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Taiwan Semiconductor Corporation SMCJ45
- Part No.:
- SMCJ45
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ45.pdf
- Description:
- 1500W, 55.6V, 10%, UNIDIRECTIONA
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
SMCJ45 from Taiwan Semiconductor is a unidirectional 1500W surface-mount transient voltage suppressor (TVS) in DO-214AB (SMC) package, with 45V working stand-off voltage (VWM), 50–61.1V breakdown voltage (VBR), and 80.3V maximum clamping voltage (VC) at 19A peak pulse current - designed for automotive load-dump and inductive switching protection in power supply rails.
For engineers reviewing the SMCJ45 datasheet, SMCJ45 pinout, SMCJ45 application, or SMCJ45 equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, junction temperature limits (−55°C to +150°C), moisture sensitivity level (MSL 1), and compatibility with automated SMT placement on 12V/24V vehicle subsystems.
Technical Context
The SMCJ45 operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its VBR range (50–61.1V at 1mA test current). Its glass-passivated junction enables sub-1ps response time and low leakage (<1μA at 45V), supporting fast transient suppression in automotive ECUs and industrial controllers.
Thermal design relies on RθJA = 55°C/W and RθJC = 10°C/W, enabling 5W steady-state dissipation at 25°C ambient. It meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements for high-reliability PCB mounting.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 45 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC rail margin for 12V/24V systems. |
| VBR min/max | 50 / 61.1 V @ 1 mA - Breakdown threshold range ensures consistent turn-on across production lots under standardized test conditions. |
| VC @ IPPM | 80.3 V @ 19 A - Clamping voltage during 10/1000μs surge; limits downstream IC stress during ISO 7637-2 Pulse 5a events. |
| PPK | 1500 W - Peak pulse power rating per 1ms non-repetitive waveform; supports single-event load-dump energy absorption. |
| TJ max | +150 °C - Maximum junction temperature; enables operation in under-hood environments without derating below 100% power. |
| IR @ VWM | <1 μA - Reverse leakage at rated stand-off voltage; minimizes quiescent power loss in always-on automotive modules. |
Pinout & Package
Package: DO-214AB (SMC), surface-mount, matte tin-plated leads, cathode band marked on body for polarity identification. Weight: 0.210 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-impedance return path; forms clamping loop with cathode during transients. |
| Cathode | High-side surge input terminal | Connected to protected line (e.g., battery rail); avalanche conduction occurs from cathode to anode when VAK > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive switch-off), Pulse 2a/2b (battery disconnection), and Pulse 3a/3b (switching noise) - eliminates need for external filtering in automotive OEM designs. |
| Sub-1 ps response time | Enables suppression of EFT bursts and nanosecond-scale transients before sensitive logic or analog circuitry responds. |
| MSL 1 rating | Permits unlimited floor life and reflow soldering without baking - reduces manufacturing overhead in high-volume SMT lines. |
| RoHS & halogen-free | Complies with IEC 61249-2-21 and EU RoHS Directive 2011/65/EU - satisfies environmental compliance for global automotive Tier 1 supply chains. |
Applications
| Automotive Body Control Module (BCM) | Industrial PLC Digital Input Protection |
|---|---|
Use Scenario: Protects microcontroller GPIO and CAN transceiver power rails from alternator load-dump spikes up to 120V in 12V vehicle architectures. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between battery rail and local LDO input, clamping within 80.3V to preserve downstream 5V/3.3V regulator headroom. Use Value: Prevents latch-up or permanent damage to MCU I/O during ISO 7637-2 Pulse 5a events without requiring series impedance or active regulation. | Use Scenario: Shields 24V digital input channels from relay coil flyback and motor drive coupling in factory automation cabinets. IC Role / Device Role / Timing Role: Standoff-rated TVS connected across optocoupler input terminals, absorbing 1500W surges while maintaining <1μA leakage at 24V nominal. Use Value: Enables direct connection to field wiring without external RC snubbers, reducing BOM count and board space in DIN-rail mounted I/O modules. |
| LED Driver Power Stage | Telecom Power Supply Input |
Use Scenario: Safeguards buck converter MOSFETs and gate drivers from inductive kickback during LED string short-circuit events. IC Role / Device Role / Timing Role: Parallel-connected TVS on high-side switch node, clamping voltage to 80.3V to prevent VDS overstress on 100V-rated FETs. Use Value: Extends FET lifetime by limiting dv/dt-induced avalanche energy, eliminating need for larger, costlier 150V devices. | Use Scenario: Provides primary-level surge immunity on −48V telecom rectifier outputs exposed to lightning-induced surges on long cable runs. IC Role / Device Role / Timing Role: Bidirectional-capable variant (SMCJ45CA) used in differential mode across output rails, but SMCJ45 serves as unidirectional clamp to chassis ground. Use Value: Meets GR-1089-CORE Level 3 immunity requirements with single-device solution, avoiding dual-diode arrays or MOV hybrids. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ45A | Lower PPK (600W), smaller SMB package (DO-214AA), higher VC (93.6V @ 10.3A) | Not suitable for ISO 7637-2 Pulse 5a; limited to lower-energy ESD/EFT scenarios | Select SMCJ45 when 1500W clamping and DO-214AB thermal mass are required for automotive load-dump. |
| 1.5KE45A | Through-hole TO-204AE (DO-41), same VWM/VC specs, but slower response (>1ns) and no MSL 1 rating | Requires wave soldering; incompatible with fully SMT production lines | Choose SMCJ45 for automated assembly, high-reliability under-hood use, and compliance with modern automotive electronics standards. |
Compared with SMBJ45A and 1.5KE45A, the SMCJ45 delivers superior surge handling in a surface-mount format with verified ISO 7637-2 compliance and zero moisture sensitivity - making it the preferred choice for new automotive and industrial designs requiring robust, scalable TVS protection.
Availability
SMCJ45 is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC input protection, LED driver power stages, and telecom power supply inputs requiring stable component supply across extended temperature and surge stress conditions.
Supply support for SMCJ45 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, and rectifiers for automotive, industrial, and consumer markets.
The SMCJ series was developed specifically for high-energy transient suppression in 12V/24V automotive systems, targeting ISO 7637-2 compliance and automated SMT manufacturability without thermal or reliability trade-offs.
FAQ
What is the clamping voltage of SMCJ45 under standard test conditions?
The SMCJ45 has a maximum clamping voltage (VC) of 80.3 V at 19 A peak pulse current (IPPM), measured using the 10/1000 μs double-exponential surge waveform per Fig.5 in the datasheet. This value defines the upper voltage limit imposed on protected circuits during transient events and is critical for ensuring downstream ICs remain within absolute maximum ratings.
Is SMCJ45 suitable for bidirectional transient protection?
No - the SMCJ45 is a unidirectional TVS diode intended for DC-biased applications like automotive battery rails. For bidirectional protection, the SMCJ45CA variant must be used. The SMCJ45's cathode band marking and asymmetric IV curve confirm its unidirectional functionality; applying reverse bias beyond VWM will not trigger clamping in the forward direction.
Does SMCJ45 meet automotive qualification standards?
Yes - the SMCJ45 meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements for electrical disturbances in road vehicles. It is also qualified to JESD201 Class 2 for tin whisker resistance and rated MSL 1 per J-STD-020, supporting lead-free reflow without preconditioning - fulfilling core AEC-Q101 pre-qualification expectations for discrete TVS devices.
What is the thermal resistance from junction to ambient for SMCJ45?
The SMCJ45 has a typical junction-to-ambient thermal resistance (RθJA) of 55°C/W under standard JEDEC PCB mounting conditions (2s2p copper pad layout). This value assumes no additional heatsinking and determines allowable power dissipation at elevated ambient temperatures - for example, at 85°C ambient, maximum steady-state power drops to ~3 W before exceeding TJ,max = 150°C.
Can SMCJ45 replace SMCJ45A in existing designs?
No - the SMCJ45 and SMCJ45A differ in breakdown voltage tolerance: SMCJ45 specifies VBR = 50–61.1 V, while SMCJ45A tightens this to 50–55.3 V. This narrower range improves clamping consistency but may affect system-level margin analysis. Substitution requires validation of worst-case clamping behavior and verification that the tighter VBR does not cause premature conduction in marginal operating conditions.
SMCJ45 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AB, SMC
- Series:
- SMCJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 80.3V
- Current - Peak Pulse (10/1000µs):
- 19A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMC)
SMCJ45 FAQ
1.How can I place an order for SMCJ45 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ45 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 SMCJ45 reliable?
The price and inventory of SMCJ45 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ45 is usually 5 days.
3.What payment methods are accepted for SMCJ45?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ45 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ45?
SMCJ45 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ45 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 SMCJ45?
For technical support, including SMCJ45 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ45 requirements.
6.How does Aetrix verify that SMCJ45 is sourced from the original manufacturer or authorized distributors?
All SMCJ45 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 SMCJ45 meets industry standards.
7.What is the process for return or replacement of SMCJ45?
All SMCJ45 units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ45, 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 SMCJ45 part is unused and in its original packaging.
Return procedure for SMCJ45:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ45 Tags
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