002 and moisture sensitivity level 1 per J-STD-020, allowing direct placement into standard lead-free reflow profiles (peak temperature up to 260°C) without pre-baking. Its DO-214AA package and UL 94V-0 molding compound are qualified for IPC/JEDEC J-STD-020D.2 requirements.
1KSMB91A 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):
- 77.8V
- Voltage - Breakdown (Min):
- 86.5V
- Voltage - Clamping (Max) @ Ipp:
- 125V
- Current - Peak Pulse (10/1000µs):
- 8A
- 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)
1KSMB91A FAQ
1.How can I place an order for 1KSMB91A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1KSMB91A 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 1KSMB91A reliable?
The price and inventory of 1KSMB91A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1KSMB91A is usually 5 days.
3.What payment methods are accepted for 1KSMB91A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1KSMB91A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1KSMB91A?
1KSMB91A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1KSMB91A 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 1KSMB91A?
For technical support, including 1KSMB91A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1KSMB91A requirements.
6.How does Aetrix verify that 1KSMB91A is sourced from the original manufacturer or authorized distributors?
All 1KSMB91A 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 1KSMB91A meets industry standards.
7.What is the process for return or replacement of 1KSMB91A?
All 1KSMB91A units undergo pre-shipment inspection (PSI). If there is an issue with 1KSMB91A, 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 1KSMB91A part is unused and in its original packaging.
Return procedure for 1KSMB91A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1KSMB91A Tags
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